Release Stamp DOCUMENT RELEASE AND CHANGE FORM · LAWPS will be executed in a phased approach to support the Hanford Waste Treatment and Immobilization Plant(WTP). Initially, a modular

1 SPF-001 (Rev.D1)

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

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

1. Doc No: RPP-RPT-60822 Rev. 00

2. Title:Tank-Side Removal Safety Design Strategy

3. Project Number:TD101

☐ N/A 4. Design Verification Required:

☐ Yes ☒ No5. USQ Number: ☒ N/A

RPP-27195

6. PrHA Number Rev. ☒ N/A

Clearance Review Restriction Type:public

7. Approvals

Title Name Signature DateClearance Review Raymer, Julia R Raymer, Julia R 10/02/2018Design Authority Chamberlain, Blake E Chamberlain, Blake E 09/26/2018Checker Valentine, Michael G Valentine, Michael G 09/20/2018Document Control Approval Hood, Evan Hood, Evan 10/02/2018Originator Ferrara, Daro Ferrara, Daro 09/20/2018Other Approver Lanning, Roger D Lanning, Roger D 09/20/2018Other Approver McFerran, Brandon E McFerran, Brandon E 09/20/2018Other Approver Smith, Kimball E Smith, Kimball E 09/24/2018Responsible Engineering Manager Leonard, Michael W Leonard, Michael W 09/26/2018

8. Description of Change and Justification

Initial Release

9. TBDs or Holds ☒ N/A

10. Related Structures, Systems, and Components

a. Related Building/Facilities ☒ N/A b. Related Systems ☒ N/A c. Related Equipment ID Nos. (EIN) ☒ N/A

11. Impacted Documents – Engineering ☒ N/A

Document Number Rev. Title

12. Impacted Documents (Outside SPF):

N/A

13. Related Documents ☒ N/A

Document Number Rev. Title

14. Distribution

Name OrganizationBuczek, Jeffrey A PROGRAM INTEGRATIONChamberlain, Blake E TREATMENT FACILITY PROJ ENGRDavis, Neil R ENGINEERINGFerrara, Daro NUCLEAR SAFETYHoughton, David J TF PROJECTS & INTEGRITY ENGRNGLanning, Roger D NUCLEAR SAFETYLeonard, Michael W TREATMENT FACILITY PROJ ENGRSmith, Kimball E MISSION INTEGRATIONValentine, Michael G NUCLEAR SAFETY

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Oct 02, 2018DATE:

RPP-RPT-60822Revision 0

Low-Activity Waste Pretreatment System Sub-Project One Safety Design Strategy

Daro FerraraWashington River Protection Solutions, LLC

Roger LanningWashington River Protection Solutions, LLC

Checked by:

Michael ValentineWashington River Protection Solutions, LLC

Date PublishedSeptember 26, 2018

Prepared for the U.S. Department of EnergyOffice of River Protection

Contract No. DE-AC27-08RV14800

RPP-RPT-60822 Rev.00 10/2/2018 - 10:22 AM 2 of 60

Approved for Public Release;

Further Dissemination Unlimited

RPP-RPT-60822, Revision 0

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CONTENTS

1.0 PURPOSE AND SCOPE......................................................................................................1

2.0 DESCRIPTION OF LAWPS SUB-PROJECT ONE............................................................12.1 TSCR System and DFLAW Feed Delivery Upgrades Overview ..............................32.2 Major Hazards ............................................................................................................7

2.2.1 Hazards to the Public ..................................................................................242.2.2 Hazards to Onsite Workers .........................................................................242.2.3 Hazards to Facility Workers .......................................................................24

3.0 SAFETY STRATEGY........................................................................................................253.1 Safety Guidance and Requirements .........................................................................25

3.1.1 Safety-in-Design Approach.........................................................................253.1.2 Safety Functional Classification .................................................................263.1.3 Safety Design Criteria .................................................................................27

3.2 Hazard Identification................................................................................................293.3 Key Safety Decisions ...............................................................................................29

3.3.1 Anticipated Safety Functions ......................................................................303.3.2 Seismic and Other Natural Phenomena Design Categorization..................303.3.3 Confinement Strategy..................................................................................323.3.4 Fire Mitigation Strategy ..............................................................................343.3.5 Flammable Gas Control Strategy................................................................353.3.6 Direct Radiation Control Strategy...............................................................373.3.7 Criticality Control Strategy.........................................................................37

4.0 RISKS TO PROJECT SAFETY DECISIONS ...................................................................38

5.0 SAFETY ANALYSIS APPROACH AND PLAN .............................................................405.1 Tailored Approach for Developing the LAWPS Sub-Project One Safety

Basis .........................................................................................................................405.2 Change Control ........................................................................................................455.3 Safety Analysis Software .........................................................................................45

6.0 SAFETY DESIGN INTEGRATION TEAM – INTERFACES AND INTEGRATION..................................................................................................................45

7.0 REFERENCES....................................................................................................................46

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APPENDIX

A Confinement Evaluation .................................................................................................. A-i

LIST OF TABLES

Table 1. Major Hazards Associated with TSCR Demonstration and Spent IXC Storage Activities. .......................................................................................................................9

Table 2. TSCR and Spent IXC Storage Pad Representative Accidents and Safety Significant Controls. (13 sheets).................................................................................10

Table 3. Key Tank-Side Cesium Removal Safety-Significant Support and Interfacing Systems. .......................................................................................................................23

Table 4. Tank-Side Cesium Removal Initial Conditions and Other Assumptions Considered for Protection. ...........................................................................................23

Table 5. Safety Classification Guidelines. .................................................................................27

Table 6. LAWPS Sub-Project One Safety-in-Design Risks and Opportunities. .......................39

Table 7. Planned Safety Analysis and Deliverables for LAWPS Sub-Project One...................44

