DOCUMENT RELEASE AND CHANGE FORM Doc No: RPP … Library/011819... · Doc No: RPP-PLAN-57352 Rev. 01 1b. Project Number: ☒ N/A 1 SPF-001 (Rev.0) ... The P-Scan system returns high

DOCUMENT RELEASE AND CHANGE FORM Prepared For the U.S. Department of Energy, Assistant Secretary for Environmental Management By Washington River Protection Solutions, LLC., PO Box 850, Richland, WA 99352 Contractor For U.S. Department of Energy, Office of River Protection, under Contract DE-AC27-08RV14800

1a. Doc No: RPP-PLAN-57352 Rev. 01

1b. Project Number: ☒ N/A

1 SPF-001 (Rev.0)

TRADEMARK DISCLAIMER: Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof or its contractors or subcontractors. Printed in the United States of America.

Release Stamp

2. Document Title

Double-Shell Tank Integrity Improvement Plan

3. Design Verification Required

☐ Yes ☐ No

4. USQ Number ☒ N/A 5. PrHA Number ☒ N/A

Rev.

6. USQ Screening:

a. Does the change introduce any new failure modes to the equipment? ☐ Yes ☒ No

Basis is required for Yes:

b. Does the change increase the probability of existing failure modes? ☐ Yes ☒ No


c. For Safety Significant equipment, does the change require a modification to Chapter 4 of the DSA and/or FRED? ☐ Yes ☐ No ☒ N/A


7. Description of Change and Justification (Use Continuation pages as needed)

New Document

8. Approvals

Title Name Signature Date

Clearance Review RAYMER, JULIA R RAYMER, JULIA R 07/20/2015

Document Control Approval RAYMER, JULIA R RAYMER, JULIA R 07/20/2015

Originator GARFIELD, JOHN GARFIELD, JOHN 05/26/2015

Other Approver BOOMER, KAYLE D BOOMER, KAYLE D 06/25/2015

Responsible Manager BAIDE, DAN BAIDE, DAN 06/25/2015

9. Clearance Review:

Restriction Type:

☒ Public

☐ Undefined

☐ Unclassified Controlled Nuclear Information (UCNI)

☐ Export Control Information (ECI)

☐ Official Use Only Exemption 2-Circumvention of Statute (OUO-2)

☐ Official Use Only Exemption 3-Statutory Exemption (OUO-3)

☐ Official Use Only Exemption 4-Commercial/Proprietary (OUO-4)

☐ Official Use Only Exemption 5-Privileged Information (OUO-5)

☐ Official Use Only Exemption 6-Personal Privacy (OUO-6)

☐ Official Use Only Exemption 7-Law Enforcement (OUO-7)

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Jul 20, 2015DATE:

JRR 7/20/15

DOCUMENT RELEASE AND CHANGE FORM Doc No: RPP-PLAN-57352 Rev. 01

2 SPF-001 (Rev.0)

10. Distribution:

Name Organization

BAIDE, DAN TFP ENGINEERING

BARNES, TRAVIS J TANK AND PIPELINE INTEGRITY

BOOMER, KAYLE D TANK AND PIPELINE INTEGRITY

CASTLEBERRY, JIM L TFP PROJECT MANAGEMENT

FEERO, AMIE J TANK AND PIPELINE INTEGRITY

GARFIELD, JOHN TANK AND PIPELINE INTEGRITY

GUNTER, JASON R TANK AND PIPELINE INTEGRITY

JOHNSON, JEREMY

LITTLE, DAVID B ENGINEERING

TURKNETT, MARILYN J TANK AND PIPELINE INTEGRITY

VAZQUEZ, BRANDON J TANK AND PIPELINE INTEGRITY

WASHENFELDER, DENNIS TANK AND PIPELINE INTEGRITY

11. TBDs or Holds ☒ N/A

12. Impacted Documents – Engineering ☒ N/A

Document Number Rev. Title

13. Other Related Documents ☒ N/A

Document Number Rev. Title

14. Related Systems, Structures, and Components:

14a. Related Building/Facilities ☐ N/A

241-AN

241-AP

241-AW

241-AY

241-AZ

241-SY

14b. Related Systems ☒ N/A

14c. Related Equipment ID Nos. (EIN) ☒ N/A

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3 SPF-001 (Rev.0)

DOCUMENT RELEASE AND CHANGE FORM CONTINUATION SHEET

Document No: RPP-PLAN-57352 Rev. 01

NA

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RPP-PLAN-57352 7/20/2015 - 12:51 PM 4 of 92

H. K. Lawrence, Email att.

7/20/15 JRR

By Julia Raymer at 1:04 pm, Jul 20, 2015

RPP-PLAN-57352 7/20/2015 - 12:51 PM 5 of 92

Jerry Holloway- See attached e-mail

Brad Page - See attached e-mailSteve Beehler - See attached e-mail


Approved for Public Release; Further Dissemination Unlimited

7/20/15

Jeremy Johnson - See attached e-mailDOE-ORP SME

RPP-PLAN-57352 6/30/2015 - 7:04 AM 7 of 88RPP-PLAN-57352 7/20/2015 - 12:51 PM 6 of 92

1

Vorpagel, Lindsay R

From: Holloway, Jerry N

Sent: Tuesday, July 14, 2015 11:52 AM

To: Vorpagel, Lindsay R

Subject: RE: 2nd request - Digital ICR request - RPP-PLAN-57352-01-Record.pdf

Follow Up Flag: Follow up

Flag Status: Completed

Categories: 3 red light

Lindsay,

I approve on behalf of External Affairs.

Jerry

Jerry Holloway

External Affairs Manager

Washington River Protection Solutions,

contractor to the United States Department of Energy

509.372.9953

From: Vorpagel, Lindsay R


To: Cherry, Stephen B; Page, Brad; Roxburgh, Robert T; Holloway, Jerry N; Vorpagel, Lindsay R

Subject: 2nd request - Digital ICR request - RPP-PLAN-57352-01-Record.pdf

The below ICR request still needs a response from External Affairs and Legal please.

Sincerely,

Lindsay Vorpagel, WRPS External Affairs and Procurement SEAPC representative 509-376-5380


Sent: Monday, July 06, 2015 10:15 AM

To: Beehler, Stephen J; Cherry, Stephen B; Page, Brad; Poynor, Tara N; Roxburgh, Robert T; Vorpagel, Lindsay R

Subject: Digital ICR request - RPP-PLAN-57352-01-Record.pdf

Please coordinate with your department colleagues as to who will do the below review. After reviewing, please send

your email response to me of-

approval,

RPP-PLAN-57352 7/20/2015 - 12:51 PM 7 of 92

1

Vorpagel, Lindsay R

From: Page, Brad

Sent: Thursday, July 16, 2015 11:29 AM

To: Vorpagel, Lindsay R; Cherry, Stephen B

Subject: RE: 3rd request - Digital ICR request - RPP-PLAN-57352-01-Record.pdf



Categories: 2 yellow light

Lindsay,

I have reviewed the ICR and approve its release on behalf of legal.

Brad


Sent: Thursday, July 16, 2015 7:15 AM

To: Page, Brad; Cherry, Stephen B; Vorpagel, Lindsay R

Subject: 3rd request - Digital ICR request - RPP-PLAN-57352-01-Record.pdf

Please see below -

Sincerely,




To: Cherry, Stephen B; Page, Brad; Roxburgh, Robert T; Holloway, Jerry N; Vorpagel, Lindsay R

Subject: 2nd request - Digital ICR request - RPP-PLAN-57352-01-Record.pdf

The below ICR request still needs a response from External Affairs and Legal please.

Sincerely,

Lindsay Vorpagel, WRPS External Affairs and Procurement SEAPC representative

RPP-PLAN-57352 7/20/2015 - 12:51 PM 8 of 92

1

Vorpagel, Lindsay R

From: Beehler, Stephen J

Sent: Thursday, July 09, 2015 12:00 PM

To: Vorpagel, Lindsay R

Cc: Poynor, Tara N

Subject: DOCUMENT REVIEW REQUEST - DST Integrity



Categories: 1 green light

Lindsay-

The document contained in the link below has been reviewed and approved by ORP Subject Matter Expert Jeremy

Johnson. His email noting such is below. I concur on behalf of ORP Public Affairs. Please consider this email as approval

to clear the document for public release in lieu of providing signatures on the ICR form.

Regards,

Steve BeehlerSteve BeehlerSteve BeehlerSteve Beehler Media Relations Specialist

North Wind Solutions, LLC

General Support Services Contractor

Office of River Protection

Office - 509.376.4637

Cell - 509.521.4498

[email protected] [email protected]

From: Johnson, Jeremy M

Sent: Wednesday, July 08, 2015 1:32 PM

To: Beehler, Stephen J

Subject: RE: DOCUMENT REVIEE REQUEST - DST Integrity

I reviewed, ok to release.

Jeremy Johnson

Office of River Protection

Tank Farms Projects

509-376-1866


Sent: Monday, July 06, 2015 10:15 AM

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2

To: Beehler, Stephen J; Cherry, Stephen B; Page, Brad; Poynor, Tara N; Roxburgh, Robert T; Vorpagel, Lindsay R

Subject: Digital ICR request - RPP-PLAN-57352-01-Record.pdf

Please coordinate with your department colleagues as to who will do the below review. After reviewing, please send

your email response to me of-

approval,

OR

approval with edits

OR

non-approval with comments

To Review –

RPP-PLAN-57352-01-Record.pdf

Thanks!

Sincerely,


RPP-PLAN-57352 7/20/2015 - 12:51 PM 10 of 92

Tank Operations Contractor (T0C) Record of Revision

RPP-PLAN-57352, Rev. 1


Change Control Record

Rev Description of change Author Manager

1 Deleted action to Sample Tank AY-102 Prioritized Annulus Sampling

J. S. Garfield

D. G. Baide

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A-6002-767 (REV 3)

RPP-PLAN-57352 Rev. 1

Double-Shell Tank Integrity Improvement Plan Author Names:

J. S. Garfield, B. J. Vazquez, J. R. Gunter, A. J. Feero, & K. D. Boomer Washington River Protection Solutions, LLC

Richland, WA 99352 U.S. Department of Energy Contract DE-AC27-08RV14800

EDT/ECN: DRCF UC: N/A

Cost Center: N/A Charge Code: N/A

B&R Code: N/A Total Pages:

Key Words: double-shell tanks, integrity, corrosion

Abstract: The High-level Waste Integrity Assessment Panel are nationally recognized experts

in corrosion chemistry and structural tank integrity issues who were convened three times in

FY-2013 and FY-2014 to review the Tank 241-AY-102 status along with the integrity of all

double-shell tanks. The Panel identified specific recommendations documented in RPP-

ASMT-57582. WRPS engineering staff developed a path forward for each recommendation in

this Implementation Plan.

TRADEMARK DISCLAIMER. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors.

Release Approval Date Release Stamp

Approved For Public Release

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Jul 20, 2015DATE:

92 JRR 7/20/15



J. S. Garfield A E M Consulting, LLC K. D. Boomer B. J. Vazquez J. R. Gunter A. J. Feero Washington River Protection Solutions, LLC

Date Published

June, 2015

Prepared for the U.S. Department of Energy Office of River Protection

Contractor for the U.S. Department of Energy Office of River Protection under Contract DE-AC27-08RV14800

P.O. Box 850 Richland, Washington

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ES-1

EXECUTIVE SUMMARY

The Hanford Site Tank Operations Contractor (TOC), Washington River Protection Solutions

LLC (WRPS), has contracted an expert panel to provide advice and recommendations for the

Double-Shell Tank (DST) Integrity Program. The purpose of this DST Integrity Improvement

Plan is to translate the High-level Waste Integrity Assessment Panel (HIAP) recommendations to

specific project activities that are technically and practically responsive. These project actions in

Figure ES-1 are developed conceptually to address the technical justification and provide a

definition of scope and schedule for budgeting consideration. The numbering provides an index

to the narrative sections in this document. Revision 1 deletes the Tank-AY-102 bottom plate

sampling activities and updates schedules and priorities on the remaining tasks.

Figure ES-1. Proposed Actions to the Recommendations Given by the High-Level Waste

Integrity Assessment Panel

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ES-2

The HIAP reviewed the DST integrity issues in two meetings and addressed forensic

examination of Tank 241-AY-102 (AY-102) in a third meeting. The two integrity issue

meetings placed an emphasis on corrosion and degradation mechanisms. The third meeting was

in August 2014, addressed commercial and nuclear industry methods to examine the leak site

pre- and post-retrieval. The HIAP meetings were documented as follows:

RPP-ASMT-56329 9/13 Workshop



The initial integrity meeting was in September 2013, and discussed the Tank AY-102 leak

assessment. The second meeting was in April 2014, and discussed the extent of condition

reviews from the leak assessment along with an overall program review. The focus of this

implementation plan is to address the recommendations from the first two meetings, which the

HIAP concentrated on two concerns:

• No Early warning – Determine why the existing DST Integrity Program did not

predict a primary tank failure or provide early warning of the pending failure.

• Program improvements – Recommend activities to either predict a primary tank

failure or increase the probability of early warning.

The project activities, which implement the HIAP recommendations listed in Table ES-1, have

been developed at a pre-conceptual level for funding beginning in fiscal year (FY) 2016. The

tasks identified to implement the panel recommendations were reviewed with the HIAP in the

August 2014 meeting. WRPS provided a prioritization and path forward for each of the tasks as

discussed in Section 6.0 and summarized in Figure ES-2.

In the August 2014, meeting the HIAP provided additional recommendations regarding post-

retrieval forensic assessment of Tank AY-102 to facilitate a conclusion on why the leak

occurred. Implementation of these recommendations will be addressed separately.

Since the Rev. 0 was issued, it was determined that the AY-102 Core sample and analysis

activities would interfere with tank retrieval. These activities were deleted and 5.3.3 (Sample

AY-102 Annulus with Robotic Crawler) was elevated in priority to address the HIAP concern

with AY-102 leak status.

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ES-3

Figure ES-2. Double-Shell Tank Integrity Task Priorities

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i

CONTENTS

1.0 INTRODUCTION ............................................................................................................ 1-1

1.1 Objectives – Predict a Failure or Identify Early Warnings .................................... 1-3

1.2 High-Level Waste Integrity Assessment Panel Findings ....................................... 1-3

1.2.1 Why Tank AY-102 Leak Was Not Predicted ........................................... 1-3

1.2.2 Possible Degradation Mechanisms in Tank AY-102 ................................ 1-4

1.2.3 Specific High-Level Waste Integrity Assessment Panel

Recommendations ..................................................................................... 1-4

1.2.4 Supplemental Panel Recommendations From August Meeting ............... 1-7

2.0 SUMMARY OF PROGRAM IMPROVEMENTS ........................................................... 2-1

3.0 DATA ANALYSIS AND INTERPRETATION ACTIVITIES ....................................... 3-1

3.1 Review Tank Chemistry History ............................................................................ 3-1

3.1.1 Document Tank Chemistry History .......................................................... 3-1

3.2 Rank Tank Leak Risks ........................................................................................... 3-2

3.2.1 Qualitative Risk Ranking for All Double-Shell Tanks ............................. 3-2

Figure 3-2. Schedule to Update Qualitative Risk Ranking for All

Double-Shell Tanks ................................................................................... 3-3

3.2.2 Risk Analysis Based on Sidewall Ultrasonic Testing Data ...................... 3-3

3.2.3 Double-Shell Tank Risk Analysis Based on Bottom Plate Data............... 3-5

3.3 Validate Double-Shell Tank Integrity Program ..................................................... 3-5

3.3.1 Primary Tank Chemistry Controls ............................................................ 3-5

4.0 IMPROVED DATA GATHERING ACTIVITIES .......................................................... 4-1

4.1 Perform Augmented Wall Scanning Inspections ................................................... 4-1

4.1.1 Develop Electromagnetic Acoustic Transducer and Phased Array .......... 4-1

4.1.2 Evaluate Additional Nondestructive Examination (Flash

Thermography) .......................................................................................... 4-3

4.2 Increase Visual Observations In the Annulus ........................................................ 4-4

4.2.1 Automated Annulus Camera System ........................................................ 4-4

4.3 Visual Observation and NDE of the Primary Tank Bottom ................................... 4-7

4.3.1 Visual – Robotic Crawler in Air Slots ...................................................... 4-7

4.3.2 Visual–Robotic Annulus Air Supply Pipe Inspections ............................. 4-9

4.3.3 Nondestructive Examination–Synthetic Aperture Focusing

Technique and Tandem Synthetic Aperture Focusing Technique .......... 4-12

4.3.4 Nondestructive Examination - Robotic Crawler (Guided Wave in

Air Slots) ................................................................................................. 4-13

4.3.5 Nondestructive Examination–Guided Wave System (Across Tank

Diameter) ................................................................................................ 4-14

4.4 Perform Ultrasonic Testing on Secondary Tank Bottom in the Annulus ............ 4-16

4.4.1 Perform Ultrasonic Testing with Existing Procedure ............................. 4-16

4.5 Optimize Use of Thermocouples for Early Leak Notification ............................. 4-16

4.5.1 Use of Thermocouples to Detect Leaks .................................................. 4-16

4.6 Improved Continous Air Monitoring ................................................................... 4-17

4.6.1 Improved Annulus Air Monitoring Design ............................................. 4-17

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ii

5.0 ENHANCED EXISTING INTEGRITY PROGRAM TO MINIMIZE

DOUBLE-SHELL TANK DEGRADATION................................................................... 5-1

5.1 Corrosion Test Secondary Liner and Leak Detection Pit Steel for Tank AY-

102 .......................................................................................................................... 5-1

5.1.1 2014 Corrosion Work on Tank AY-102 Steel .......................................... 5-1

5.2 Ensure Low Humidity between Primary and Secondary Liners ............................ 5-1

5.2.1 Dehumidifiers on Annulus Air Inlet ......................................................... 5-1

5.3 Sampling and Analysis of Sludge at the Bottom Plate ........................................... 5-4

5.3.1 Core Sample Tank AY-102 at Bottom Plate ............................................. 5-4

5.3.2 Analyze Sample (Corrosion Testing) ........................................................ 5-4

5.3.3 Sample AY-102 Annulus with Robotic Crawler ...................................... 5-4

6.0 CONCLUSIONS AND PATH FORWARD ..................................................................... 6-1

7.0 REFERENCES .................................................................................................................. 7-1

APPENDICES

Appendix A Qualitative Risk Ranking Performance Measures ............................................... A-i

FIGURES

Figure ES-1. Proposed Actions to the Recommendations Given by the High-Level Waste

Integrity Assessment Panel ......................................................................................1

Figure ES-2. Double-Shell Tank Integrity Task Priorities .............................................................3

Figure 1-1. High Level Waste Integrity Assessment Panel Charter ....................................... 1-1

Figure 1-2. Summary of the Proposed Actions and Recommendations ................................. 1-2

Figure 2-1. Double-Shell Tank Integrity Task Priorities ........................................................ 2-1

Figure 3-1. Schedule to Review Tank Chemistry History ...................................................... 3-1

Figure 3-2. Schedule to Update Qualitative Risk Ranking for All Double-Shell Tanks ........ 3-3

Figure 3-3. Schedule for Frequency of Ultrasonic Wall Inspection ....................................... 3-4

Figure 3-4. EPOC Oversight of Tank Chemistry Controls ..................................................... 3-6

Figure 4-1. Force Institute P-Scan Stack System ................................................................... 4-2

Figure 4-2. AGS-2 Magnetic Crawler .................................................................................... 4-2

Figure 4-3. Schedule for Electromagnetic Acoustic Transducer Scans and Phased

Array Ultrasonic Transducers .............................................................................. 4-3

Figure 4-4. Schedule for Flash Thermography ....................................................................... 4-4

Figure 4-5. Conceptual Design for the Annulus Video Monitoring System .......................... 4-5

Figure 4-6. Schedule for a Premium Annulus Video Monitoring System ............................. 4-6

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iii

Figure 4-7. Robotic Air Slot Visual Inspection Crawler ............................................................ 4-7

Figure 4-8. Deployment Method of Crawler Concept ............................................................ 4-8

Figure 4-9. Crawler Oriented on Annulus Floor and Aligned with Air Slot .............................. 4-8

Figure 4-10. Camera Inserted into Refractory Air Slot for Visual Inspection (note:

Primary Tank Hidden from View) ....................................................................... 4-8

Figure 4-11. Schedule for the Robotic Air Slot Visual Inspection Crawler ............................. 4-9

Figure 4-12. Robotic Pipe Crawler ........................................................................................ 4-10

Figure 4-13. Ventilation Air Supply System Overview ......................................................... 4-10

Figure 4-14. Air Supply Piping .............................................................................................. 4-10

Figure 4-15. Schedule for Robotic Annulus Air Supply Crawler .......................................... 4-11

Figure 4-16. FORCE–Extended Arm and Tandem Synthetic Aperture Focusing

Technique for Lower Knuckle Region .............................................................. 4-12

Figure 4-17. Schedule for Ultrasonic Testing using Synthetic Aperture Focusing

Technique and Tandem Synthetic Aperture Focusing Technique ..................... 4-13

Figure 4-18. Schedule for the Robotic Multi-Air Slot Nondestructive Evaluation ................ 4-14

Figure 4-19. Long Range Guided Wave Ultrasonic Testing .................................................. 4-15

Figure 4-20. Schedule for Inspection using Guided Wave Transducers ................................ 4-15

Figure 4-21. Schedule for Improved Annulus Air Monitoring Design .................................. 4-19

Figure 5-1. Proposed Dehumidifier Layout ............................................................................ 5-2

Figure 5-2. Portable Industrial Dehumidifier with Condenser Reheat ................................... 5-2

Figure 5-3. Schedule for Annulus Air Humidity Control ....................................................... 5-4

Figure 5-4. Washington River Protection Solutions Off Riser Sampling System .................. 5-5

Figure 5-5. AREVA Remote Underground Sampler .............................................................. 5-5

Figure 5-6. Schedule for Robotic Annulus Sampling ............................................................. 5-6

TABLES

Table 3-1. Double-Shell Tank Inspection Frequencies ......................................................... 3-4

Table 4-1. Tank AY-101 and Tank AY-102 Thermocouples Operable (8/2012) ............... 4-17

Table 6-1. Double-Shell Tank Integrity Task Priorities and Path Forward (3 Pages) .......... 6-1

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iv

TERMS

Acronyms

CAM continuous air monitoring

CLR Caustic Limits Report

CPP cyclic potentiodynamic polarization

CSS core sampling system

DST double-shell tank

EMAT Electromagnetic Acoustic Transducer

ENRAF Honeywell ENRAF-Nonius 854

EPOC Expert Panel Oversight Committee

FAT factory acceptance test

FY fiscal year

HIAP High-level Waste Integrity Assessment Panel

IHI IHI Southwest Technologies, Inc.

ISL interstitial liquid

LDP leak detection pit

LED light emitting diode

LRGWUT long range guided wave ultrasonic testing

NDE nondestructive examination

OAT operation acceptance test

ORSS off riser sampling system

OSD Operation Specification Document

PAUT phased array ultrasonic testing

PDT performance demonstration test

PNNL Pacific Northwest National Laboratory

PWHT post weld heat treatment

ROM rough order of magnitude

RUS remote underground sampler

SAFT Synthetic Aperture Focusing Technique

SCC stress corrosion cracking

SCE saturated calomel electrode

SSR slow strain rate

SST single-shell tank

T-SAFT Tandem Synthetic Aperture Focusing Testing

UT ultrasonic testing

WRPS Washington River Protection Solutions, LLC

WTP Waste Treatment and Immobilization Plant

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v

Units

% percent

cm2 centimeter squared

ft feet

Gy gray (unit of absorbed radiation)

in. inch

mA milliamp

mV millivolt

sec second

V Volt

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1-1

1.0 INTRODUCTION

The High-Level Waste Integrity Assessment Panel (HIAP), or Panel, reviewed the double-shell

tank (DST) integrity issues with an emphasis on corrosion and degradation mechanisms. HIAP

has met twice to discuss integrity issues. The initial meeting in September 2013, discussed RPP-

ASMT-53793, Tank 241-AY-102 Leak Assessment Report. The second meeting in April 2014,

discussed the extent of condition reviews from the leak assessment along with an overall

program review. The HIAP charter is shown in Figure 1-1.

Figure 1-1. High Level Waste Integrity Assessment Panel Charter

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1-2

HIAP suggestions are indexed by sections in this document and summarized in Figure 1-2. The

HIAP focused on two concerns:

• No early warning – Determine why the existing DST Integrity Program did not predict a

primary tank failure or provide early warning of the pending failure.

• Program improvements – Recommend activities to either predict a primary tank failure or

increase the probability of early warning.

Figure 1-2. Summary of the Proposed Actions and Recommendations

The recommendations were formally documented by HIAP and are summarized in Section 1.2.

HIAP suggestions, shown in Figure 1-2, include addressing the risk of future DST failures,

improvements to monitoring functions, and program or operational improvements that are

preventive in nature.

The tasks identified to implement the panel recommendations were reviewed with the HIAP in

the August 2014 meeting. Washington River Protection Solutions, LLC (WRPS) provided a

prioritization and path forward for each of the tasks as discussed in Section 6.0.

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1-3

The main focus of the HIAP meeting in August 2014 was to address forensic examination of

Tank AY-102 after the waste is retrieved. The goal of this meeting was to develop methods and

procedures for the examination and to determine whether the tank can be repaired and return to

service. The HIAP will provide additional recommendations regarding pre- and post-retrieval

forensic assessment of Tank AY-102 to facilitate a conclusion on why the leak occurred.

1.1 OBJECTIVES – PREDICT A FAILURE OR IDENTIFY EARLY WARNINGS

The purpose of this DST improvement plan is to translate the HIAP recommendations to specific

project activities that are technically and practically responsive. These project actions are

developed conceptually to address the technical justification and provide a definition of scope.

1.2 HIGH-LEVEL WASTE INTEGRITY ASSESSMENT PANEL FINDINGS

The HIAP considered three primary areas to address.

1. Why there was no early warning in the failure of Tank AY-102.

2. Suggestions to increase the probability of early warning.

3. Suggested program improvements. Some of these activities serve the dual purpose of

interrogating sound tanks as well as forensic discovery of the leak mechanism in Tank

AY-102.

1.2.1 Why Tank AY-102 Leak Was Not Predicted

The HIAP focused on four areas that may have prevented the leak from being predicted. These

four areas are summarized below. The full text is contained in Section 4.0 of RPP-ASMT-

57582, Second Workshop of the High Level Waste Integrity Assessment Panel: Extent of

Condition and Balance of Program.

Difficulty of Inspection

• No nondestructive evaluation (NDE) inspection data for tank bottom.

• No visual evidence of the tank bottom.

Limited Corrosion and Chemistry Data

• Limited corrosion data for historical environments.

• Limited corrosion data on welds and heat affected zones.

• Waste chemistry uncertainties. The heterogeneous nature of tank waste creates

uncertainties and difficulties in understanding and controlling internal corrosion.

• Limited chemistry data from bottom layer of sludge.

• Uncertainty related to chemistry controls.

Aging and Degradation Conditions Not Fully Considered

• Significant ventilation downtime leading to wet thermal insulation under the tank.

• Water intrusion in the annulus leading to humid environment.

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1-4

• Stress and thermal cycling.

• Impact of stresses on pre-existing weld defects on tank bottom.

Fabrication Conditions Not Fully Considered

• Condition of the refractory.

• Weld rejection rate.

• Post-weld heat treatment (PWHT) issues.

• Lack of nondestructive evaluation after PWHT.

1.2.2 Possible Degradation Mechanisms in Tank AY-102

The Panel ranked the following degradation mechanisms in order of likelihood (1 being the most

likely and 8 being the least likely) for being at the metallurgical cause of the Tank AY-102 leak:

1. Primary tank external corrosion (general or pitting)

2. Pitting corrosion from tank inside, waste chemistry induced

3. Nitrate-induced stress corrosion cracking (SCC) from tank inside

4. Corrosion under insulation (CUI) that is halogen-specific–induced heavy pitting on tank

external side (outside) of the primary tank bottom

5. Opening of pre-existing through-wall weld defect

6. Carbonate-induced SCC from tank inside

7. Corrosion-Fatigue; Fatigue crack growth

8. Caustic-induced SCC from tank inside

1.2.3 Specific High-Level Waste Integrity Assessment Panel Recommendations

The HIAP recommendations are provided in RPP-ASMT-57582 and are repeated below.

Data Analysis and Interpretation Activities

• Review tank chemistry history. The investigation into Tank AY-102 leak revealed a

much more complex history of waste transfers, chemistry, and in-tank waste mixing than

was previously appreciated. Based on the aforementioned risk ranking, the program

should investigate the detailed history of tanks with a higher potential for leaks. In

addition to potentially identifying previously overlooked troublesome chemistries in the

tanks, such analysis will also allow for a better understanding of the uncertainty

associated with a tank’s chemistry history.

• Rank tank leak risks. The Tank AY-102 leak caused a reevaluation of the DST

Integrity Program that includes the scope of this Panel. In this reevaluation, the factors

outlined in Section 4.0 of this report provide insight into potential clues to future tank

leaks. Using existing data, WRPS should perform a risk analysis to assess which tanks

are most likely to leak. This, in conjunction with the analysis presented in Appendix A,

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can be used to inform program priorities in allocating resources for integrity activities to

at-risk tanks and those that are most important to the mission.

Initially, the HIAP sees the following information as particularly important in judging a

tank’s likelihood of leaking:

1. Temperature during PWHT: This factor affects SCC and therefore is an

important consideration as it could lead to a large leak.

2. Weld rejection rate: This factor is also important as it affects SCC.

3. Liner bulging: Liner bulges during construction can affect SCC by

producing large residual stresses.

4. Maximum waste temperature and temperature cycling: This factor affects

both pitting and SCC.

5. Out of specification chemistry: This factor affects both pitting and SCC.

6. Years of service: This factor affects both pitting and SCC.

7. Operational period without active ventilation: Operation without the

annulus air ventilation may lead to thinning of the outside surface of the

primary tank.

Review and validate DST integrity program drivers. During the Panel’s review, it

emerged that the DST integrity program is governed by a number of drivers (e.g.

chemistry models, waste compatibility assessment process and caustic limits) that have

developed and evolved over the course of the program’s history (since 1994). The Panel

recommends the program review these drivers to validate that they are based on current,

valid programmatic needs.

Improved Data Gathering Activities

• Perform augmented inspections. A key to improving the leak prediction ability of the

program is increased collection of data indicative of conditions that could lead to a leak.

In these recommendations, HIAP emphasizes the importance of improving the ability to

collect data on the condition of both the primary tank and secondary liner.

Considerations should be given to:

Increase visual observations in the annulus. A goal of developing a 100% baseline of

visual observations in the annulus of all DST’s should be adopted. Specific to Tank AY-

102, WRPS should increase its frequency of visual observations, particularly at Riser 83,

to as frequent as is practicable. If multiple images can be obtained per hour or per day,

this should be considered.

• Perform visual and NDE observations of the primary tank bottom. Techniques to

provide observational data for the external surface of the primary tank liner steel,

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refractory and foam of Tank AY-102 should be investigated. These techniques can then

be transferred to investigate the state of other priority DSTs.

The air slots in the refractory provide an opportunity to access the bottom of the primary

tank. Robotic technologies should be pursued that, at a minimum, can enter air slots to

the initial 90o

turn, and provide visual evidence of the condition of the external surface of

the primary tank. Ideally, these technologies could turn multiple corners to access the

center of the tank. This may require widening of air slots, which, as long as it does not

impact structural integrity, would be acceptable.

The Panel was briefed on RolaTubeTM technology that can deploy visual and

Electromagnetic Acoustic Transducer (EMAT) technology through the air

ventilation slots. This appears to be a promising technology and should be pursued

to improve inspection of the primary tank.

Perform ultrasonic testing (UT) of secondary liner bottom in the annulus. The

annulus provides access to the secondary liner bottom and, as such, is an area where UT

data could provide some insight into the state of the condition of the secondary liner.

Optimize use of thermocouples. Tank AY-102 fortunately still has a number of reliable

thermocouples that could potentially provide early notification of a leak. WRPS should

consider deploying technologies that can utilize the existing thermocouples to provide

real-time readings and tracking of anomalies. A sudden, minor change in temperature

could be indicative of a leak.