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LIST OF TERMS

ASME®1 American Society of Mechanical Engineers

CD Critical Decision

CIPT Contractor Integrated Project Team

CSER criticality safety evaluation report

CST crystalline silicotitanate

DFLAW direct feed low-activity waste

DOE U.S. Department of Energy

DSA documented safety analysis

DST double-shell tank

EG Evaluation Guideline

FRED Functions and Requirements Evaluation Document

FW facility worker

GENII Generation II Model for Environmental Dose Calculations

HC hazard category

HIHTL hose-in-hose transfer line

HVAC heating, ventilation, and air conditioning

ILST interim LAW storage tank

IPT Integrated Project Team

IXC ion exchange column

LAW low-activity waste

LAWPS Low-Activity Waste Pretreatment System

LFL lower flammability limit

MCNP5 Monte Carlo N-Particle Version 5

MCNP6 Monte Carlo N-Particle Version 6

NaOH sodium hydroxide

NDC Natural Phenomena Hazard Design Category

NPH natural phenomena hazard

ORP (DOE) Office of River Protection

PAC Protective Action Criteria

PDSA Preliminary Documented Safety Analysis

PSDR Preliminary Safety Design Report

PrHA Process Hazards Analysis

SAC specific administrative control

1 ASME is a registered trademark of the American Society of Mechanical Engineers, New York, New York.

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SC safety class

SDC Seismic Design Category

SDIT Safety Design Integration Team

SDS Safety Design Strategy

SIS Safety Instrumented Systems

SRED Safety Requirements Evaluation Document

SS safety significant

SSC structures, systems, and components

TOC Tank Operations Contractor

TSCR Tank-Side Cesium Removal

TSR Technical Safety Requirement

WAC waste acceptance criteria

WTP Hanford Waste Treatment and Immobilization Plant

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1.0 PURPOSE AND SCOPE

The purpose for this Safety Design Strategy (SDS) is to support implementation of U.S. Department of Energy (DOE) standard DOE-STD-1189-2008, DOE Standard ‒ Integration of Safety into the Design Process, for Sub-Project One of the Low-Activity Waste Pretreatment System (LAWPS) demonstration project, which is part of the Direct Feed Low-Activity Waste (DFLAW) Program. As indicated in DOE-STD-1189-2008, an SDS is to include the following:

1. Description of the overall safety strategy (Section 3.0);

2. Description of the strategy for certain high-cost, safety-related design decisions(Subsection 3.3);

3. Identification of key assumptions or inputs that might represent potential risks to those design decisions (Tables 2 and 5); and

4. Identification of the safety deliverables expected through the duration of the project(Section 5).

One purpose of the SDS is to describe the tailoring approach for the safety basis documents. While the tailoring approach for the safety basis documents has been summarized in the Tank-Side Cesium Removal (TSCR) project execution plan (PEP) (RPP-PLAN-62160, TD101, Tank Side Cesium Removal (TSCR) Demonstration Project Execution Plan), this SDS provides a more detailed description. As indicated in Subsection 2.4.4 of DOE-STD-1189-2008, DOE O 413.3 “allows tailoring of the critical decision (CD) process for projects based on ‘risk, size, and complexity’…The tailoring approach for safety basis documents must be:

described in the SDS; and

summarized in the PEP.”

Section 5.1 of this SDS includes a description of the tailoring approach for safety basis documents. In addition, Section 4.2.2.5 and Appendix B of RPP-PLAN-62160 include a summary of the tailoring approach. Documentation identified in this approach includes this SDS, a Preliminary Documented Safety Analysis (PDSA), an amendment to the tank farms Documented Safety Analysis (DSA) (RPP-13033, Rev. 7-G, Tank Farms Documented Safety Analysis), and revision to the tank farms Technical Safety Requirements (TSRs) (HNF-SD-WM-TSR-006, Rev. 8-C, Tank Farms Technical Safety Requirements).

2.0 DESCRIPTION OF LAWPS SUB-PROJECT ONE

LAWPS will be executed in a phased approach to support the Hanford Waste Treatment and Immobilization Plant (WTP). Initially, a modular at-tank cesium removal system will be deployed to provide feed starting with hot commissioning of the WTP LAW facility, which has a targeted completion date of December 2021. The development and testing of this modular at-tank cesium removal system is referred to as the TSCR Demonstration scope. To deploy the

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TSCR system, infrastructure upgrades (including an interim storage pad for spent IXCs, waste transfer lines to and from the TSCR system, and a waste transfer line from the 241-AP tank farm to WTP) are required in and adjacent to the AP Tank Farm. These infrastructure upgrades are managed as a separate set of activities referred to as the DFLAW Feed Delivery Upgrades scope. Collectively, the TSCR Demonstration and the DFLAW Feed Delivery Upgrades are Sub-Project One of the LAWPS Project. In this SDS, “LAWPS Sub-Project One” is synonymous with “Sub-Project One of the LAWPS Project.”

DOE-STD-1189-2008 states that, “Modification projects that require a new or revised hazards/accident analysis or require new hazard controls must be evaluated using the Major Modification Evaluation Criteria to determine if the modification constitutes a ‘major modification’ and requires a PDSA...” As a result of this evaluation, the TSCR Demonstration scope and some of the DFLAW Feed Delivery Upgrades are being implemented as a major modification to the Hanford tank farm DSA (WRPS-1800729, Washington River Protection Solutions LLC Request to Use DOE-STD-3009-94 Change Notice 3 for the Tank Side Cesium Removal Project Major Modification to the Tank Farms Documented Safety Analysis).