Improve Continuous Air Monitors (CAMs). The current sample collection point for

the CAMs is in the main duct of the annulus exhaust. In this location, the CAM airborne

detection threshold has proven too high to detect small primary tank leaks. WRPS should

explore altering the sample collection point (e.g. near the annulus floor and other

locations around the annulus perimeter) to again utilize the CAM network as a viable tool

for DST leak detection.

Enhancing Existing Tank Integrity Program Elements to Prevent or Minimize

Degradation of the Double-Shell Tanks

• Perform corrosion tests on the secondary Tank AY-102 and leak detection pit (LDP)

steels at waste-specific and materials-specific conditions in aqueous and vapor

conditions. The Expert Panel Oversight Committee (EPOC) has provided

recommendations on testing of Tank AY-102 (RPP-ASMT-54634, Propensity for

Corrosion in 241-AY-02 Annulus, and RPP-ASMT-55871, Propensity for Corrosion in

241-AY-02 Annulus) and this testing should be performed.

• Ensure low humidity between primary tank and secondary liner. The ventilation

system should be continually operated to prevent moisture collection that could lead to

corrosion. Additionally, WRPS should consider purging the annulus with nitrogen as a

means of drying the potentially wet foam insulation. The presence of nitrogen also has

the potential to reduce the corrosion rate of the steel.

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• Perform additional sampling and analysis of sludge at the primary tank bottom.

WRPS should obtain improved data on the nature of the bottom sludge layer that is in

contact with the Tank AY-102 primary tank steel.

1.2.4 Supplemental Panel Recommendations From August Meeting

The supplemental HIAP recommendations from the August meeting documented in RPP-ASMT-

59980 are repeated below.

Rank tank leak risks - WRPS should consider adding a ‘consequences’ evaluation to the

risk ranking. The programmatic, environmental and/or worker health and safety

consequences of a DSTs leak could vary significantly depending on the waste contents

and programmatic importance (e.g. evaporator feed tank).

Perform augmented inspections - The visual and NDE inspection are a high priority for

the Panel. The augmented visual inspections (weekly visual monitoring of 241-AY-102

leak sites, monthly visual monitoring of 95% of the annulus space, increasing the

monitoring frequency for all DST’s from five to three years with visual coverage of 95%)

– are all examples of integrity activities that are responsive to this recommendation.

Ensure Low humidity between primary and secondary tanks – WRPS has been

responsive to this recommendation by continuing operation of the ventilation system.

WRPS should consider utilizing nitrogen tanker trucks to provide the purge gas. This

approach is used efficiently and effectively at many chemical plants and refineries.

Calculate flaw size - Leak rate estimates were presented to the Panel for the three areas

in the annulus where leaked Tank 241-AY-102 waste is located. The Panel recommends

WRPS estimate the flaw size based on these leak estimates. The Panel does not view this

a lengthy or expensive endeavor.

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2.0 SUMMARY OF PROGRAM IMPROVEMENTS

The proposed actions which addressed the HIAP recommendations (see Figure 1-2) have been

developed conceptually in Section 3.0, Section 4.0, and Section 5.0 with approximate schedules.

Figure 2-1 provides a summary of the task priorities discussed in Section 6.0. The post-retrieval

forensic recommendations identified in the August 2014 meeting are documented in RPP-

ASMT-59980, High Level Integrity Assessment Plan Workshop Summary.

Figure 2-1. Double-Shell Tank Integrity Task Priorities

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3-1

3.0 DATA ANALYSIS AND INTERPRETATION ACTIVITIES

3.1 REVIEW TANK CHEMISTRY HISTORY

3.1.1 Document Tank Chemistry History

The panel recommendation on tank chemistry history is provided in the sections below with the

WRPS response and schedule.

Panel Recommendation

The HIAP recommended in RPP-ASMT-57582:

The investigation into the Tank 241-AY-102 leak revealed a much more complex history

of waste transfers, chemistry and in-tank waste mixing than was previously appreciated.

Based on the aforementioned risk ranking, the program should investigate the detailed

history of tanks with a higher potential for leaks. In addition to potentially identifying

previously overlooked troublesome chemistries in the tanks, such analysis will also allow

for a better understanding of the uncertainty associated with a tank’s chemistry history.

Response/Scope

A review of the chemical history of Tanks AY-102 and AY-101 has been initiated in FY-2014 to

identify periods in time when the waste in these tanks was not in compliance with the current

chemistry specifications, in OSD-T-151-00007, Rev 12, Operating Specifications for the

Double-Shell Storage Tank (OSD), Table 1.5.1 potentially putting the integrity of the tanks at

risk. A template has been designed to present this information that can be used for the analysis

of the other high-risk tanks. The high risk tanks for future reviews include Tanks AY-101,

AY-102, SY-101, SY-103, AW-101, AW-104, and AP-102.

Schedule

High-risk tank chemistry histories will be reviewed and documented in a written report. Starting

in FY 2016 and continuing through for the next three years as shown in Figure 3-1.

Figure 3-1. Schedule to Review Tank Chemistry History

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Develope Template

at $150,000 per tank $300,000 $450,000 $300,000

3.1.1 Develop Template Based

on AY-102

FY 16 FY17 FY18 FY19

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3.2 RANK TANK LEAK RISKS

The HIAP recommendation regarding tanks risk was:

Rank tank leak risks. The Tank 241-AY-102 leak caused a reevaluation of the DST

Integrity Program that includes the scope of this Panel. In this reevaluation, the factors

outlined in Section 4.0 of this report provide insight into potential clues to future tank

leaks. Using existing data, WRPS should perform a risk analysis to assess which tanks

are most likely to leak. This, in conjunction with the analysis presented in Attachment 1,

can be used to inform program priorities in allocating resources for integrity activities to

at-risk tanks and those that are most important to the mission.

Initially, the Panel sees the following information as particularly important in judging a

tank’s likelihood of leaking:

1. Temperature during PWHT: This factor affects SCC and therefore is an important

consideration as it could lead to a large leak.

2. Weld rejection rate: This factor is also important as it affects SCC.

3. Liner bulging: Liner bulges during construction can affect SCC by producing large

residual stresses.

4. Maximum waste temperature and temperature cycling: This factor affects both

pitting and SCC.

5. Out of specification chemistry: This factor affects both pitting and SCC.

6. Years of service: This factor affects both pitting and SCC.

7. Operational period without active ventilation: Operation without the annulus air

ventilation may lead to thinning of the outside surface of the primary tank.

This comment resulted in three responses; the first was to develop a qualitative risk ranking that

can be used to weight all of the factors which could influence tank integrity to arrive at a

subjective risk ranking (discussed in Section 3.2.1).

The second step will be to rank the tanks with a more formal assessment, such as a Monte Carlo

analysis, based on the existing UT data from the tank walls (discussed in Section 3.2.2).

The third would be would expand results from the UT wall data to include results from the

bottom plate along with any other relevant factors in a formal risk assessment (discussed in

Section 3.2.3).

3.2.1 Qualitative Risk Ranking for All Double-Shell Tanks


The HIAP recommendation regarding tanks risk was:

Using existing data, WRPS should perform a risk analysis to assess which tanks are most

likely to leak. This, in conjunction with the analysis presented in Attachment 1, can be

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used to inform program priorities in allocating resources for integrity activities to at-risk

tanks and those that are most important to the mission.

WRPS should consider adding a ‘consequences’ evaluation to the risk ranking. The

programmatic, environmental and/or worker health and safety consequences of a DSTs

leak could vary significantly depending on the waste contents and programmatic

importance (e.g. evaporator feed tank). (from RPP-ASMT-59980)

Response/Scope

The qualitative risk ranking is attached in Appendix A. It cannot be used to “predict” failures. It

is merely a ranking based on potential factors that may influence operating life. This ranking

will be updated when the forensic activities for Tank AY-102 yield information on the cause of

the bottom plate failure. The weights have been provided by WRPS personal in Tank and

Pipeline Integrity.

Risk ranking criteria are the logical categories of influence provided by HIAP. The measures

were developed from available data on the 28 DSTs. These data points were quantified and

referenced back to source documents to the extent possible.

For each of the evaluation criteria, multiple measures have been developed to help evaluate their

respective criterion and to act as discriminators for making comparisons between alternatives.

Data for each tank is provided and referenced. The scoring is structured so that the tanks can be

discriminated according to performance differences in risk; higher scores represent higher risk.

The performance measures are described in Appendix A. Consequences will be considered in a

future revision

Schedule

This simplified version of the risk ranking would be maintained current with newly developed

data in FY 2016 and FY 2017 until it is replaced with a more formal assessment.

Figure 3-2. Schedule to Update Qualitative Risk Ranking for All Double-Shell Tanks

3.2.2 Risk Analysis Based on Sidewall Ultrasonic Testing Data

Panel Observation

The HIAP observed visual and UT inspection results of the 28 DSTs which, generally, showed

little primary tank wall corrosion. The inspection frequencies should be adjusted according to

the corrosion rates observed.

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Updating Risk Ranking $30,000 $20,000

3.2.1 Document Tank

Chemistry History

FY 16 FY17 FY17

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Response/Scope

This risk analysis provides a technical basis for adjusting the inspection frequencies based on the

results acquired to date.

The DST wall inspections cost about two million dollars per year at the frequencies shown in

Table 3-1.

Table 3-1. Double-Shell Tank Inspection Frequencies

Type Frequency Requirement from

Visual (video) Primary 5-7 years RPP-7574, Double-Shell Tank Integrity Program

Plan

Visual (video) Annulus 5-7 years RPP-7574, Double-Shell Tank Integrity Program

Plan

UT Primary Tank Wall from Annulus 8-10 years RPP-7574, Double-Shell Tank Integrity Program

Plan

A formal risk analysis would provide a technical basis for adjusting tank inspection frequencies

based on corrosion rates in individual tanks, and the other factors identified in the risk ranking.

The technical basis for reduced UT inspection frequencies of the primary walls of the DSTs

would be obtained by performing tank-specific analyses. Analyses would address all relevant

tank degradation mechanisms, tank operating history, field measurements, previous inspection

records, chemical constituents, and how these constituents may vary over time. Supporting

analyses would demonstrate that reducing inspection frequencies in the upper sidewall will not

compromise the continued safe operation and confirm that the likelihood of through-wall leak in

the tank sidewall is below acceptable thresholds over the tank anticipated service life.

Schedule

The evaluation would take 12 months to complete, as shown in Figure 3-3. Support from WRPS

would be required to provide the prior chemical analysis and UT wall inspection data.

Figure 3-3. Schedule for Frequency of Ultrasonic Wall Inspection

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Contract Bid/Award $10,000

Evaluation

WRPS Support/Review $10,000

External Review by

DNFSB and Regulators$50,000 $50,000

3.2.2 Risk Analysis Based

on Sidewall UT Data

FY 16 FY17

$200,000

$40,000

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3.2.3 Double-Shell Tank Risk Analysis Based on Bottom Plate Data

This activity would be undertaken with successful results from the risk analysis on the UT data

for the sidewalls. The former study would provide conclusions for the frequency of UT scans.

This formal risk analysis needs visual and UT data from inspection of the bottom plate to be

meaningful.

3.3 VALIDATE DOUBLE-SHELL TANK INTEGRITY PROGRAM

3.3.1 Primary Tank Chemistry Controls



Review and validate DST integrity program drivers. During the Panel’s review, it

emerged that the DST integrity program is governed by a number of drivers (e.g.

chemistry models, waste compatibility assessment process and caustic limits) that have

developed and evolved over the course of the program’s history (since 1994). The Panel

recommends the program review these drivers to validate that they are based on current,

valid programmatic needs.

The HIAP recommended chemistry models be reassessed in light of the unknowns of the bottom

sludge layer next to the surface of the primary tank bottom plate. The waste compatibility

assessment process and the caustic/nitrate/nitrite limits guiding the program should be revisited

once the chemistry at the bottom plate is known. This action applies to Tank AY-102 from a

forensic standpoint and to the rest of the tanks from the standpoint of maintaining chemistry

control.

Response/Scope

The current practice is to take data from stored core samples taken prior to 2006, document it in

RPP-7795, Technical Basis for the Chemistry Control Program, and determine if concentrations

fit within the current corrosion specifications. Process temperatures from the highest

temperatures in the tank waste are used to determine compliance with the OSD specifications.

No attempts to model old interstitial liquid (ISL) data in current, future compositions, or

temperatures are routinely performed. Some long term modeling is performed by subcontractors

with a finite element analysis.

The following key programmatic drivers that govern chemistry shall be reviewed by the HIAP:

• OSD-T-151-00007, Operating Specifications for the Double-Shell Storage Tanks,

• RPP-7795, Technical Basis for the Chemistry Control Program,

• RPP-13639, Caustic Limits Report,

• RPP-8974, Chemistry Control Program Calculation Methodology for Prediction of

Hydroxide Depletion in Double-Shell Tanks.

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Schedule

Updates to the chemistry modeling are part of the current program which occur on an ongoing

basis and are currently funded in the baseline. In addition, the EPOC will be funded for the

oversight and review functions of the programmatic drivers and address any shortcomings found

in FY-2016 through 2016 as shown in Figure 3-4.

Figure 3-4. EPOC Oversight of Tank Chemistry Controls

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

SRNL Lab Support

DNV Lab Support

222-S Lab Support

$600,000 $600,000

$1,000,000

$700,000

$600,000

$1,000,000

$700,000

$1,000,000

$700,000

3.3.1 EPOC Oversight of

Tank Chemistry Controls

FY 16 FY17 FY18 FY19

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4.0 IMPROVED DATA GATHERING ACTIVITIES

4.1 PERFORM AUGMENTED WALL SCANNING INSPECTIONS

4.1.1 Develop Electromagnetic Acoustic Transducer and Phased Array

WRPS currently utilizes a P-Scan UT system to perform NDE of the primary tank walls for the

Hanford Site DSTs. The P-Scan system returns high resolution measurements of material

defects (thinning, pitting, cracking), but with a very slow rate of material interrogation. Due to

this slow material interrogation rate, only a small percentage of the tank wall is inspected.




visual observations in all DST annuli should be adopted. Specific to Tank 241-AY-102,

WRPS should increase it’s frequency of visual observations, particularly at Riser 83, to

as frequent as is practicable. If multiple images can be obtained per hour or per day, this

should be considered.

Response/Scope

To address the slow material interrogation rates and limited volume of material inspected, WRPS

has placed a contract in April of 2014 with the Pacific Northwest National Laboratory (PNNL) to

develop and test an integrated EMAT and Phased Array Ultrasonic Transducer (PAUT) system.

Benefits of the EMAT-PAUT system include an increased material interrogation rate and the

subsequent ability to inspect a greater volume of material per deployment. The integrated

EMAT-PAUT system will be deployed using the Force Institute AGS-2 magnetic crawler

chassis. The AGS-2 is currently used to deploy Hanford’s existing P-Scan UT system.

EMAT was successfully deployed into DST AP-102 during the first quarter of FY 2015 with

great results. Deployment operations lasted two days with ~1.5 shifts worth of data collection.

Total wall area interrogated in the first EMAT deployment covered ~1.3% of the entire primary

tank wall which is roughly the equivalent area covered using the P-Scan system during an entire

DST UT campaign (~2-3 months). Additional EMAT deployments into DSTs are currently

planned which will be supplemented with lab testing so that a fully matured implementation

strategy can be developed for the EMAT system within the scope of the DST NDE program.

WRPS has also procured a Force Institute P-Scan Stack system (Figure 4-1) and will be working

with PNNL to test and validate the technology as a means to accelerate primary tank wall weld

joint inspections. The goal is to merge EMAT and PAUT into one cohesive data collection

system mounted to a single Force Institute AGS-2 magnetic crawler (Figure 4-2). This crawler is

identical to current UT crawlers and will be deployed and operate in the same manner.

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4-2

Figure 4-1. Force Institute P-Scan Stack System

Figure 4-2. AGS-2 Magnetic Crawler

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4-3

Schedule

The following schedule (Figure 4-3) shows the work flow and time associated with each top

level task. Field testing of the integrated EMAT system is planned to be performed on each

subsequent DST following completion of traditional UT. Mockup testing in the lab will serve to

validate the detection capabilities of the system. The primary objective for supplementing in-

tank evaluations with mockup testing is to reduce the time required to fully implement EMAT

and PAUT into the DST integrity program.