Table 1 of the Low-Activity Waste Pretreatment System Preliminary Project Execution Planincludes a description of the TSCR Demonstration scope and DFLAW Feed Delivery Upgrades scope elements. All elements of the TSCR Demonstration scope are part of the tank farm major modification. Elements of the DFLAW Delivery Upgrades scope have been organized into the following groups:

Tank Farm Upgrades to Support TSCR: This group includes design, fabrication, and field work for waste transfer from tanks to TSCR and for waste return, TSCR IXC vent, plant wash, and treated waste from TSCR to tanks; site evaluation, design, construction, and field work of the TSCR IXC storage pad; field work and construction of the TSCR concrete pad; procurement of a forklift for transport of the TSCR IXCs; and other activities necessary to prepare the site for the TSCR facility and activities.

Tank Farm Upgrades to Support Waste Feed from TSCR to WTP: This group includes design, fabrication and field work for the system to transfer waste from the WTP feed tank to the W-211 transfer lines; design, fabrication, and field work for a water flush system servicing the WTP transfer line; and construction acceptance testing of waste transfers from the WTP feed tank to WTP LAW and EMF facilities interface point.

Tank Farm Infrastructure Upgrades to Support TSCR: This group of activities include design, fabrication, installation and field work of tank farm infrastructure; power utility upgrades for increase in change trailer capacity, and revised crane access within the AP tank farm.

With two exceptions, elements of the DFLAW Feed Delivery Upgrades scope are not part of the tank farm major modification. “Fieldwork and construction of the TSCR concrete pad” and “design, construction, and field work of TSCR IXC storage pad” are part of the tank farm major modification.

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This SDS is a summary of the safety basis strategy that will be used to support Sub-Project Oneof the LAWPS Project. This document reflects the safety basis strategy developed as part of the TSCR Demonstration and DFLAW Feed Delivery Upgrades conceptual design. Subsequent revisions to this SDS will be based on a more mature design, the associated Process Hazard Analysis (PrHA) (to be performed according to TFC-ENG- DESIGN- C-47, Process Hazard Analysis), and on control selection activities. For example, a revision of this SDS will be issued to support 90 % design complete (Critical Decision [CD]-2/3). The strategy described in this SDS has been developed to be consistent with the safety strategy in place at the Hanford tank farm.

As indicated in Section 1.0, a PDSA will be developed and included as part of the package submitted to DOE’s Office of River Protection (ORP) at 90 % design complete (CD-2/3). To support the readiness process, an amendment to the tank farm DSA will be developed and the tank farm TSRs will be revised. These safety basis documents will be submitted to ORP for approval to support transition to operations (CD-4). Section 5.1 includes a summary of the nuclear safety documentation associated with each CD step.

2.1 TSCR SYSTEM AND DFLAW FEED DELIVERY UPGRADES OVERVIEW

The DFLAW provides for the early production of immobilized low-activity waste (LAW) by feeding LAW directly from the tank farms into the WTP LAW Vitrification Facility. Prior to the transfer of feed into the WTP LAW Vitrification Facility, the LAW will be pretreated to meet WTP feed waste acceptance criteria (WAC) on maximum cesium-137 (Cs-137) content. During Sub-Project One of the LAWPS Project, this pretreatment will be performed within the TSCR system.

The mission for Sub-Project One of the LAWPS Project is to demonstrate that the technology used in TSCR can 1) prepare treated tank farm supernate LAW for delivery into tank farm double-shelled tanks (DSTs) by removing cesium-137, 2) deliver supernate LAW that meets requirements for direct feed to the WTP LAW facility, and 3) prepare and deliver the supernate LAW in a safe, economic, and environmentally protective manner (RPP-SPEC-61910, Specification for the Tank-Side Cesium Removal Demonstration Project [Project TD101]).

TSCR will pretreat tank farm supernate by removing solids and cesium, using a filtration and ion exchange process. While Sub-Project 2 of the LAWPS Project will include an alternatives analysis to identify the approach for supporting extended DFLAW operations, the scope of the TSCR process is limited to providing WTP with treated supernate until the longer term approachis in place. Two operational phases have been defined for Sub-Project One of the LAWPS Project. In the first, approximately 170,000 gallons of Tank 241-AP-107 waste will be pretreated, and in the second, up to 5,000,000 gallons of additional 241-AP waste will be pretreated.

The TSCR process enclosure will be a temporary structure, located east of the 241-AP tank farm’s southeast corner. The TSCR process enclosure will house filtration units, IXCs, and other process structures, systems, and components (SSCs), all of which are to be designed and installed as part of the TSCR Demonstration. SSCs implemented as part of the DFLAW Feed Delivery Upgrades will include hose-in-hose transfer lines (HIHTLs) (between the TSCR

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process unit and the tank farm), transfer lines between TSCR and WTP, a TSCR control room, heating, ventilation and air conditioning (HVAC) equipment (external to the TSCR process enclosure), support services (e.g., supplies of sodium hydroxide [NaOH], compressed air, and water), and a spent IXC interim storage pad. The vendor specification document (RPP-SPEC-61910) for TSCR includes additional information on the TSCR scope.

The following paragraphs describe the waste delivery and treatment processes associated with the TSCR Demonstration and DFLAW Feed Delivery Upgrades. The process can be summarized as delivery of waste into the TSCR unit, TSCR operations, delivery of the LAW waste stream and other returns into the 241-AP tank farm, spent IXC movement to and storage on the spent IXC interim storage pad, and waste transfers between the 241-AP tank farm and WTP.

Waste will be delivered into the TSCR unit through a transfer line. Similarly, treated LAW will be returned to the 241-AP tank farm through a transfer line. Installation and use of these transfer lines are included within the Sub-Project One scope of the LAWPS Project. Use of these transfer lines will be evaluated in the TSCR PrHAs, control selection, and control development, according to the tank farm PrHA procedure, TFC-ENG-DESIGN-C-47. While the control strategy in the current tank farm safety basis is expected to be sufficient for these transfer lines, if hazards or potential accidents associated with these transfer lines are not adequately covered by the events and controls already in the tank farm safety basis, the events and controls will be identified and developed in the TSCR amendment to the tank farm DSA.