Figure 4-3. Schedule for Electromagnetic Acoustic Transducer Scans and Phased Array

Ultrasonic Transducers

4.1.2 Evaluate Additional Nondestructive Examination (Flash Thermography)





WRPS should increase it’s frequency of visual observations, particularly at Riser 83, to

as frequent as is practicable. If multiple images can be obtained per hour or per day, this


Response/Scope

WRPS will further evaluate additional NDE to enhance the efficiency of the existing wall

scanning method to free-up limited resources for increase support on inspections of tank bottom

plates. Flash Thermography is the planned NDE technology under investigation.

The basic concept of Flash Thermography is that the illumination source induces a temperature

rise at the inspection surface, generally in the form of an impulse, or delta function (short

duration, high intensity pulse). Locations interrupting the flow of heat, such as porosity, will

tend to “insulate” the heat pulse at the surface, creating a thermal indication which can be read

with an infrared (IR) camera. Such indication helps to identify problem areas for further

inspection by UT and visual testing. Flash Thermography is able to detect degradation such as

corrosion, leaks, cracks, porosity, etc.

1Q 2Q 3Q 4Q

EMAT-PAUT DST Field Deployments $10,000 $10,000 $10,000 $10,000

Mockup Testing at PNNL $50,000 $50,000

EMAT-PAUT Engineering Evaluation $10,000

4.1.1 Develop Electromagnetic Acoustic

Transducer Scans and Phased Array

FY 16

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Schedule

The projected schedule (Figure 4-4) was provided by AREVA NP Inc. in 2012 and is based on

one (Flash Thermography) of the three proposed NDE methods. The work is tentative planned

for FY 2016.

Figure 4-4. Schedule for Flash Thermography

4.2 INCREASE VISUAL OBSERVATIONS IN THE ANNULUS

The current DST annulus visual inspection program performs enhanced visual inspections of all

28 DSTs on a three year cycle. This visual evidence shows that a three year inspection interval

as described by the enhanced annulus visual inspection plan may fail to give early warning of

additional newly developing leak sites. Currently, Tank AY-102 undergoes a much more

rigorous visual inspection practice which consists of enhanced visual inspection performance on

a monthly basis along with weekly entry into three additional risers (77, 83, and 87) to monitor

known leak accumulation sites. Performing an enhanced visual inspection consists of entering

eight to 12 risers, depending on the tank, to visually observe greater than 95% of the annulus

floor.

4.2.1 Automated Annulus Camera System

In April 2014, HIAP recommended increasing visual inspection frequency to performing

enhanced visual inspections annually on all 28 DSTs. If the recommendation is adopted by

WRPS, then it is evident the current visual inspection practice will need to be optimized in order

to perform the required number of inspections. An automated annulus camera system would

enable field work crews to complete all of the required visual inspections on schedule.





WRPS should increase its frequency of visual observations, particularly at Riser 83, to as

frequent as is practical. If multiple images can be obtained per hour or per day, this


1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

NDE SOW/Contract Development

NDE Evaluation/Requirements $30,000NDE Development and Tests

NDE Design and Procedure $100,000NDE Operation and Implementation

4.1.2 Evaluate Additional NDE (Flash

Thermography)

FY 17 FY18

70,000

$50,000

$70,000 $110,000

$200,000

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Response/Scope

An annulus video monitoring system would consist of permanently mounted cameras on selected

annulus risers and would function remotely, without an operator field presence, as an annulus

surveillance system. Each riser camera would perform a visual inspection automatically

according to a preprogrammed schedule. All of the recorded video would be wirelessly

transferred to a network drive allowing access to the video files for post processing and review.

At any time, a designated operator could take over manual control of a specific riser camera and

manipulate the view at will.

Each of the permanently mounted riser cameras would be a stand-alone unit with all feedback

and control equipment contained internally. Remote manual manipulation of the camera system

would be accomplished through the use of a graphical user interface developed specifically for

the DST annulus video camera system. The entire 28 DST annulus video camera system would

be unified on a wireless network enabling data transfer and control with remote access.

Conceptually, the physical form function of the installed system might look like in Figure 4-5.

Figure 4-5. Conceptual Design for the Annulus Video Monitoring System

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4-6

The DST annulus video camera system would significantly reduce the amount of time needed to

perform a visual inspection and the cost of operators. Additionally, the quality and uniformity of

each inspection video would be greatly enhanced, making the post processing and review

activities much more efficient, thus, directly reducing cost and schedule impacts. The possibility

exists to eliminate field work activities associated with inspection performance along with the

associated work package preparation and mobile camera system deployment.

Currently, WRPS is acquiring a custom built visual inspection platform referred to as the Mobile

Still Camera System. The purpose of the new system is to obtain high quality still shots from

within the primary tank space (Waste Group C tanks only). The mechanical function of the

permanently installed riser video cameras closely parallels the function of the Mobile Still

Camera System. The largest difference between the two systems is the control system used to

enable remote operability of the permanently installed riser cameras.

Schedule

The design and fabrication of such a system would be a significant undertaking and, therefore, a

market survey should be performed to gather further information. The survey and concept

review should include discussions within WRPS as well as with capable vendors who could

design and manufacture the automated annulus camera system.

Discussion with capable subcontractors should be able to obtain ROM schedule and costs for

design, prototype development, testing, and manufacturing of a field ready system. Once these

items are addressed, a mature render of the overall cost and schedule can be realized.

After design of a viable concept, the number of applications for each tank would be determined.

Greater than 95% coverage of the annulus floor would require 8-12 risers per tank. High risk

tanks may deserve full coverage but it may not be cost effect to install a full complement of

automated cameras on all 28 tanks. The work is tentatively planned for FY 2016. The schedule

is presented in Figure 4-6.

Figure 4-6. Schedule for a Premium Annulus Video Monitoring System

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Internal WRPS Survey & Concept Review $10,000Procurement

SOW Development

Contract Placement

$10,000

Equipment Development

Prototype Design/Test/Deliver

Work Planning

Operational Readiness Review$40,000

Field Work Prep

Prototype System Field Installation$200,000

WRPS internal engineering system

evaluation period$10,000

Incorporate design modification to field

prototype as needed$10,000

Build 20 additional units @ 25k each

Field Work Prep

Final System Field Installation

4.2.1 Automated Camera SystemFY 17 FY18

$700,000

$500,000

$1,100,000

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4.3 VISUAL OBSERVATION AND NDE OF THE PRIMARY TANK BOTTOM

4.3.1 Visual – Robotic Crawler in Air Slots




liner. Robotic technologies should pursue that, at minimum, can enter air slots to the

initial 90° turn, and provide visual evidence of the condition of the primary tank.

Response/Scope

Robotic visual inspection of the refractory air slots would be accomplished through the use of a

crawler deployed to the annulus floor. Document RPP-ASMT-55798, Alternatives Evaluation

for Tank 241-AY-102 Robotic Inspection, gives the basis for selection of Vista Engineering, now

Kurion, and a robotic solution to perform refractory air slot inspections (see Figure 4-7).

The key technical feature used in the Kurion concept is RolaTube technology. The RolaTube

and reel drive system used to deploy the camera into the refractory air slots. Deployment of the

Kurion concept would be accomplished via a 12 in. riser at grade to lower the platform down to

the annulus floor (see Figure 4-8).

Once on the annulus floor, the crawler would be

remotely oriented to be tangent to the refractory

pad. The RolaTube reel mechanism would be

rotated 90° to align with the refractory air slots

while magnets on the reel system would lock the

crawler in alignment with the refractory retaining

ring (see Figure 4-9).

Following orientation of the crawler on the

annulus floor the RolaTube is deployed into the

air slot. As the reel is extended through the first

12-foot straight section, the camera attached to

the end of the RolaTube will return live footage

of the refractory air slot (see Figure 4-10).

The camera head will incorporate a mirror to capture multiple views of the air slot without the

need to manipulate the orientation of the camera head itself.

Multiple air slots can be inspected with one deployment of the crawler. Using this inspection

system, visual data can be collected regarding:

• Condition of the refractory material towards the center bottom of the tank.

• Condition of the bottom of the primary tank.

Figure 4-7. Robotic Air Slot Visual

Inspection Crawler

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4-8

• Number of air slots blocked with leaked tank waste.

• Possible location of the primary tank leak.

Figure 4-8. Deployment Method of Crawler Concept

Figure 4-9. Crawler Oriented on

Annulus Floor and Aligned with Air

Slot

Figure 4-10. Camera Inserted into Refractory Air

Slot for Visual Inspection (note: Primary Tank

Hidden from View)

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4-9

Schedule

The schedule for this proposed action is summarized in Figure 4-11.

Figure 4-11. Schedule for the Robotic Air Slot Visual Inspection Crawler

4.3.2 Visual–Robotic Annulus Air Supply Pipe Inspections




liner. Robotic technologies should be pursued that, at a minimum, can enter air slots to

the initial 90o

turn, and provide visual evidence of the condition of the external surface of

the primary tank. Ideally, these technologies could turn multiple corners to access the

center of the tank.

The annulus air supply pipe provided access to the air plenum at the center of the tank.

Since the leak of Tank AY-102 was discovered, the exact location of the leak in the primary tank

still remains unknown. Leakage on the bottom plate of the primary tank is taking a path through

the refractory pad air slots. The air slots may allow the leak a path to travel with little restriction

to other areas of the tank. Currently, the theory of how the waste may be leaking and traveling

within the refractory pad air slots is only speculation. The objective of visual inspection

performance within the air supply piping is to substantiate the existing theory. Combining the

results of air supply piping robotic visual inspection and the refractory air slots (see Section

4.3.1) will give hard data to answer the following questions:

• How many slots are blocked by leaking waste?

• Where is the exact location of the primary tank leak site?

• What is the condition of the air supply piping?

• Is the central air distribution chamber full (blocked) with waste?

• What is the condition of the center bottom of the primary tank shell?

1Q 2Q 3Q 4Q

Procurement

SOW Development

Contract Placement

$10,000

Tooling Development

Kurion Design/Test/Deliver

Work Planning


Field Work Prep

Robotic Inspection$250,000

4.3.1 Visual - Kurion Robotic

Crawler in Air Slots

FY 16

$850,000

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4-10

• What are the temperature/humidity/flow conditions within the air supply piping?

Response/Scope

Robotic inspection of the ventilation header

would be performed with a scaled variant of the

IHI Southwest Technologies, Inc. (IHI) pipe

crawler that was previously used to perform the

visual inspection of the Tank AY-102 leak

detection pit. Details and results of that

inspection can be found in RPP-RPT-56464,

241-AY-102 Leak Detection Pit Drain Line

Inspection Report. The IHI pipe crawler utilizes

a chassis configuration that allows the robot to

travel through piping bends in addition to

straight sections of pipe (Figure 4-12). On the

front of the crawler chassis is a pan/tilt/zoom

camera head with a dimmable circular array of

light emitting diodes (LEDs).

An overview of Tank AY-102 ventilation air supply piping with relation to tank geometry is

shown in Figure 4-13. The headers travel around the tank circumferentially bellow grade. Color

has been applied to the piping to differentiate the supply and exhaust headers.

Figure 4-14 shows a stripped model of a DST, leaving only the air supply piping. Branching

from the header ring is four supply lines (Drop leg 1-4) which jointly supply air to the center

distribution chamber located centrally within the refractory layer.

Each 4 in. drop leg is cast within the refractory layer up to the central distribution chamber

interface.

Figure 4-12. Robotic Pipe Crawler

Figure 4-13. Ventilation Air Supply System

Overview

Figure 4-14. Air Supply Piping

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4-11

Upon entering the central air distribution chamber, the direction of flow reverses and travels

radially outward through the refractory air slots and into the annular space between the primary

tank and secondary liner. Upon reaching the annulus, the air is drawn up to each of the six

exhaust risers and evacuated from the system by the exhauster fan. Before the IHI pipe crawler is

deployed in the farm, excavation activities must be performed to expose the joints where the 4 in.

drop legs attach to the supply header ring.

Schedule

Two major portions of work are required to successfully accomplish this inspection. These work

scopes can proceed in parallel.

Ventilation air supply header modification includes:

• Fabrication of new risers for attachment to the existing vent header

• Excavation activities in the farm to expose vent header

• Weld in the farm to attach new risers

• Backfill new risers to grade

IHI custom robotic pipe crawler chassis for 4 in. Schedule 40 pipe includes:

• Prototype CAD design, fabrication, testing and rework

• Field ready crawler fabrication

• Field ready crawler factory acceptance testing

This Activity is prioritized to begin in FY-2017 as shown in the schedule presented in Figure

4-15.

Figure 4-15. Schedule for Robotic Annulus Air Supply Crawler

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Procurement

SOW Development

Contract Placement

$10,000

Tooling Development

IHI Southwest Design/Test/Deliver

ECN Development

Excavation Work Package Planning

Riser Cutting Work Package Development

Mock up Work Package

New Riser Stub Assembly fab Work Package

Robotic Inspection Work Package

On Site Mock up Demonstration $30,000Work Planning


Field Work Prep

Robotic Inspection$880,000

4.3.2 Visual - Robotic Annulus Air Supply Pipe

Inspections

$170,000

FY 18 FY19

$200,000

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4-12

4.3.3 Nondestructive Examination–Synthetic Aperture Focusing Technique and Tandem

Synthetic Aperture Focusing Technique


The HIAP recommended WRPS perform enhanced NDE to inspect the tank bottoms. The

implementation of advanced UT techniques at the tank bottom is to obtain quantitative data to

validate the structural integrity in the lower region of DST. The recommendation is in

RPP-ASMT-57582:

Visual and NDE observations of the primary tank bottom. Techniques to provide

observational data for the bottom steel, refractory and foam of Tank 241-AY-102 should

be investigated. These techniques can then be transferred to investigate the state of other

priority tanks.

Response/Scope

The existing Synthetic Aperture Focusing

Technique (SAFT) and Tandem Synthetic

Aperture Focusing Technique (T-SAFT) (Figure

4-16) will be deployed to perform the following:

1. Perform preliminary evaluation which

involves assembling existing inspection

hardware that is already owned by

WRPS to evaluate its current condition

and applicability for inspection of the

primary tank bottom.

2. Develop mockup to demonstrate the

revised capabilities of this T-SAFT

technique.

3. Provide limited detection but not dimensioning capability.

4. Assemble, test, and document the pros and cons of these techniques in conjunction with

normal ultrasonic inspection. The report will provide path forward recommendation as to

whether any or all of the existing systems could be utilized as an enhanced inspection

device for the primary tank bottoms.

Schedule

For PNNL to make further progress for redeployment and revalidation of the existing

SAFT/T-SAFT methods, the following schedule is given in Figure 4-17.

Figure 4-16. FORCE–Extended Arm and

Tandem Synthetic Aperture Focusing

Technique for Lower Knuckle Region

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4-13

Figure 4-17. Schedule for Ultrasonic Testing using Synthetic Aperture Focusing Technique

and Tandem Synthetic Aperture Focusing Technique

4.3.4 Nondestructive Examination - Robotic Crawler (Guided Wave in Air Slots)

The HIAP has recommended that WRPS to gather data specific to the bottom of the primary

tank. The majority of the proposed robotic inspections will return visual data of the primary tank

bottom. UT and/or guided wave UT scans of the lower primary tank plates would supplement

the visual inspection.


The HIAP recommended in Section 6.1 of RPP-ASMT-57582:

The Panel was briefed on RolaTube technology that can deploy visual and EMAT

technology through the air ventilation slots. This appears to be a promising technology

and should be pursued to improve inspection of the primary tank.

Response/Scope

To supplement the visual data there should be an effort made to gather data about the lower

primary tank liner, specifically; thinning, pitting, and cracking. A potential solution to gather

this kind of data resides in the annulus crawler used to perform the refractory air slot visual

inspection. The crawler chassis shown in Figure 4-7 might be modified to deploy UT or guided

wave UT sensor elements into the refractory air slots.

Conceptually the UT/guided wave UT sensory device would be mounted to the end of the

RolaTube and inserted into the refractor air slot to the desired depth and then temporarily affixed

to the bottom of the primary liner. If a guided wave UT material interrogation method is pursued

it will most likely require two crawlers to be deployed to the annulus floor and work in a parallel

effort.

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Procurement

SOW Development

Contract Placement

$40,000

Enhancement Development

PNNL Design/Test/Deliver

Work Planning


Field Work Prep

TSAFT In-Service Implementation$60,000

$120,000

4.3.3 UT - SAFT and T-SAFTFY 16 FY17

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4-14

Schedule

The following schedule is presented in Figure 4-18.

Figure 4-18. Schedule for the Robotic Multi-Air Slot Nondestructive Evaluation

4.3.5 Nondestructive Examination–Guided Wave System (Across Tank Diameter)


The HIAP recommended WRPS perform enhanced NDE to inspect the tank bottom. The

implementation of advanced UT techniques at the tank bottom is to obtain quantitative data to

validate the structural integrity in the lower region of DSTs.

Response/Scope

The Long Range Guided Wave Ultrasonic Testing (LRGWUT) (see Figure 4-19) is being

proposed as a method for evaluation of the primary tank bottom in two stages.

1. Research will be conducted to ascertain what has been performed in industry to identify

similar applications. The literature survey will provide a basis for further investigation

using similar techniques.

2. A small scale proof of principal test using guided wave equipment will be performed to

evaluate various guided wave-mode propagations. The test will be performed on plate

material representative of the type and thickness of the tank bottom used in the AY Tank

Farm to confirm useable acceptability of the application.

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Procurement

SOW Development

Contract Placement

$10,000

Tooling Development

Kurian Design/Test/Deliver

Work Planning

Operational Readiness Review 50,000Field Work Prep

Robotic Inspection $250,000

$850,000

FY 16 FY174.3.4 UT - Kurion Robotic

Crawler (Guided Wave in Air

Slots)

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4-15

Figure 4-19. Long Range Guided Wave Ultrasonic Testing

LRGWUT enables a large area of structure to be tested from a single transducer position thereby

avoiding the time-consuming scanning required by the conventional ultrasonic methods. This

technique becomes even more attractive if part of the structure to be tested is inaccessible. The

test is usually done in pulse-echo mode. The transducer is transmitting the guided wave along

the structure and returning echoes indicating the presence of defects or other structural features.

To demonstrate this technique, a 75 ft diameter DST carbon steel mockup with consistence tank

constructability and field conditions will be needed.

The LRGWUT method will be evaluated and the limitations are to be documented with a path

forward recommendation as to whether LRGWUT technology could be utilized as an inspection

device for the primary tank bottoms.

Schedule

The projected schedule references the basis for LRGWUT development and implementation as

shown in Figure 4-20.

Figure 4-20. Schedule for Inspection using Guided Wave Transducers

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Procurement

SOW Development

Contract Placement

$60,000

Enhancement Development

Design/Test/Deliver

Onsite Mock-Up Demonstration

(Guided-Waves)$250,000 $250,000

Field Work Prep

Guided Waves In-Service

Implementation$120,000

4.3.5 UT - Guided Wave System (Across

Tank Diameter)

FY18 FY19

$340,000

Transmitter Receiver

Volume Inspected

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4-16

4.4 PERFORM ULTRASONIC TESTING ON SECONDARY TANK BOTTOM IN

THE ANNULUS

4.4.1 Perform Ultrasonic Testing with Existing Procedure



The annulus provides access to the secondary tank bottom and, as such, is an area where

UT data could provide some insight into the state of the condition of the secondary tank

bottom.

Response/Scope

The existing wall scanning UT equipment can be used to scan the floor of the annulus. This

action is fairly straightforward and will be included in the scope of all future wall scans.

4.5 OPTIMIZE USE OF THERMOCOUPLES FOR EARLY LEAK NOTIFICATION

4.5.1 Use of Thermocouples to Detect Leaks



Tank 241-AY-102 fortunately still has a number of reliable thermocouples that could

potentially provide early notification of a leak. WRPS should consider deploying

technologies that can utilize the existing thermocouples to provide real-time readings and

tracking of anomalies. A sudden, minor change in temperature could be indicative of a

leak.

Response/Scope

This recommendation is not accepted. About half the thermocouples have failed and would not

be particularly useful in detecting a leak (Table 4-1). Normal temperatures from the

thermocouples that do exist would simply be a false positive indication that no leak had

occurred.

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4-17

Table 4-1. Tank AY-101 and Tank AY-102 Thermocouples Operable (8/2012)

Refractory AY-101 AY-102

7-ft ring 3 of 4 2 of 4

21-ft ring 8 of 8 4 of 8

36-ft ring 9 of 13 8 of 13

Base slab 0 of 9 4 of 9

Additionally, the variation in thermocouple temperatures is from the operation of the annulus

ventilation system. Outages and outside air temperature are primary drivers that would mask

leaks, presuming a leak did occur in the vicinity of an operable thermocouple.

4.6 IMPROVED CONTINOUS AIR MONITORING

4.6.1 Improved Annulus Air Monitoring Design

Each DST is equipped with a CAM. Each CAM unit draws and returns samples from its

respective tank annulus exhaust. The sampling and return ports on the duct are located upstream

of the filtration equipment. A vacuum pump at the CAM station pulls air from the annulus duct

into the CAM analyzer. If contamination is detected, a signal activates a local alarm light and

the alarm horn at the radiation-monitor station. Simultaneously, a signal is transmitted to the

respective control room, activating an annunciator on the monitor and control system and

energizing the alarm light on the human-machine interface monitors.

By design, each DST annulus ventilation exhaust CAM serves as a primary means of leak

detection. Through experience gained from Tank AY-102 leak observation, the only time the

annulus CAM alarms is when the waste accumulation on the annulus floor is disturbed. Annulus

Honeywell ENRAF-Nonius 854 (ENRAF) leak detectors in Tank AY-102 are proving

ineffective in that they are not in alarm despite waste clearly leaking into the annulus. Overall,

the extent of our DST design provides no effective detection capability for small and slow leaks

such as the one observed in Tank AY-102.

A possible cause for the CAM problem could be that the reduction of velocity when the annulus

air exits the air slots under the primary tank is too great to maintain radioactive particulate

suspension in the annulus chamber, and carry the contamination to the top of the annulus into the

exhaust ductwork where it would be sampled, triggering an alarm.

Some initial work has been done to understand the flow phenomenon through the annulus

ventilation system, utilizing mass flow rate balancing to determine the reduction of velocity

experienced transitioning from the air slot to the complete annulus cross section. Estimates of

the air velocity transition from the refractory air slots to the annulus are 18.6 ft/sec to

0.034 ft/sec. This significant reduction in flow velocity is of interest in that it helps to

understand the ventilation systems ability to uplift airborne radionuclide particles into the

exhaust system flow with enough reliability to consistently detect a small and slow leak.

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4-18

More complicated modeling of particle-laden air flow would be required to determine the extent

to which particles can be entrained in the ventilation system flow and travel to the CAM unit,

located just before the on-grade exhaust system.



CAMs in the DST system have historically been used as a leak detection mechanism.

However, in recent years, the CAMs have not been sufficiently reliable to be useful in this

application. WRPS should explore improving the design of the CAMs to again utilize the

network as a tool for detecting leaks

Response/Scope

Improvements to the system have been identified to address current detection limitations. Since

these limitations generally stem from the CAM system sampling location and the ability to

reliably deliver annulus radionuclide particles to it through the exhaust system, any modification

to the system to achieve more reliable particle detection will reduce the resistance between

potential leak sites and the CAM sampling system. With this criteria in mind, the following

subset of improvement possibilities have been identified:

Option 1: Improve Continuous Air Monitoring System

To improve the current CAM system, modifications to the exhaust risers and CAM sample

locations would be required. Problems with the current system likely relate to inadequate

particle entrainment in flow and friction losses in the exhaust header through the flow path. That

is to say that radioactive particles cannot be confidently uplifted by the reduced annulus

ventilation velocity to the riser penetration and upon entry into the system, inherent friction

within the extensive exhaust header presents resistance to flow that may hinder collection of

particles on the upstream CAM system.

Current exhaust risers penetrate the top of the annulus space where a cross-sectional area

increase in the annulus space causes a significant velocity reduction. Mitigation of this reduction

in velocity could be accomplished by extending the source of vacuum further down toward the

bottom of the annulus space with an extended exhaust riser. An extension of these risers would

serve to reduce the distance which entrained particles travel.

In addition to modifications to the riser penetration, CAM units could be collocated in-line with a

number of existing exhaust riser penetrations to limit the length of pipe travel from a leak site to

a detection method. This modification would function just as the existing system does, but with

more sampling points located closer to the sources to improve detection capability.

While the scope of improved air monitoring throughout the DST system and number of CAM

units required for each tank are items requiring further engineering evaluation, the advantages of

an effective continuous monitoring system as a primary means of leak detection cannot be

overstated. With the current absence of slow and small leak detection capability via existing

CAMs or automated level indicators, the existing manual, visual inspection program has

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4-19

expanded to function in leak detection and monitoring capacity. Any improvements to the

automated and continuous monitoring solutions for leak detection to achieve reliable

functionality would serve to alleviate the significant operational burden related to the growing

scope of the manual, visual inspection program.

Option 2: Develop a Riser Deployable Air Monitoring System

While a reliable and automated CAM system as described in Option 1 is the most desirable

improvement methodology, provisions could be made to deploy a more modular air monitoring

system. This system would be a self-contained, annulus riser mounted assembly. Generally

speaking, it would provide its own source of vacuum and recirculate flow back through the same

riser. Within the closed loop system, a filter would be raised and lowered into the annulus space

to variable depth allowing manual control of sample location and duration.

Upon filter return to the riser mounted assembly, radiological monitoring of the paper would

occur to trend contamination presence in the annulus space on an engineering defined

periodicity. This system could operate in a manual and/or automated fashion. It is conceivable

that these two options could be integrated into one cohesive system for annulus inspection.

Schedule

This work is deferred to FY 2018. The schedule is summarized in Figure 4-21.

Figure 4-21. Schedule for Improved Annulus Air Monitoring Design

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Engineering Evaluation of Improvement

Scope$10,000

Evaluation Options for Improvement and

Conclude

Mockup/Prototype Development $50,000

Test Chosen Concept $50,000

Update Concept Based on Test Results $20,000

4.6.1 Improved Annulus Air Monitoring

Design

FY 18 FY19

$100,000

$100,000

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5-1

5.0 ENHANCED EXISTING INTEGRITY PROGRAM TO MINIMIZE

DOUBLE-SHELL TANK DEGRADATION

5.1 CORROSION TEST SECONDARY LINER AND LEAK DETECTION PIT STEEL

FOR TANK AY-102

5.1.1 2014 Corrosion Work on Tank AY-102 Steel



Corrosion test the secondary Tank 241-AY-102 and Leak Detection Pit steels at waste-

specific and materials-specific conditions in aqueous and vapor conditions. The EPOC

has provided recommendations on testing of Tank-AY-102 (RPP-ASMT-54634 and RPP-

ASMT-55871) and this testing should continue to be performed.

Response/Scope

This recommendation is being resolved with work currently ongoing and is being reviewed by

the EPOC.

5.2 ENSURE LOW HUMIDITY BETWEEN PRIMARY AND SECONDARY LINERS

5.2.1 Dehumidifiers on Annulus Air Inlet



Ensure low humidity between primary and secondary tanks. The ventilation system

should be continually operated to prevent moisture collection that could lead to

corrosion. Additionally, WRPS should consider purging the annulus with nitrogen as a

means of drying the potentially wet foam insulation. The presence of nitrogen also has

the potential to reduce the corrosion rate of the steel.

WRPS should consider utilizing nitrogen tanker trucks to provide the purge gas. This

approach is used efficiently and effectively at many chemical plants and refineries. (from

RPP-ASMT-59980)

Water vapor in the humid ambient air is drawn into the ventilation piping and may be creating a

moist environment in the annular space of the DSTs, which may result in corrosion of the

primary tank bottom or secondary liner. It was recommended by the HIAP to achieve low

humidity between the primary tank and secondary liner. Reducing the water vapor in the air

used to ventilate the annular space of the DSTs reduces the propensity for corrosion on the

bottom of the primary tank and secondary liner.

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5-2

Response/Scope

DSTs contain radioactive sludge that is

thermally hot because of heat generated by the

decay of radioactive elements. The heat makes

it necessary to cool primary tanks utilizing air

slots beneath the primary tank bottom which

exhaust into the annulus.

An exhauster is used to pull air through four

ventilation pipes (241-AW, AN, and AP Farm

tanks all have eight ventilations pipes, all other

tanks use four) which enter the annulus through

risers. The ventilation piping runs down the

secondary liner wall and across the secondary

liner bottom to the center of the tank and is

embedded in the refractory. The ventilation

piping ends at an air distribution ring at the

center of the tank. From the air distribution

ring, the air flows through the air slots in the

refractory and out to the annulus where it is

routed out of the annulus to the exhauster (see

Figure 5-1).

A dehumidifier can be used to reduce the

water vapor found in humid ambient air by

condensing the water vapor. Atmospheric air

enters a chiller condenser, which cools the air

down to the dew point to allow water vapor to

condense and dry air leaves the system.

Heaters are used prior to the discharge during

cooler temperatures. Desiccants are

sometimes used as a pre-treatment to reduce

the amount of cooling that needs to take place.

Dehumidifiers are commonly used in industry

and portable industrial humidifiers are readily

available in pre-built packages.

A silica gel desiccant can also be used to

dehumidify the air. The desiccant works by

attracting the moisture in the air to stick to it.

Some of these systems reactivate the desiccant

by heating it to drive off the moisture. These

desiccants can last up to 20 years. Desiccant

systems can be used in tandem with the chiller

condenser unit to further reduce the relative

humidity.

Figure 5-1. Proposed Dehumidifier

Layout

Figure 5-2. Portable Industrial

Dehumidifier with Condenser Reheat

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5-3

A single dehumidifier can be purchased for each DST farm. A manifold can be used to connect

the dehumidifier to the air inlet for each tank in the farm. See Figure 5-2 for an example of a

commercial dehumidifier.

Schedule

Design:

Design of the dehumidification system involves determining the best placement of

dehumidification equipment including a dehumidifier and ductwork. Drawing modifications,

new drawings, calculations, specifications, electrical flash, and arc flash are also part of the

design process. Calculations for dome loading, structural analysis, ducting supports, ventilation

duct loss, and seismic analysis are necessary.

Dehumidifier Procurement:

There are two main ways to dehumidify air. The first method is to use a chiller condenser

(refrigeration unit) to remove water vapor from the air and reduce the relative humidity. The

other method is to use silica desiccants, which draw moisture out of the air. These two systems

can be used in tandem to reduce the relative humidity even more. It is not currently known how

low the relative humidity should be to reduce any possible corrosion. Therefore, at this time

only the refrigeration dehumidification unit is considered.

Develop Test Plan and Test Dehumidifier:

There are several sets of tests that may need to be conducted on the system prior to operation.

There are two categories which govern the testing of equipment. They are as follows:

• Factory acceptance test (FAT)

• Operation acceptance test (OAT)

The FAT is conducted directly after receipt of the equipment from the factory. Each part of the

system is tested to determine that it meets factory specifications and tolerances. The OATs are

usually the same as the FATs. However, OATs are completed after the equipment is moved into

the field and prior to operation of the equipment. These tests are to ensure that nothing was

damaged during transportation and placement in the field. FATs and OATs require the

development of a test plan, sub-test plan, and a test requirement matrix.

Field Installation and Connecting Dehumidifier:

The placement of the dehumidifier will require the use of a crane and rigging crew along with

other support personnel required for entry into a tank farm. It will require the determination of

exclusion zones and access points within the tank farm. The dehumidifier shall be placed on a

concrete base pad. Excavation and digging permits may be required to place the base.

Connecting the dehumidifier includes running ducting to the tanks. All ducting is to be run from

the dehumidifier to the annulus air inlets for each tank. Ducting can be run below grade or above

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5-4

grade. Ducting routed above grade runs the risk of cutting off access points and crane routes

within the tank farm. Running ducting below grade requires digging permits, and extensive

radiological surveillance.

Assuming 150 ft of ducting, this activity includes digging, placing the ductwork, and back filling

requirements.

This work is deferred to FY 2018. Schedule durations are shown in Figure 5-3.