TSCR will pretreat tank farm supernate by removing radioactive cesium using an ion exchange process. Figure 1 is a conceptual system diagram of the TSCR process system as it has been defined for conceptual design (RPP-SPEC-61910). Prior to initiation of the TSCR process, supernate feed (e.g., from Tank 241-AP-107) will be shown to meet the TSCR WAC. The TSCR vendor specification document (RPP-SPEC-61910) includes a description of the expected limiting WAC, e.g., maximum radionuclide content, maximum concentrations of constituents that could promote flammable gas production, and maximum fissile material content.

Tank farm supernate (e.g., from Tank 241-AP-107) will be pumped into the TSCR process unit through an HIHTL. The supernate will be transferred into and through the TSCR processing unit using a tank farm transfer pump. The pump will be sized such that the maximum pressure it can produce in downstream piping will be less than the following:

550 psig in 1-inch diameter piping





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These values were taken from consequence calculations (RPP-CALC-62212) performed for a previous LAWPS facility design; however, results for TSCR are expected to have the same restrictions.

The tank farm supernate will first flow through the TSCR filter unit(s) to remove particulates that are expected to be suspended in the supernate. After flowing through the filter unit(s), the resulting filtered tank farm supernate will flow through IXCs (which will contain the ion exchange medium crystalline silicotitanate [CST]) to remove cesium. The resulting LAW supernate will then flow into a DST (e.g., Tank 241-AP-106) that will be designated as the Interim LAW Storage Tank (ILST) for feed to WTP. The TSCR process will generate effluents, including post-process IXC rinsates, any treated waste that does not meet WTP WAC specifications, e.g, wash effluents, IXC bulk dewater, IXC drying air, and purge nitrogen. These effluents will be transferred into another DST (e.g., Tank 241-AP-108).

As part of normal TSCR operations, processing of the tank farm supernate will be interrupted to allow for routine process support activities. When particulates have collected on the filter media to the extent that the media must be cleaned, flow of the tank farm supernate will be stopped and particulates will be removed from the media, either by backpulsing through the filter media or by a cleaning process to be determined as the TSCR design matures. The resulting particulates will be transferred into a tank farm DST (e.g., Tank 241-AP-108).

In addition, as part of normal TSCR operations, IXCs will routinely need to be replaced. Prior to being replaced, supernate in the loaded IXC will be displaced with dilute NaOH, and the loaded CST in the IXC will then be rinsed, dewatered, and dried. After the IXC is dried, it will be disconnected from the TSCR process system, and filters will be attached to the IXC to provide a filtered vent path for releasing gases generated in the IXC. The IXC will then be transported to the IXC interim storage pad. Other secondary waste streams (e.g., job control waste) will be managed through existing tank farm waste management processes.

IXCs are to be stored on the storage pad in an interim basis, until the final disposal path is defined. A duration for this interim storage has not been defined. In addition, the total number of columns will not be defined until the TSCR design is more mature.

The final operational step associated with the LAWPS Sub-Project One process, is transfer of the LAW supernate from the 241-AP tank farm to the WTP LAW facility and transfer of returns from the WTP EMF to the 241-AP tank farm. Installation and use of the transfer lines associated with these activities are included within the Sub-Project One scope of the LAWPS Project. Use of these transfer lines will be evaluated in the TSCR PrHAs, control selection, and control development, according to the tank farm PrHA procedure, TFC-ENG-DESIGN-C-47. While not expected, if hazards or potential accidents associated with these transfer lines are not adequately covered by the events and controls already in the tank farm safety basis, the events and controls will be identified and developed in the TSCR amendment to the tank farm DSA.

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Figure 1. Tank-Side Cesium Removal Concept System Diagram

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2.2 MAJOR HAZARDS

For TSCR operations, activities associated with the IXC interim storage pad, and movement of spent IXCs to the spent IXC interim storage pad, major hazards and representative accident unmitigated consequence estimations are preliminary estimates based on conceptual designs(e.g., information in the TSCR vendor specification document, RPP-SPEC-61910). For waste transfers, major hazards and representative accident consequences are based on the tank farm DSA (RPP-13033, Tank Farms Documented Safety Analysis).

Major accidents associated with Sub-Project One of the LAWPS Project include fires, waste leaks, misroutes, flammable gas explosions, IXC drops and impacts, and direct radiationexposure scenarios. Table 1 is a summary of the major hazards associated with TSCRoperations, storage of spent IXCs on the spent IXC interim storage pad, and movement of spent IXCs to the spent IXC interim storage pad (i.e., hazards associated with the major modification). Included in Table 1 is 0.1 M sodium hydroxide (NaOH) that will be used in the TSCR process. This reagent will be stored outside of the TSCR enclosure and as needed, will be transferred into the enclosure through piping or tubing. Outside of the enclosure, the hazards associated with reagents will be controlled as part of the tank farm balance of plant.

For waste transfer activities (i.e., delivery of waste into TSCR, returns from TSCR into the AP tank farm, LAW into WTP, and returns from WTP into the AP tank farm), the hazards have been identified in Subsections 3.3.2.1.1.1 (material at risk) and 3.3.2.1.1.2 (energy sources) of the tank farm DSA (RPP-13033). Material at risk includes tank farm waste streams. The hazards associated with the tank farm waste streams are based on radiological and toxicological source terms described in Subsection 3.4.1 of the tank farm DSA. Energy sources associated with the transfer lines include pumps, gravity head, dropped loads, excavation equipment, vehicle impacts, compressed air, flammable liquids, thermal energy, natural phenomena hazards, and external manmade hazards.