Figure 5-3. Schedule for Annulus Air Humidity Control

5.3 SAMPLING AND ANALYSIS OF SLUDGE AT THE BOTTOM PLATE

5.3.1 Core Sample Tank AY-102 at Bottom Plate

This activity was deleted to avoid delays in Tank AY-102 retrieval.

5.3.2 Analyze Sample (Corrosion Testing)

This activity, analysis of the AY-102 sample, was deleted to avoid delays in Tank AY-102

retrieval.

5.3.3 Sample AY-102 Annulus with Robotic Crawler

Although remote sampling of leaked tank waste in the annulus of Tank AY-102 has been

successfully performed in past events, WRPS currently has no remote capability to obtain

new/additional samples from the annular space of a DST. Forgoing the opportunity to get a

primary tank bottom sample in Tank AY-102, shifts the annulus sampling activity to a higher

priority. Maintaining remote annulus sampling capability assures that in an emergent situation

the equipment is on the shelf and capable of performing the work. Currently there is need of

additional samples which will be used to perform corrosion testing. Acquisition of the much

needed sample material is contingent on WRPS obtaining a remote sampling technology

designed specifically for the annular space of the DSTs.


The HIAP recommended obtaining a better sample from the accumulating material in the

annulus of Tank AY-102. This was once attempted with little success. With a better

understanding of the material in the annulus, a potential cause of the leak may be determined.

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

Design

Procure Dehumidifier

Develop Test Plan

Test Dehumidifier $20,000

Place Dehumidifier $50,000

Connect Dehumidifier to Tank $30,000

5.2.1 Dehumidifiers on Annulus

Air Inlet

FY 18 FY19

$300,000

$90,000

$10,000

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5-5

This activity becomes a priority in the absence of taking a sample near the bottom of the primary

tank.

Response/Scope

WRPS should perform a market survey of

capable vendors who can provide the necessary

equipment to perform remote sampling

activities in the annular space of the DSTs. The

study should begin by reviewing previously

used annulus sampling equipment and then

utilize lessons learned to develop an optimized

remote sampling platform designed specifically

for the DST annulus environment. Previously

used annulus sampling equipment can be seen in

Figure 5-4 and Figure 5-5. The market survey

should conclude by designating a vendor

capable of procuring a remote annulus sampling

platform optimized for the DST annulus

environment.

The off riser sampling system (ORSS) was

originally used to scoop solid samples from the

floor of SSTs following retrieval activities. The

ORSS was deployed through Riser 91 of Tank

AY-102 on September 26, 2012 to sample the

leaked waste accumulation site near Riser 83.

Sampling efforts were successful but not

without challenges which could be overcome

had the ORSS been designed specifically for

annulus sampling missions.

The remote underground sampler (RUS) was

developed by AREVA as a remote underground

sampler designed to collect potentially hard

material. Sampling of material near Riser 90 of

Tank AY-102 occurred on October 15 and 17,

2012. Mounted to the front of the crawler was

an auger bit in a sleeve with a scoop underneath that could dump sampled material into a

container.

Following the final report’s recommendation, the selected technology vendor would be

contracted to develop, procure, and test the remote sampling technology. After the technology is

proven lab capable of deployment into the field, the system will be deployed into the annular

space of Tank AY-102 to collect additional samples of the leaked tank waste so that corrosion

testing can be performed with actual materials as opposed to simulants.

Figure 5-4. Washington River Protection

Solutions Off Riser Sampling System

Figure 5-5. AREVA Remote Underground

Sampler

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5-6

Schedule

The following schedule shows the work flow and time associated with each top level task

(Figure 5-6). The subject scope of the document would include: a recommendation for the

optimal remote annulus sampling system, a system design description, implementation strategy,

and recommended path forward.

Figure 5-6. Schedule for Robotic Annulus Sampling

1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q

WRPS Engineering Concept Development $7,000

RFP Placed $40,000

Review of Proposal(s) $3,000

Develop RPP

Develop SOW/Place Contract $40,000

Procure Remote Annulus Sampling System

Work Planning/Operational Readiness Review $50,000

Field Work Preparation/Remote Sampling Performed

5.3.3 Sample Annulus with Robotic CrawlerFY 16 FY17

$10,000

$100,000

$250,000

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6-1

6.0 CONCLUSIONS AND PATH FORWARD

In the August 2014 meeting with the HIAP, an out brief was provided with their

recommendations. The most important areas for future work are 1) the condition of the top and

bottom surfaces of the primary tank, and 2) the viability of the secondary liner. The actions that

logically flow from these priorities are:

1. Visual inspection of the annulus air slots and air supply lines.

2. Measuring the primary bottom plate thickness.

3. Waste samples from a core in the primary tank at the surface of the bottom plate and the

leaked material on the floor of the annulus.

4. Corrosion testing.

With these priorities and recommendations, the path forward has been established for each of the

project actions as summarized in Table 6-1. The task priorities are defined as follows:

1a. Ongoing work from existing budgets in FY 2015 and/or FY 2016.

1b. Deploy in FY 2016 via Budget Change Request (BCR).

1c. Develop the technology in FY 2016 via BCR.

2. Second priority candidates for further develop and funding in FY 2017.

3. Third priority activities deferred to FY 2018 or later.

Table 6-1. Double-Shell Tank Integrity Task Priorities and Path Forward (3 Pages)

Task Priority Description of Path Forward

3.1.1 Document Tank

Chemistry History

1b A template has been established and work has been initiated for

Tanks AY-101, AY-102, AN-102 and AN-107. The remaining

tanks will be completed within the scope of the Base Operations

Process Engineering and the results will be integrated into the

Qualitative Risk Analysis.

3.2.1 Qualitative Risk

Ranking for All DSTs

1b An initial risk ranking has been completed and included in

Appendix A. This evaluation will be maintained current with

results from Task 3.1.1 and related performance measure

additions or changes.

3.2.2 Risk Analysis Based

on Sidewall UT Data

1b The sidewall UT data will be evaluated formally as a bases to

adjust the frequency of the inspections.

3.2.3 DST Risk Analysis

Based on Bottom Plate

Data

3 This work depends on future bottom plate measurements which

will not be available for several years.

3.3.1 Primary Tank

Chemistry Controls

1b The EPOC will be engaged in an overview of chemistry control

program as funding is available.

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6-2



4.1.1 Develop EMAT and

Phased Array

1a Limited testing of these technologies will be accomplished with

existing funding as a basis to assess future use. These

approaches do not add water to the annulus. The current UT

approach adds 3-5000 gallons of water per inspection.

4.1.2 E valuate Additional

NDE (Flash

Thermography)

2 Some vendor investigations will be conducted but development

and testing will be deferred.

4.2.1 Automated Annulus

Camera System

2 The annulus camera system concept will be developed but

deployment will be deferred pending system performance.

4.3.1 Visual– Robotic

Crawler in Air Slots

1b The crawler will be fabricated and deployed in Tank AY-101 to

inspect the air slots.

4.3.2 Visual–Robotic

Annulus Air Supply Pipe

Inspections

3 The annulus air supply pipe inspection will be deferred until

after retrieval to avoid schedule impacts.

4.3.3 NDE–SAFT and T-

SAFT

1c Limited demonstration work will be conducted with SAFT and

T-SAFT. Deployment will be deferred.

4.3.4 NDE–Robotic

Crawler (Guided Wave in

Air Slots)

1c The Crawler developed for visual inspection (Task 4.3.1) will be

designed such that the platform can be used for NDE after a

successful visual deployment.

4.3.5 NDE–Guided Wave

System (Across Tank

Diameter)

3 Limited development will be conducted to assess feasibility.

Deployment will be deferred pending an assessment of the

viability.

4.4.1 Perform UT with

Existing Procedure

1a The annulus bottom will be inspected as part of the normal UT

scanning procedure. Consideration will be given to assessing

tanks with moisture in the tertiary collection system beneath the

annulus liner.

4.5.1 Use of

Thermocouples to Detect

Leaks

2 An engineering evaluation will be conducted to assess historic

thermocouple data with a heat transfer model of the air slots to

see if a correlation between temperatures and leak location can

be made. Follow-on actions will be determined based on the

results.

4.6.1 Improved Annulus

Air Monitoring Design

(CAM)

3 No viable concepts have been identified to improve the CAM

design approach as a means of detecting tank leaks into the

annulus.

5.1.1 2014 Corrosion

Work on Tank AY-102

Steel

1a The corrosion work is ongoing with FY 2014 funding. Results

will be reviewed by the EPOC.

5.2.1 Dehumidifiers on

Annulus Air Inlet

3 Dehumidifiers will not be installed on the annulus inlet air. The

annulus ventilation system will be operated with ambient air

with outages limited by the current operating specifications.

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6-3



5.3.1 Core Sample AY-

102 at Bottom Plate

1a This activity was deleted to avoid delays in Tank AY-102

retrieval.

5.3.2 Analyze AY-102

Sample (Corrosion

Testing)

1a This activity was deleted to avoid delays in Tank AY-102

retrieval.

5.3.3 Sample Annulus

with Robotic Crawler

2 The annulus sampling in Tank AY-102 is a priority in the

absence of taking the bottom sample in Tank AY-102.

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7-1

7.0 REFERENCES

ASTM G129-00, 2013, Slow Strain Rate Testing to Evaluate the Susceptibility of Metallic

Materials to Environmentally Assisted Cracking, ASTM International, West

Conshohocken, PA.

ASTM G61-86e1, 2003, Standard Test Method for Conducting Cyclic Potentiodynamic

Polarization Measurements for Localized Corrosion Susceptibility of Iron-, Nickel-, or

Cobalt-Based Alloys, ASTM International, West Conshohocken, PA.

OSD-T-151-00007, 2013, Operating Specifications for the Double-Shell Storage Tanks, Rev. 12,

Washington River Protection Solutions, LLC, Richland, Washington.

RPP-13639, 2014, Caustic Limits Report – For Period Ending January 1, 2014, Rev. 10,


RPP-29600, [DRAFT], Evaluation of Tank 241-AW-104 Supernatant and Interstitial Liquid

Hydroxide Concentration, Rev. 2, Washington River Protection Solutions, LLC,

Richland, Washington.

RPP-52349, 2013, Tank 241-AN-106 Thermal Analyses Uncertainty Evaluation, Rev. 0,


RPP-53070, 2013, Tank 241-AN-101 Thermal Analysis, Rev. 0, Washington River Protection

Solutions, LLC, Richland, Washington.

RPP-53793, 2012, Tank 241-AY-102 Leak Assessment Report, Rev. 0, Washington River

Protection Solutions, LLC, Richland, Washington.

RPP-56864, 2014, Tank 241-AY-102 Thermal Evaluation of Supernatant Reduction, Rev. 0,


RPP-7574, 2010, Double-Shell Tank Integrity Program Plan, Rev. 3, Washington River


RPP-7795, 2013, Technical Basis for the Chemistry Control Program, Rev. 11, Washington

River Protection Solutions, LLC, Richland, Washington.

RPP-8974, 2011, Chemistry Control Program Calculation Methodology for Prediction of

Hydroxide Depletion in Double-Shell Tanks, Rev. 4, Washington River Protection


RPP-ASMT-54634, 2013, Propensity for Corrosion in 241-AY-102 Annulus, Rev. 0, Washington


RPP-ASMT-55798, 2013, Alternatives Evaluation for Tank 241-AY-102 Robotic Inspection,

Rev. 0, Washington River Protection Solutions, LLC, Richland, Washington.

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7-2

RPP-ASMT-55871, 2013, Propensity for Corrosion in 241-AY-102 Annulus, Rev. 0, Washington


RPP-ASMT-57582, Second Workshop of the High Level Waste Integrity Assessment Panel:

Extent of Condition and Balance of Program, Rev. 0, Washington River Protection


RPP-RPT-56464, 2014, 241-AY-102 Leak Detection Pit Drain Line Inspection Report, Rev. 0,


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A-i

Appendix A

QUALITATIVE RISK RANKING PERFORMANCE MEASURES

A-

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A-ii

CONTENTS

A1.0 QUALITATIVE RISK RANKING OF DOUBLE-SHELL TANK FAILURE .............. A-1

A1.1 Performance Measures .......................................................................................... A-2

A1.2 Risk Ranking Results ............................................................................................ A-2

A1.3 Consequences ........................................................................................................ A-2

A2.0 CONSTRUCTION QUALITY ........................................................................................ A-3

A2.1 Primary Tank Bottom Weld Rejection Rates ........................................................ A-3

A2.2 Primary Tank Bottom Bulging .............................................................................. A-4

A2.3 Secondary Liner Bottom Budging ......................................................................... A-4

A2.4 Refractory and Foam ............................................................................................. A-5

A2.5 Post Weld Heat Treatment .................................................................................... A-5

A2.6 Raw Water Idle Time ............................................................................................ A-6

A3.0 PLATE MATERIAL AND THICKNESS ....................................................................... A-7

A3.1 Plate Material ........................................................................................................ A-8

A3.2 Primary Tank Bottom Thickness ........................................................................... A-8

A3.3 Secondary Liner Bottom Thickness ...................................................................... A-8

A3.4 Ultrasonic Testing on Primary Tank Wall ............................................................ A-8

A4.0 WATER INTRUSION ................................................................................................... A-10

A4.1 Annulus Water Intrusion ..................................................................................... A-11

A4.2 Leak Detection Pit Intrusion ............................................................................... A-11

A5.0 TEMPERATURE HISTORY AND EXCURSIONS .................................................... A-12

A5.1 Tank Temperatures .............................................................................................. A-12

A5.2 Heat Load ............................................................................................................ A-13

A5.3 Fill Cycles ........................................................................................................... A-13

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A-iii

A6.0 CONTINUITY OF ANNULUS VENTILATION OPERATION ................................. A-14

A6.1 Annulus Ventilation Outage ................................................................................ A-15

A7.0 CORROSION CHEMISTRY HISTORY ...................................................................... A-16

A7.1 Age of Tanks ....................................................................................................... A-16

A7.2 Year Out-of-Specification ................................................................................... A-17

A7.3 Predictive Corrosion History ............................................................................... A-17

A8.0 HOMOGENEITY OF WASTE ..................................................................................... A-18

A8.1 ASolids Volume .................................................................................................. A-19

A9.0 COMPLEXITY OF CONTENTS .................................................................................. A-20

A9.1 Interstitial Liquid Nitrite/Nitrate Ratio ............................................................... A-21

A9.2 Hydroxide Ion Concentration .............................................................................. A-21

A9.3 Total Organic Carbon .......................................................................................... A-21

A10.0 REFERENCES ............................................................................................................... A-22

TABLES

Table A-1. Qualitative Risk Ranking of Double-Shell Tank Weighting System ................. A-1

Table A-2. Risk Ranking Data for Construction Quality ...................................................... A-3

Table A-3. Risk Ranking Data for Plate Material and Thickness ......................................... A-7

Table A-4. Risk Ranking Data for Water Intrusion ............................................................ A-10

Table A-5. Risk Ranking Data for Temperature History and Excursions .......................... A-12

Table A-6. Risk Ranking Data for Continuity of Annulus Ventilation Operation ............. A-14

Table A-7. Risk Ranking Data for Corrosion Chemistry History ....................................... A-16

Table A-8. Risk Ranking Data for Homogeneity of Waste ................................................ A-18

Table A-9. Risk Ranking Data for Complexity of Contents ............................................... A-20

FIGURES

Figure A-1. Risk Ranking Comparison Graph ....................................................................... A-2

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A-iv

TERMS

Acronyms

BBI Best Basis Inventory

CFC chloroflouocarbon

DMCS Document Management and Control System

DST double-shell tank

ISL interstitial liquid

NCR nonconformance report

NO2- nitrite ion

NO3- nitrate ion

OH- hydroxide ion

PCSACS Personal Computer Surveillance Analysis Computer System

POC point of contact

QA quality assurance

SDDS Surveillance Data Display System

TOC total organic carbon

UT ultrasonic testing

HIAP High-Level Waste Integrity Assessment Panel

WRPS Washington River Protection Solutions, LLC

HTWOS Hanford Tank Waste Operations Simulator

SST single-shell tank

WTP Waste Treatment and Immobilization Plant

DF LAW direct feed low-activity waste

Units

°C Celcius

°F Fahrenheit

BTU British thermal unit

hr hour

in. inch

M molar

mil one thousandth of an inch

% percent

ft foot

Kgal thousand gallons

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A-1

A1.0 QUALITATIVE RISK RANKING OF DOUBLE-SHELL TANK FAILURE

The High-Level Waste Integrity Assessment Panel (HIAP) recommended a qualitative risk-

ranking of the double-shell tanks (DSTs) as a basis to prioritize more rigorous inspection

activities. The risk ranking cannot be used to “predict” failures. It is merely a ranking based on

potential factors that may influence operating life. This ranking will be updated when the

forensic activities for Tank 241-AY-102 (AY-102) yield information on the cause of the bottom

plate failure. The weights have been provided by Washington River Protection Solutions, LLC

(WRPS) personal in Tank and Pipeline Integrity (Table A-1).

Table A-1. Qualitative Risk Ranking of Double-Shell Tank Weighting System

Criteria Measures Weights

A1.0 Construction Quality 25

A1.1 Primary Tank Bottom Weld Rejection Rates 3

A1.2 Primary Tank Bottom Bulging 6

A1.3 Secondary Liner Bottom Budging 3

A1.4 Refractory and Foam 3

A1.5 Post Weld Heat Treatment 7

A1.6 Raw Water Idle Time 3

A2.0 Plate Material and Thickness 15

A2.1 Plate Material 6

A2.2 Primary Tank Bottom Thickness 3

A2.3 Secondary Liner Bottom Thickness 1

A2.4 Ultrasonic Testing on Primary Tank Wall 5

A3.0 Water Intrusion 5

A3.1 Annulus Water Intrusion 3

A3.2 Leak Detection Pit Intrusion 2

A4.0 Temperature History and Excursions 5

A4.1 Tank Temperatures 2

A4.2 Heat Load 2

A4.3 Fill Cycles 1

A5.0 Continuity of Annulus Ventilation Operation 10

A5.1 Annulus Ventilation Outage 10

A6.0 Corrosion Chemistry History 20

A6.1 Age of Tanks 10

A6.2 Year Out-of-Specification 6

A6.3 Predictive Corrosion History 4

A7.0 Homogeneity 10

A7.1 Solids Volume 10

A8.0 Complexity of Contents 10

A8.1 Interstitial Liquid Nitrite/Nitrate Ratio 5

A8.2 Hydroxide Ion Concentration 3

A8.3 Total Organic Carbon 2

Total 100 100

Risk ranking criteria are the logical categories of influence provided by the HIAP. The measures

were developed from available data on the 28 DSTs. These data points were quantified and

referenced back to source documents to the extent possible.

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A-2

A1.1 PERFORMANCE MEASURES

For each of the evaluation criteria, multiple measures have been developed to help evaluate their

respective criterion and to act as discriminators for making comparisons between alternatives.

Data for each tank is provided and referenced in the following sections. The scoring is

structured so that the tanks can be discriminated according to performance differences in risk;

higher scores represent higher risk.

A1.2 RISK RANKING RESULTS

As shown in Figure A-1, the AY, AZ and SY Farm tanks score highest in the risk ranking. The

individaul contributions of the criteria categories show that the construction quality issues and

corrosion history are primary drivers.

Figure A-1. Risk Ranking Comparison Graph

A1.3 CONSEQUENCES

The future loss of additional DSTs is being evaluated with system planning to document findings

from Hanford Tank Waste Operations Simulator (HTWOS) model runs which assume a tank

failure every four years (RPP-56408, Selected Scenarios for the River Protection Project System

Plan, Revision 7). Losing one or more DSTs due to leaks has significant consequences, which

must be managed. If the leaking DST is immediately retrieved the general impacts which must

be managed are delays in single-shell tank (SST) retrieval and potential delays in in processing

[e.g. feed delivery to the Waste Treatment and Immobilization Plan (WTP) or waste returns from

direct feed low-activity waste (DF LAW)]. There are planning cases to provide varying numbers

of new DSTs to mitigate these impacts.

0

10

20

30

40

50

60

70

80

90

AY-

10

2

AY-

10

1

AZ-

10

2

AZ-

10

1

SY-1

01

SY-1

02

SY-1

03

AN

-10

7

AN

-10

6

AN

-10

2

AW

-10

6

AW

-10

4

AN

-10

1

AW

-10

1

AN

-10

5

AW

-10

5

AN

-10

4

AN

-10

3

AW

-10

3

AW

-10

2

AP

-10

8

AP

-10

3

AP

-10

4

AP

-10

5

AP

-10

2

AP

-10

7

AP

-10

1

AP

-10

6

Risk Ranking SummaryComplexity ofContentsHomogeneity of Waste

Corrosion ChemistryHistoryContinuity of AnnulusVentilation OperationTemperature Historyand ExcursionsWater Intrusion

Plate Material andThicknessConstruction Quality

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A-3

A2.0 CONSTRUCTION QUALITY

Table A-2 contains values for weld rejection rate, primary tank bottom bulging, secondary liner

bottom bulging, refractory and foam, post weld heat treatment, and raw water idle time.

Table A-2. Risk Ranking Data for Construction Quality

Tank Weld Rejection

Rate

Primary Tank Bottom Bulging

Secondary Liner Bottom

Bulging

Refractory and Foam

Post Weld Heat

Treatment

Raw Water Idle Time

AY-101 10.2% None Identified Bulging Sig. Damage 1000°F for 3 h > 10 months

AY-102 33.8% None Identified Bulging Sig. Damage 915°F for 3 h > 10 months

AZ-101 14.5% None Identified Few Issues No Damage 1000°F for 3 h > 10 months

AZ-102 6.3% None Identified Few Issues No Damage 1000°F for 3 h > 10 months

SY-101 30.1% Bulging Bulging No Damage 1000°F for 3 h —

SY-102 21.9% None Identified Bulging Minor Damage 1100°F for 1 h —

SY-103 25.7% Bulging Bulging No Damage 1100°F for 1 h —

AW-101 30% None Identified None Identified Minor Damage 1100°F for 1 h 9 months

AW-102 31% None Identified Bulging No Damage 1000°F for 3 h 8 months

AW-103 27% None Identified None Identified No Damage 1000°F for 3 h 7 months



AW-106 24% None Identified Bulging No Damage 1000°F for 3 h 7 months

AN-101 13% None Identified None Identified No Damage 1000°F for 3 h 8 months



AN-104 9% None Identified None Identified Minor Damage 1000°F for 3 h 10 months




AP-101 6% None Identified None Identified No Damage 1000°F for 3 h —







AP-108 5% None Identified None Identified Minor Damage 950°F for 5 h —

A2.1 PRIMARY TANK BOTTOM WELD REJECTION RATES

Primary tank bottom weld rejection rates are documented in RPP-ASMT-53793, Tank

241-AY-102 Leak Assessment Report; RPP-RPT-54817, 241-AY-101 Tank Construction Extent of

Condition Review for Tank Integrity; RPP-RPT-54818, 241-AZ Tank Farm Construction Extent

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A-4

of Condition Review for Tank Integrity; RPP-RPT-54819, 241-SY Tank Farm Construction

Extent of Condition Review for Tank Integrity; RPP-RPT-55981, 241-AW Tank Farm

Construction Extent of Condition Review for Tank Integrity; RPP-RPT-55982, 241-AN Tank

Farm Construction Extent of Condition Review for Tank Integrity; RPP-RPT-55983, 241-AP

Tank Farm Construction Extent of Condition Review for Tank Integrity; TOC-PRES-14-1370,

Double-Shell Tank Construction: Extent of Condition. These weld rejection values were

calculated based on radiographic film which evaluated 1 ft sections of weld. The radiographic

reports were used to determine the weld rejection percentage (Table A-2).

(1) Less than 10% weld rejection

(3) 10 to 20% weld rejection

(5) More than 20% weld rejection

A2.2 PRIMARY TANK BOTTOM BULGING

Primary tank bottom bulging refers to the 3/8 in./ft or a peak-to-valley difference greater than the

2 in. specifications for the primary tank bottom. The primary tanks were stress relieved to

reduce stresses in the metal and reduce the possibility of stress corrosion cracking. However,

many of the primary tank bottoms were found to be out specification concerning flatness. Some

repairs were attempted but generally failed. The bulges were then accepted as is and left in

place. The bulges create extra stress in the steel when loads are applied (Table A-2).

This information is documented in the following reports: RPP-ASMT-53793, RPP-RPT-54817,

RPP-RPT-54818, RPP-RPT-54819, RPP-RPT-55981, RPP-RPT-55982, RPP-RPT-55983, and

TOC-PRES-14-1370.

(1) No flatness issues. No questionable repairs and/or acceptance. – There were no

bulges specifically identified or the flatness was described as “generally good” in the

Quality Assurance (QA) Log Books. Out-of-tolerance locations were identified.

However, they were found to be within tolerance after lowering the tank bottom.

(5) Many flatness issues. Questionable repairs and/or acceptance. – Several

out-of-tolerance areas existed after the bottom was lowered and nonconformance

reports (NCR) were generated (typically six or more out-of-tolerance locations or

severe bulging near the knuckle region).

A2.3 SECONDARY LINER BOTTOM BUDGING

Secondary liner bottom budging refers to the 3/8 in./ft and/or a peak-to-valley difference greater

than 2 in. specifications for the secondary liner bottom. The secondary liner was not stress

relieved and residual stresses exist near the welds. Bulging in the secondary liner can add

significant stresses to the steel when loads are applied. These bulges can also lead to the

cracking and breaking of the refractory (Table A-2).

(1) No flatness issues. No questionable repairs and/or acceptance. – There were no

bulges specifically identified or the flatness was described as “generally good” in the

QA Log Books.

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A-5

(3) Few flatness issues. Questionable repairs and/or acceptance. – Out-of-tolerance

locations were identified. However, they were found to be within tolerance after

lowering the tank bottom.

(5) Many flatness issues. Questionable repairs and/or acceptance. – Several out-of-

tolerance areas existed after the bottom was lowered and nonconformance reports

were generated (typically six or more out-of-tolerance locations or severe bulging

near the knuckle region).

A2.4 REFRACTORY AND FOAM

The primary purpose of the refractory was to keep the concrete foundation temperature below

500°F during stress relieving of the primary tank. However, the refractory supports the primary

tank. If the compressive strength of the refractory is not such that it can withstand the loads

applied to the tank, the refractory will be crushed, and the primary tank bottom can settle. This

condition would create an uneven surface along the tank bottom and introduce stresses to the

steel (Table A-2).

Tanks AY-101 and AY-102 had bulging issues which resulted in replacing the outer few feet of

the Kaolite refractory material and replacing it with concrete. This action could have resulted in

different compression properties resulting in unexpected stresses on the bottom plate at the

interface between the concrete and Kaolite. Additionally, insulating foam (styrene foam) was

used to fill voids between the bottom plate and the refractory. It is likely that

chlorofluorocarbons (CFC) were in the styrene foam used at the time of AY Farm construction.

The CFCs were blowing agents and would be trapped in the expanded foam. Decomposition

products of the CFC could be corrosive to the tank steels. These include chlorine free radicals

and chlorodifluoracetic acid. For a full discussion of the use of foam, refer to Section 3.2.5 in

RPP-ASMT-53793.

(1) No damage/Minor damage – No damage to the refractory were noted in any of the

reviewed documentation. This includes simple repairs to minor cracking that was

usually the result of shrinkage cracking which occurred because of high temperatures

and curing too fast. Also, possible cracking caused from cribbing. Minor damage

consists of small areas of refractory damaged by cribbing which required chipping

removing material prior to placing new material.

(5) Significant damage – Damage which required large areas of refractory to be removed

due to post weld heat treatment; repairs including the use of structural concrete to

support the tank bottom.

A2.5 POST WELD HEAT TREATMENT

Post weld heat treatment information is documented in TOC-PRES-14-1370. These values are

obtained from Stress Relief and QA Log Books (Table A-2).

Tanks AY-101 and AY-102 are scored differently due to differing PWHT conditions. Tank

AY-102 temperature could not surpass 200°F for several days due to escaping steam on account

of free water boiling off the insulating concrete. Four days after stress relieving began; Tank

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A-6

AY-102 reached 915°F and was accepted as meeting the 1,000°F criteria according to

RPP-ASMT-53793.

(1) Reached 1100°F for one hour

(3) Reached 1000°F for three hours

(5) Did not reach 1000°F for three hours (or other issues)

A2.6 RAW WATER IDLE TIME

The primary tank was exposed to raw water which caused some pitting for hydrostatic testing,

dome construction, and preparation for hot feed receipt. Tank AN-107 and AW-104 were

checked for corrosion prior to radioactive service. Corrosion 20-30 mils deep was observed and

it was assumed the rest of the AN Farm tanks had similar amounts of corrosion. Water used in

AP Farm construction was inhibited and cathodic protection was used to protect the tanks (Table

A-2).

(1) Treated water and cathodic protection

(3) Less than ten months with raw water

(5) Greater than ten months with heated raw water

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A-7

A3.0 PLATE MATERIAL AND THICKNESS

Table A-3 contains values for plate material, primary tank bottom thickness, secondary liner

bottom thickness, and ultrasonic testing on primary tank walls.

Table A-3. Risk Ranking Data for Plate Material and Thickness

Tank Plate Material Primary Tank Bottom Thickness

Secondary Liner Bottom Thickness

Ultrasonic Testing on Primary Tank

Walls

AY-101 A515 3/8 in. 1/4 in. Reportable

AY-102 A515 3/8 in. 1/4 in. Reportable

AZ-101 A515 1/2 in. 3/8 in. Not Reportable

AZ-102 A515 1/2 in. 3/8 in. Reportable

SY-101 A516 1/2 in. 3/8 in. Reportable



AW-101 A537 1/2 in. 3/8 in. Reportable

AW-102 A537 1/2 in. 3/8 in. Not Reportable





AN-101 A537 1/2 in. 3/8 in. Reportable

AN-102 A537 1/2 in. 3/8 in. Reportable

AN-103 A537 1/2 in. 3/8 in. Not Reportable





AP-101 A537 1/2 in. 3/8 in. Not Reportable

AP-102 A537 1/2 in. 3/8 in. Reportable






AP-108 A537 1/2 in. 3/8 in. Reportable

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A-8

A3.1 PLATE MATERIAL

Plate material is documented in TOC-PRES-14-1370. This information was gathered from Mill

Test Reports (Table A-3).

(1) ASTM A537

(3) ASTM A516

(5) ASTM A515

A3.2 PRIMARY TANK BOTTOM THICKNESS

Primary tank bottom thickness is documented in TOC-PRES-14-1370. Following the AY Farm

construction, primary tank bottom plate thickness was increased in an attempt to reduce the

bottom bulging (Table A-3).

(1) 1/2 in.

(5) 3/8 in.

A3.3 SECONDARY LINER BOTTOM THICKNESS

Secondary liner bottom thickness is documented in TOC-PRES-14-1370. Following the AY

Tank Farm construction, secondary liner plate thickness was increased in an attempt to reduce

the bottom bulging (Table A-3).

(1) 3/8 in.

(5) 1/4 in.

A3.4 ULTRASONIC TESTING ON PRIMARY TANK WALL

Ultrasonic testing (UT) on the primary tank wall is to inspect for general wall thinning, pitting

and linear indications (cracking) of the tank wall per RPP-7574, Double-Shell Tank Integrity

Program Plan. WRPS has generated numerous UT Inspection Results documents. At 100%

completion, all 28 DSTs have at least one UT Inspection Report and each report is in Document

Management and Control System (DMCS). Presently, 23 of 28 DSTs have two or more

completed UT Reports. Three DSTs (AP-102, AP-104 and AP-106) are slated to have the

second UT inspections completed in 2014 with the final two DSTs (AN-103 and AN-104) UT

inspections planned in 2015.

To determine general wall thinning, pitting, and/or linear indications (cracking) for all 28 DSTs;

the UT data results from each tank (including the bottom knuckle and Course one, two, three,

and four) were compared to the minimum UT measured data point minus the nominal wall

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A-9

thickness (Table A-3). After comparing the minimum wall thickness results from each section of

the 28 tanks, the overall rating of each tank is delineated as follow:

(1) Not Reportable

(3) Reportable Level (10% plate wall thickness; pitting 25% of plate thickness and

cracking <6 in. of 10% plate thickness)

(5) Action Level (20% plate wall thickness; pitting 50% plate thickness and cracking

>12 in. of 20% plate thickness or <12 in. of 50% plate thickness)

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A-10

A4.0 WATER INTRUSION

Table A-4 shows whether there is annulus water intrusion and leak detection pit intrusion.