Table 2 through 4 are a summary of the representative accidents and controls (including controls necessary to protect assumptions) expected to result from the TSCR operations (including spent IXCs movement to and storage on the spent IXC interim storage pad) PrHAs and control selection. Rather than presenting the major hazards in two separation sections (i.e., identification of the major hazards in Section 2 and consequences in Section 3) as suggested in Appendix E of DOE-STD-1189, the TSCR SDS has been organized to present this information together, in Section 2. Tables 1 through 4, Subsections 2.2 and 2.2.1 through 2.2.3 include these discussions.

Representative accidents and controls associated with waste transfer activities (i.e., delivery of waste into TSCR, returns from TSCR into the AP tank farm, LAW into WTP, and returns from WTP into the AP tank farm) have been summarized in Subsections 3.3.2.3.1 and 3.3.2.4 of the tank farm DSA (RPP-13033) and in Table A03 of the tank farm hazard evaluation database (RPP-15188, Tank Farms Hazard Evaluation Database Report). These representative accidents include waste transfer leaks (described in Subsection 3.3.2.4.3 of the tank farm DSA), air blow accidents (described in Subsection 3.3.2.4.5 of the tank farm DSA), external events (described in Subsection 3.3.2.4.6 of the tank farm DSA), and natural phenomena hazards (described in

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Subsection 3.3.2.4.7 of the tank farm DSA). These representative events have not been included in Table 2 because the associated safety strategy is implemented through the tank farm DSA. The control strategy for each of these will be summarized in the relevant Subsections in Section 3 of this SDS.

As indicated previously, the TSCR and IXC interim storage pad control strategy presented in this SDS is based on preliminary evaluations of the conceptual design (e.g., the TSCR vendor specification document, RPP-SPEC-61910). The control strategy will evolve in response to changes in the design and results from the PrHA, control selection, and control development process. As part of this process, additional administrative controls are expected to be credited with protecting the TSCR facility worker (FWs) (e.g., a specific administrative control [SAC] to ensure sufficient drying air has been passed through an IXC).

Consequences presented in Table 2 are expected to be the bounding unmitigated consequences for similar accident scenarios. For example, “Unmitigated FW consequences: significant” for the fire event indicates the bounding fire event FW consequences could be significant. It is not meant to indicate that the consequences of all TSCR fires would be significant.

The list of hazards presented in Table 1 and potential representative accidents given in Table 2 should not be considered to be an exhaustive list. As indicated in DOE-STD-1189-2008, “An exhaustive list of hazards is not needed; only those that could potentially drive identification of safety class (SC) or safety significant (SS) SSCs need to be listed.” In addition, external manmade events are not expected to require “key safety decisions.” Rather, these strategies are expected to include controls such as bollards and SACs (e.g., traffic controls implemented when certain vulnerable activities are performed). Similarly, events associated with long-term degradation (e.g., long-term effects of weather on the IXCs) have not been included but will be considered as part of the PrHA.

Included in Table 2 are the expected onsite and FW consequences associated with each of these representative accidents. Because preliminary calculations indicate that no TSCR event challenges the public radiological Evaluation Guideline (EG) and no TSCR event exceeds public chemical criteria, no controls are required to be credited for protecting the public. For all representative accidents, the public radiological consequences are less than 5 rem and chemical consequences are less than Protective Action Criteria (PAC)-2 sum-of-fraction criteria.

Table 2 includes an estimate of the seismic design category (SDC) designation and the other natural phenomenon hazard (NPH) design category (NDC) designation associated with each of the safety functions. The methodology used to perform this categorization has been summarized in Subsection 3.3.2.

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Table 1. Major Hazards Associated with TSCR Demonstration and Spent IXC Storage Activities.

Description Hazard Location Quantity Hazard Type

Liquid Process Streams

Tank Farm Supernate (TSCR feed meets the TSCR WAC)

Transfer line into TSCR.

Process unit upstream of the first filter unit inlet.

< 10 gallonsper minute

Rad. (uptake, direct radiation)

Chem. (uptake, chemical burn)

Filter unit. TBD Rad. (uptake, direct radiation)


Filtered Tank Farm Supernate

From filter unit outlet to IXC inlet. < 10 gallons per minute



IXCs. TBD Rad. (uptake, direct radiation)


LAW Supernate (radiological hazard much lower than tank farm supernate, cesium removed)

Process unit downstream of the last IXC outlet.

< 10 gallons per minute



Transfer line into the ILST. < 10 gallons per minute



Filter Unit Solids

Tank Farm Particulates

Filter Unit. TBD Rad. (uptake, direct radiation)

Solids transfer line into returns DST. TBD Rad. (uptake, direct radiation)

CST Cs-137 loaded on CST ion exchange media

TSCR enclosure. 50,000 to 150,000 Ci/column,

3 columns


IXC transport path between the TSCR enclosure and the storage pad.

Spent IXC interim storage pad.

50,000 to 150,000 Ci/column.


Media trap. TBD Rad. (uptake, direct radiation)

Solids transfer line into returns DST. TBD Rad. (uptake, direct radiation)

Reagents(a) 0.1 M NaOH Reagent skid, line to IXC, IXC, line to filter unit(s), filter unit, drain lines from IXC and filter units into returns DST.

TBD Chem. (chemical burn)

Energy Sources

Hydrogen Transfer lines to and from tank farm.

All liquid process stream locations in the process unit.

TBD Potential explosion initiator

Other Energy Sources

Throughout TSCR enclosure TBD Potential accident initiators

Ci = curie.

CST = crystalline silicotitanate.

ILST = Interim LAW Storage Tank.

IXC = ion exchange column.

LAW = low-activity waste.

NaOH = sodium hydroxide.

TBD = to be determined.

(a)Systems that are prevented from containing radioactive material (e.g., reagent storage and handling systems) are not evaluated as part of the Hazard Category 2 process unit, but are considered to be part of the balance of plant (RPP-13033, Tank Farms Documented Safety Analysis, Subsection 3.3.1).

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Table 2. TSCR and Spent IXC Storage Pad Representative Accidents and Safety Significant Controls. (13 sheets)

Representative Accident SS SSC, or SAC

Safety Function Functional Requirement(s) NPH Design Basis

High Radiation Exposure from Fully Loaded IXCs(Subsection 3.3.6 Direct Exposure)

MAR: CST, 150,000 Ci Cs-137(a)

per column, TBD columns on the interim storage pad

Unmitigated frequency: anticipated

Unmitigated onsite consequences:< 5 rem

Unmitigated FW consequences: significant (direct radiation)

IXC Reduce radiation at the outer surface of the IXC.

(credited as SS for protecting FWs)

Required to reduce the radiation at the outer surface of the IXC to an acceptable level. (The acceptable level will be specified in the functional requirements that result from control development.)

SDC-1

Limit State B

NDC-1

Single IXC Drop or Tipover in the TSCR Enclosure, during Transport to the IXC Interim Storage Pad, or on the IXC Interim Storage Pad(Subsection 3.3.6 Direct Exposure)

MAR: CST, 150,000 Ci Cs-137(a)

Unmitigated frequency:

anticipated



IXC Maintain shielding from radiation sources on CST.


Maintain sufficient shielding from radiation sources on CST to reduce the radiation at the column surface to an acceptable level. (The acceptable level will be specified in the functional requirements that result from control development.)

SDC-1

Limit State B

NDC-1

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Misroute ‒ Waste into Interfacing Systems

(Subsection 3.3.6 Direct Exposure)

MAR: Liquid process stream,10 gallons per minute of tank farm supernate (bounding stream), up to 3,000 gal. total (bounding value)

Unmitigated Frequency: anticipated



Double Valve Isolation

Prevent backflow of waste into air system, water system, reagents, or occupied areas.


Required valve configurations will be defined as the TSCR design matures beyond the conceptual phase.

SDC-1,

Limit State C

NDC-1

Misroute ‒ Waste Backflow through Water, Compressed Air, or Other Waste Spill Route(Subsection 3.3.3Loss of Confinement)

MAR: Liquid process stream,

10 gallons per minute of tank farm supernate (bounding stream), up to 3,000 gal. total (bounding value)


Unmitigated onsite consequences:< 5 rem, < PAC-3

Unmitigated FW consequences:significant (radioactive material, chemical burn)

Double Valve Isolation

Prevent backflow of waste into air system, water system, reagents, or occupied areas.


Required valve configurations will be defined as the TSCR design matures beyond the conceptual phase.

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Liquid Process Stream Spray or Leak(Subsection 3.3.3Loss of Confinement)

(Accidents represented by this

event include overpressurization

events. Table 4 includes an

assumption that is the basis for the

maximum process stream pressure

considered).

Unmitigated frequency:

anticipated

Unmitigated onsite consequences:

< 5 rem, < PAC-3

Unmitigated FW consequences: significant(radioactive material, chemical burn)

TSCR EnclosureAccess Controls

Restrict access into areas and rooms in which process equipment is pressurized.

(SAC credited for protecting FWs)

During routine operations, means of entry into the process area are required to be lock closed except when the process system has been isolated from pressure sources (i.e., appropriate valve closed or pump de-energized).

N/A

During offnormal operations (e.g., to repair a component that cannot be shown to be depressurized), entry into the process area is to be restricted to personnel who are protected from the hazards associated with a potential spray.

N/A

TSCR Enclosure

Provides knock-down of processes stream supernate suspended as a spray leak.


Required to prevent large drops of suspended supernate from being released from the enclosure.

SDC-1,

Limit State C

NDC-1

Provides separation between FWs and process equipment that could be in an unsafe configuration (PrHA to identify potentially unsafe configurations).


Required to prevent inadvertent access into the process area for personnel who do not have a key to the personnel entry.

SDC-1,

Limit State C

NDC-1

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Single IXC Drop or Tipover in the TSCR Enclosure, during Transport to the IXC Interim Storage Pad, or on the IXC Interim Storage Pad (Subsection 3.3.3 Loss of Confinement)

MAR: CST, 150,000 Ci Cs-137(a)

Unmitigated Frequency:

anticipated

Unmitigated onsite consequences:> 5 rem, < 100 rem, < PAC-3

Unmitigated FW consequences: significant (radioactive material)

IXC Maintain confinement of ion exchange media.


Required to maintain the credited confinement boundary during and after experiencing an impact (e.g., forklift impact, etc. to be identified as part of the PrHA process) and the forces associated with a subsequent topple.

SDC-2

Limit State B

NDC-2

High-Energy Vehicle Impact with a Single or Multiple IXCsin the TSCR Enclosure, during Transport to the IXC Interim Storage Pad, or on the IXC Interim Storage Pad (Subsection 3.3.3 Loss of Confinement)

MAR: CST, 150,000 Ci Cs-137(a)

per column

Unmitigated Frequency:

anticipated

Unmitigated onsite consequences:> 100 rem, < PAC-3

Unmitigated FW consequences: significant (radioactive material)

Vehicle Barriers (Positioned as Necessary at the TSCR Enclosure and IXC Interim Storage Pad)

Provide a physic barrier to an impact between a vehicle and IXCs.


Required to be located between IXCs in the TSCR enclosure and vehicle traffic capable of resulting in a high-energy impact with any of the IXCs inside the enclosure.

N/A

Required to be located between IXCs on the interim storage pad and vehicle traffic capable of resulting in a high-energy impact with any of the IXCs inside on the storage pad.