Table A-4. Risk Ranking Data for Water Intrusion

Tank Annulus Water Intrusion Leak Detection Pit Intrusion

AY-101 Yes Exceeds maximum authorized limit

AY-102 Yes Exceeds maximum authorized limit

AZ-101 No Exceeds maximum authorized limit

AZ-102 No Exceeds maximum authorized limit

SY-101 No Exceeds maximum authorized limit

SY-102 No Exceeds maximum authorized limit

SY-103 No Exceeds structural limit

AW-101 No No

AW-102 No No

AW-103 No Exceeds maximum authorized limit

AW-104 No No

AW-105 No Exceeds structural limit

AW-106 No No

AN-101 No No

AN-102 No No

AN-103 No No

AN-104 No No

AN-105 No No

AN-106 No No

AN-107 No Exceeds structural limit

AP-101 No No

AP-102 No No

AP-103 No No

AP-104 No No

AP-105 No Exceeds maximum authorized limit

AP-106 Yes Exceeds maximum authorized limit



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A-11

A4.1 ANNULUS WATER INTRUSION

Annulus water intrusion is documented in RPP-7695, Double-Shell Tank Annulus Ventilation

Engineering Study, for AY and AZ Farms (Table A-4). Tank AP-106 has an annulus water

intrusion documented in RPP-RPT-38738, Double-Shell Tank Integrity Inspection Report for

241-AP Tank Farm. Moisture in the annulus may lead to corrosion of the primary tank. Active

intrusion of water to the annulus via cracks in the concrete dome is a corrosion issue for the

primary tank. Only the AY Tanks have had significant water intrusion (RPP-RPT-33273, 241-

AY-101/102 Annulus Moisture Intrusion Analysis).

(1) None or very minor

(5) Yes

A4.2 LEAK DETECTION PIT INTRUSION

Leak detection pit intrusion is documented in RPP-RPT-55666, Double-Shell Tank Tertiary Leak

Detection System Evaluation. Moisture in the soil around the tank and in the air used for annulus

ventilation may create corrosion conditions beneath the secondary liner (Table A-4).

(1) No

(3) Exceeds maximum authorized limit

(5) Exceeds structural limit

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A-12

A5.0 TEMPERATURE HISTORY AND EXCURSIONS

Table A-5 contains values for tank temperature, heat loads, and fill cycles.

Table A-5. Risk Ranking Data for Temperature History and Excursions

Tank Tank Temperature Heat Load Fill Cycles

AY-101 108°F 52,392 BTU/hr Normal Use

AY-102 156°F 106,989 BTU/hr Normal Use

AZ-101 163°F 193,568 BTU/hr Normal Use

AZ-102 148°F 107,796 BTU/hr Normal Use

SY-101 86°F 6,224 BTU/hr Normal Use

SY-102 72°F 9,702 BTU/hr Evaporator 242-S Feed

SY-103 90°F 17,596 BTU/hr Normal Use

AW-101 109°F 24,520 BTU/hr Normal Use

AW-102 86°F 19,537 BTU/hr Evaporator 242-A feed





AN-101 99°F 26,505 BTU/hr Normal Use







AP-101 117°F 18,470 BTU/hr Normal Use








A5.1 TANK TEMPERATURES

Tank temperatures are documented in RPP-5926, Steady-State Flammable Gas Release Rate

Calculation and Lower Flammability Level Evaluation for Hanford Tank Waste. These values

are obtained from actual values currently in the tank waste (Table A-5). The highest tank

temperatures in Personal Computer Surveillance Analysis Computer System (PCSACS) are

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A-13

documented for a four month period ending in 2014 in RPP-13639, Caustic Limits Report – For

Period Ending January 1, 2014.

(1) Less than 30°C

(3) 30 to 50°C

(5) Above 50°C

A5.2 HEAT LOAD

Heat load is derived from the radionuclide content documented in the Best Basis Inventory

(BBI). Total heat in both the sludge and supernatant is provided (Table A-5).

(1) Under 50,000 BTU/hr

(3) 50,000 to 100,000 BTU/hr

(5) Over 100,000 BTU/hr

A5.3 FILL CYCLES

The evaporator feed tanks were saw repeated transfers associated with feeding the

242-S Evaporator (SY-102) and the 242-A Evaporator (AW-102). The additional fatigue related

stress on these two tanks is reflected by the number of fill cycles (Table A-5).

(1) Normal use

(5) Evaporator feed tank

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A-14

A6.0 CONTINUITY OF ANNULUS VENTILATION OPERATION

Table A-6 contains how long an annulus ventilation outage occurred.

Table A-6. Risk Ranking Data for Continuity of Annulus Ventilation Operation

Tank Annulus Ventilation Outage

AY-101 10 years

AY-102 10 years

AZ-101 5 years

AZ-102 5 years

SY-101 1 month

SY-102 1 month

SY-103 1 month

AW-101 1 month

AW-102 1 month

AW-103 1 month

AW-104 1 month

AW-105 1 month

AW-106 1 month

AN-101 3 months

AN-102 3 months

AN-103 3 months

AN-104 3 months

AN-105 3 months

AN-106 3 months

AN-107 3 months

AP-101 1 month

AP-102 1 month

AP-103 1 month

AP-104 1 month

AP-105 1 month

AP-106 1 month

AP-107 1 month

AP-108 1 month

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A-15

A6.1 ANNULUS VENTILATION OUTAGE

Annulus ventilation outage timing is derived from temperature rise similar to RPP-56864,

Tank 241-AY-102 Thermal Evaluation of Supernatant Reduction, or exhauster status log sheets

found in IDMS under document number TO-040-035. For AY and AZ Farms, RPP-7695 was

used (the worst annulus outage is believed to be Tank AY-101 which, except for a brief period in

1997, was off from January 1992 to January 2001. This time period was about nine years).

Metrics are for the longest annulus downtime at one time (Table A-6).

(1) Less than two months

(3) Two months to two years

(5) Greater than two years

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A-16

A7.0 CORROSION CHEMISTRY HISTORY

Table A-7 contains values for the age of tanks, the years out-of-specification, and predictive

corrosion history.

Table A-7. Risk Ranking Data for Corrosion Chemistry History

Tank Age of Tanks Years Out-of-Specification Predictive Corrosion History

AY-101 44 years 6.83 years > 3 years

AY-102 44 years 6.58 years 0 years (est.)

AZ-101 40 years 1.67 years 0 years (est.)

AZ-102 40 years 0.42 years > 3 years

SY-101 38 years 0 years ~2 years

SY-102 38 years 0.5 years > 3 years

SY-103 38 years 0 years 0 years (est.)

AW-101 35 years 0 years 0 years (est.)

AW-102 35 years 0 years > 3 years





AN-101 34 years 0 years > 3 years

AN-102 34 years 12.83 years 0 years (est.)

AN-103 34 years 0 years 0 years (est.)



AN-106 34 years 0.25 years > 3 years

AN-107 34 years 18.42 years 0 years (est.)

AP-101 28 years 0 years 0 years (est.)


AP-103 28 years 1.5 years 0 years (est.)






A7.1 AGE OF TANKS

The DSTs range in age from 28 to 44 years old. The age of the tanks is a risk factor in

determining soundness (Table A-7).

(1) Less than 30 years old

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A-17

(3) 30 to 35 years old

(5) Greater than 35 years old

A7.2 YEAR OUT-OF-SPECIFICATION

Years out-of-specification sampling is documented in Tables B-1 and B-3 of RPP-7795,

Technical Basis for the Chemistry Control Program (Table A-7).

(1) Less than one year

(3) one year to ten years

(5) More than ten years

A7.3 PREDICTIVE CORROSION HISTORY

Predictive corrosion history is partly documented in RPP-7795 and RPP-13639 (Table A-7).

And best estimate from corrosion mitigation point of contact (POC) (Currently, [May 2014] it is

predicted that Tank AZ-102 has been out-of-specification since April 2013).

(1) Less than 0.5 years

(3) 0.5 years to three years

(5) Greater than three years

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A-18

A8.0 HOMOGENEITY OF WASTE

Table A-8 contains values for the amount of sludge, saltcake, and supernatant in each DST.

Table A-8. Risk Ranking Data for Homogeneity of Waste

Tank Sludge Saltcake Supernatant

AY-101 105 Kgal 0 Kgal 893 Kgal

AY-102 151 Kgal 0 Kgal 643 Kgal

AZ-101 52 Kgal 0 Kgal 773 Kgal

AZ-102 105 Kgal 0 Kgal 886 Kgal

SY-101 0 Kgal 255 Kgal 864 Kgal



AW-101 0 Kgal 396 Kgal 736 Kgal






AN-101 403 Kgal 31 Kgal 340 Kgal







AP-101 0 Kgal 33 Kgal 1200 Kgal








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A-19

A8.1 SOLIDS VOLUME

The chemistry is controlled in the supernatant but there is no monitor of the chemistry at the

bottom plate surface. The level of solids represents a layer that solution concentrations must

penetrate from the supernatant layer to the surface of the plate. The total volume of solids is an

indirect reflection of the concentration gradient between the supernatant and the corrosion layer

next to the bottom plate. These sludge and salt cake volumes are taken from HNF-EP-0182,

Waste Tank Summary Report for Month Ending February 28, 2014, and is summarized in Table

A-8.

In addition to the solids level, certain tanks received solids through a layer of supernatant that

was outside the chemistry control limits. The result is that the interstitial liquid (ISL) in the

solids is more likely to have corrosive properties. These tanks are SY-102, AN-106, AW-101,

AW-104 and AY-102.

(1) No solids

(3) Sludge containing solids

(5) Solid receipt through off-spec supernatant

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A-20

A9.0 COMPLEXITY OF CONTENTS

Table A-9 contains values for nitrite (NO2-)/nitrate (NO3

-) ratio, hydroxide (OH-) concentration,

and total organic carbon (TOC) concentration.

Table A-9. Risk Ranking Data for Complexity of Contents

Tank NO2/NO3 Ratio OH- TOC

AY-101 13.44 0.0013 M 0.09 M

AY-102 0.52 0.002 M 0.15 M

AZ-101 1.57 0.67 M 0.13 M

AZ-102 8.43 0.012 M 0.08 M

SY-101 0.86 2.04 M 0.53 M

SY-102 0.74 1.26 M 0.38 M

SY-103 1.3 2.22 M 0.7 M

AW-101 0.79 5.21 M 0.21 M

AW-102 No Data No Data No Data

AW-103 0.5 1.11 M 0.47 M

AW-104 0.84 1.19 M 1.83 M

AW-105 0.27 0.42 M 0.79 M

AW-106 0.8 1.32 M 0.43 M

AN-101 0.65 0.45 M 0.29 M

AN-102 0.56 0.136 M 2.02 M

AN-103 1.37 4.81 M 0.4 M

AN-104 0.95 3.41 M 0.32 M

AN-105 0.88 2.7 M 0.308 M

AN-106 0.87 0.005 M 0.12 M

AN-107 0.43 0.001 M 3.66 M

AP-101 No Data No Data No Data


AP-103 0.67 1.11 M 0.34 M


AP-105 0.38 3.21 M 0.23 M



AP-108 0.61 2.55 M 0.32 M

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A-21

A9.1 INTERSTITIAL LIQUID NITRITE/NITRATE RATIO

NO2- is a corrosion inhibitor and NO3

- is a corrosion promoter. The ratio of the concentration of

NO2- divided by the concentration of NO3

- in the ISL of the solids appears to be significant in

estimating the amount of corrosion in the ISL and supernatant. The ISL limit in OSD-T-151-

00007, Operating Specifications for the Double-Shell Storage Tanks, Table 1.5.1-2, is [NO2-

]/[NO3-] >0.32 M. Studies indicate that a ratio of about 0.15 may also be significant. See RPP-

7795, for an estimate of the TOC in both supernatant and ISL (Table A-9).

(1) 0.32 < [NO2-]/[NO3

-]

(3) 0.15 < [NO2-]/[NO3

-] < 0.32

(5) [NO2-]/[NO3

-] < 0.15

A9.2 HYDROXIDE ION CONCENTRATION

OH- concentration is a corrosion inhibitor in certain concentrations. When OH- concentration

can be measured directly it is a good indication if corrosion will occur at significant levels. RPP-

7795 has estimates of OH- concentrations for DST in different layers in the tank. For a worst

case, data from the lowest concentration in supernatant layers and layers in the ISL were used.

OH- concentration changes with time and reactions in the tank waste. OSD-T-151-00007, Tables

1.5.1-1 and 1.5.1-2, have OH- limits depending on the concentration of NO3-. Metrics are greatly

simplified (Table A-9).

(1) [OH-] > 0.3 M

(3) 0.01 M < [OH-] < 0.3 M

(5) [OH-] < 0.01 M

A9.3 TOTAL ORGANIC CARBON

Organics participate in chemical reactions which remove OH- from the supernatant and probably

the ISL of the solids. RPP-7795 documented TOC reactions and correlations that can estimate

the rate of supernatant loss of OH-. The reactions and correlations in the ISL are probably the

same as the supernatant, although this has not been proven. RPP-7795 or RPP-13639 was used

to determine TOC in the layers of supernatant and in ISL (Table A-9). This is about the only

tool available to metric the OH- in the ISL because there have not been any core samples since

February 14, 2008.

(1) TOC < 0.2 M

(3) 0.2 M < TOC < 0.7 M

(5) TOC > 0.7 M

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A-22

A10.0 REFERENCES

HNF-EP-0182, 2014, Waste Tank Summary Report for Month Ending February 28, 2014,


OSD-T-151-00007, 2013, Operating Specifications for the Double-Shell Storage Tanks, Rev 12,


RPP-13639, 2014, Caustic Limits Report – For Period Ending January 1, 2014, Rev. 10,

Washington River Solutions, LLC, Richland, Washington.

RPP-56408, 2013, Selected Scenarios for the River Protection Project System Plan, Revision 7,


RPP-56864, 2014, Tank 241-AY-102 Thermal Evaluation of Supernatant Reduction, Rev. 0,


RPP-5926, 2014, Steady-State Flammable Gas Release Rate Calculation and Lower

Flammability Level Evaluation for Hanford Tank Waste, Rev. 14, Washington River


RPP-7574, 2010, Double-Shell Tank Integrity Program Plan, Rev. 3, Washington River


RPP-7695, 2001, Double-Shell Tank Annulus Ventilation Engineering Study, Rev. 0A, CH2M

HILL Hanford Group Inc., Richland, Washington.

RPP-7795, 2013, Technical Basis for the Chemistry Control Program, Rev. 11, Washington


RPP-ASMT-53793, 2012, Tank 241-AY-102 Leak Assessment Report, Rev. 0, Washington River


RPP-RPT-33273, 2007, 241-AY-101/102 Moisture Intrusion Analysis, Rev. 0, CH2M HILL

Group Inc., Richland, Washington.

RPP-RPT-54817, 2013, 241-AY-101 Tank Construction Extent of Condition Review for Tank

Integrity, Rev. 0, Washington River Protection Solutions, LLC, Richland, Washington.

RPP-RPT-54818, 2013, 241-AZ Tank Farm Construction Extent of Condition Review for Tank


RPP-RPT-54819, 2013, 241-SY Tank Farm Construction Extent of Condition Review for Tank


RPP-RPT-55666, 2013, Double-Shell Tank Tertiary Leak Detection System Evaluation, Rev. 0,


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A-23

RPP-RPT-55981, 2013, 241-AW Tank Farm Construction Extent of Condition Review for Tank


RPP-RPT-55982, 2014, 241-AN Tank Farm Construction Extent of Condition Review for Tank


RPP-RPT-55983, 2014, 241-AP Tank Farm Construction Extent of Condition Review for Tank


TOC-PRES-14-1370, 2014, Double-Shell Tank Construction: Extent of Condition, Rev. 0,


RPP-RPT-38738, [DRAFT], Double-Shell Tank Integrity Inspection Report for 241-AP Tank

Farm, Rev. 4, Washington River Protection Solutions, LLC, Richland, Washington.

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