Required to be of sufficient construction and sufficiently installed to stop the design-basis vehicle from impacting the IXCs being protected.

Traffic Control SAC

Prohibits vehicles from being in the vicinity of the TSCR enclosure during removal of an IXC and prohibits vehicles from being on the transport path between the TSCR enclosure and the interim storage

During loading of an IXC onto the transport vehicle (expected to be a forklift), vehicle access to the TSCR enclosure and the area used for loading the transport vehicle is required to be limited to vehicles involved in loading of the column onto the transport vehicle.

N/A

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pad. Vehicles involved in the IXC removal and transport are excluded from this prohibition.

During transport of the IXC from the TSCR enclosure, vehicle access between the TSCR enclosure and the interim storage facility, the transport path is required to be limited to vehicles involved in transport of the column.

During off-loading of an IXC onto the interim storage pad, vehicle access to the storage pad and the area used for off-loading of the transport vehicle is required to be limited to vehicles involved in off-loading of the column onto the interim storage pad.

Fire during IXC Transport (Subsection 3.3.4 Fire)

MAR: CST, 150,000 Ci Cs-137(a)



Unmitigated FW consequences: significant (radioactive material, toxic material, direction radiation)

Combustible Material Controls SAC

Limit the quantity of combustible materials (associated with the transport vehicle) to a level that could not support propagation of a fire to the extent that it could compromise the IXC confinement boundary.


TBD based on input from the TSCR fire hazard analyses (could include limiting fuel quantity or type of forklift).

N/A

Traffic Control SAC

Prohibits vehicles from being in the vicinity of the TSCR enclosure during removal of an IXC and prohibits vehicles from being on the transport path between the TSCR enclosure and the interim storage pad. Vehicles involved in the IXC removal and transport are excluded from this prohibition.

During loading of an IXC onto the transport vehicle (expected to be a forklift), vehicle access to the TSCR enclosure and the area used for loading the transport vehicle is required to be limited to vehicles involved in loading of the column onto the transport vehicle.

During transport of the IXC from the TSCR enclosure, vehicle access between the TSCR enclosure and the interim storage facility, the transport path is required to be limited to vehicles involved in transport of the column.

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During off-loading of an IXC onto the interim storage pad, vehicle access to the storage pad and the area used for off-loading of the transport vehicle is required to be limited to vehicles involved in off-loading of the column onto the interim storage pad.

TSCR Enclosure or IXC Storage Pad Fire (Subsection 3.3.4 Fire)

MAR: CST, 150,000 Ci Cs-137(a)

per column, TBD columns on the IXC interim storage pad



Unmitigated FW consequences: significant (radioactive material, toxic material, direction radiation)

Combustible Material Controls SAC

Limit the quantity of combustible materials (on the IXC interim storage pad and in the TSCR enclosure) to a level that could not support propagation of a fire to the extent that it could compromise hazardous material confinement boundaries.


TBD based on input from the TSCR fire hazard analyses.

N/A

Flammable Gas Explosion in IXC (Subsection 3.3.5 Explosion) MAR: CST, 150,000 Ci Cs-137(a), Liquid process stream,

10 gallons per minute of filtered tank farm supernate (bounding stream)

Unmitigated frequency: unlikely


> 5 rem, < 100 rem, < PAC-3

IXC Process Vent

Limit the pressure of accumulated gas in the IXC.


Monitor process stream flow through the IXC. SDC-2,

Limit State C

NDC-2

If an unplanned loss of liquid process stream flow occurs, the IXC process vent is required to establish and maintain an open vent path to the tank farm returns DST.

SDC-2,

Limit State C

NDC-2

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Unmitigated FW consequences: significant (radioactive material, blast pressure, missiles)

Nitrogen Sweep System

Limit the concentration of flammable gas accumulating in the IXC if an unplanned loss of liquid process stream flow occurs.

(credited as SS for protecting FWs).

If an unplanned loss of liquid process stream flow occurs, the nitrogen sweep system is required to establish a nitrogen sweep that is sufficient to maintain flammable gas concentrations below the lower flammability limit (LFL) in the IXC headspace.

SDC-2,

Limit State C

NDC-2

TSCR Process EnclosureAccess Controls

Restrict access to areas and rooms in which process equipment is in a configuration that could accumulate flammable gases.


During routine operations, means of entry into the process area are required to be lock closed except when the process system is in a configuration that will not accumulate flammable gases (e.g., the process system is being swept with nitrogen).

N/A

During offnormal operations (e.g., to repair a component necessary to support nitrogen flow), entry into the process area is to be restricted to personnel who are protected from the hazards associated with the process system configuration.

N/A

TSCR Enclosure

Provides knock-down of processes stream supernate suspended in an explosion.



SDC-1,

Limit State C

NDC-1




SDC-1,

Limit State C

NDC-1

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IXC Filtered Vent

Limit the concentration of flammable gas accumulating in the IXC after the IXC has been disconnected from the TSCR process system.


The IXC filtered vents are required to maintain open vent paths from IXCs that have been disconnected from the TSCR process system.

SDC-2,

Limit State C

NDC-2

High-Temperature, High-Pressure Failure (i.e., “Steam Explosion”) of an IXC (from Cesium-137 Decay Heat) (Subsection 3.3.5 Explosion) MAR: CST, 150,000 Ci Cs-137(a), Liquid process stream,

10 gallons per minute of filtered tank farm supernate (bounding stream)



> 5 rem, < 100 rem, < PAC-3


IXC Process Vent

Limit the pressure in the IXC.


Monitor process stream flow through the IXC. SDC-2,

Limit State C

NDC-2

If an unplanned loss of liquid process stream flow occurs, the IXC process vent is required to establish and maintain an open vent path to the tank farm returns DST.

SDC-2,

Limit State C

NDC-2


Restrict access to areas and rooms in which process equipment is in a configuration that could reach temperatures and pressures that could compromise the IXC.


During routine operations, means of entry into the process area are required to be lock closed except when the process system is in a configuration that would not allow for steam to be generated in the IXC.

N/A


N/A

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TSCR Enclosure

Provides knock-down of processstream supernate suspended in a high-temperature, high-pressure failure of an IXC.



SDC-1,

Limit State C

NDC-1




SDC-1,

Limit State C

NDC-1

IXC Filtered Vent

Limit the pressure of gases that canaccumulate in the IXC after the IXC has been disconnected from the TSCR process system.


The IXC filtered vents are required to maintain open vent paths from IXCs that have been disconnected from the TSCR process system.

SDC-2,

Limit State C

NDC-2

Flammable Gas Explosion in the Filter Unit

(Subsection 3.3.5 Explosion)

MAR: Liquid process stream,

10 gallons per minute of tank farm supernate (bounding stream)



> 5 rem, < 100 rem, < PAC-3

Process Filter Housing

Would not produce shrapnel or missiles upon deflagration of accumulated gas.


Must be constructed such that the housing and tank would not produce shrapnel or missiles upon deflagration of accumulated gas.

N/A

Filter Unit Process Vent

Limit the pressure of accumulated gas in the filter unit.


Monitor process stream flow through the filter unit.

SDC-2,

Limit State C

NDC-2

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In an unplanned loss of liquid process stream flow, the filter unit process vent is required to establish and maintain an open vent path to the tank farm returns DST.

SDC-2,

Limit State C

NDC-2

Nitrogen Sweep System

Limit the concentration of flammable gas accumulating in the in the filter unit if an unplanned loss of liquid process stream flow occurs.

(credited as SS for protecting FWs).

If an unplanned loss of liquid process stream flow occurs, the nitrogen sweep system is required to establish a nitrogen sweep that is sufficient to maintain flammable gas concentrations below the LFL in the IXC headspace.

SDC-2,

Limit State C

NDC-2


Restrict access to areas and rooms in which process equipment is in a configuration that could accumulate flammable gases.



N/A


N/A

TSCR Enclosure

Provides knock-down of processes stream supernate suspended in a flammable gas explosion.



SDC-1,

Limit State C

NDC-1

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SDC-1,

Limit State C

NDC-1

Inadvertent Criticality

(Subsection 3.3.7 Criticality)

MAR: Fissile Material (Pu-239),CST, 150,000 Ci Cs-137(a),10 gallons per minute of tank farm supernate (bounding stream)

Unmitigated frequency: beyond extremely unlikely


Unmitigated FW consequences: significant (radioactive material, direct radiation)

TSCR Waste Acceptance Criteria

(protects initial condition that the TSCR feed meets analyzed fissile material content)

Limit the TSCR feed stream fissile material content to analyzed composition.


Tank farm supernate transferred into TSCR is required to have a fissile material concentration and enrichment that is within the ranges analyzedin the TSCR criticality safety evaluation.

N/A

Natural Phenomena Hazard Events (Subsection 3.3.2 NPH)

MAR: total TSCR and IXC interim storage pad inventory


Unmitigated onsite consequences:> 100 rem (seismic),< 100 rem (other NPH),> 5 rem (other NPH),

IXCs Maintain shielding from radiation sources on CST.


Required to maintain sufficient shielding from radiation sources on CST to reduce the radiation at the outer surface of the IXC to an acceptable level. (Acceptable level to be specified in functional requirements that result from control development.).

SDC-1,

Limit State B

NDC-1

Maintain confinement of ion exchange media.

(credited as SS for protecting onsite and FWs)

Required to maintain the credited confinement boundary (i.e., no breaches large enough to release radioactive CST) during and after experiencing a topple or drop.

SDC-3,

Limit State B

NDC-2

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< PAC-3

Unmitigated FW consequences: significant (radioactive material, chemical burn)

IXC Seismic Restraint

Prevents IXC from impacting the TSCR process enclosure.


Prevents IXC from toppling or sliding, and impacting the TSCR process enclosure during a seismic event.

SDC-2,

Limit State B

TSCR Enclosure

Does not fail in a manner that could compromise the ability of another SS SSC to perform its safety function during and after a seismic event.


For SSCs that are mounted to the enclosure structure above an SS SSC, the mounting is required to prevent the mounted SSC from impacting the SS SSC. This is commonly preferred to as a control topography or 2-over-1 concern.

SDC-1,

Limit State C

Provides knock-down of processes stream supernate suspended as a spray leak.


Required to maintain sufficient integrity in a seismic event that any breaches would be too small to allow for a release of large drops of suspended supernate.

SDC-1,

Limit State C

Provides separation between FWs and process equipment that could be in an unsafe configuration (PrHA to identify potentially unsafe configurations that might occur as a result of a seismic event).



SDC-1,

Limit State C

Provides barrier against NPH stresses that could compromise the ability of SS SSCs to perform its safety function during and after anNPH event.

Required to maintain its integrity under stresses associated with applicable NPH events (e.g., protect against wind driven missiles, maintain integrity under design-basis rain, snow and ash-loading, etc, as determined by PrHA).

NDC-1

Limit State B

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Restrict access into areas and rooms in which process equipment is in an unsafe configuration (PrHA to identify potentially unsafe configurations that might occur as a result of a seismic event).



N/A

During offnormal operations (e.g., to repair an SSC that cannot be shown to be depressurized), entry into the process area is to be restricted to personnel who are protected from the hazards associated with potentially compromised SSCs.

N/A

TBD

(FWs will be protected by seismic criteria associated with controls and safety functions previously identified for operational events)

TBD


TBD TBD

(a) This is an initial condition that is protected by the TSCR waste acceptance criteria as indicated in Table 4. This value (150,000 Ci) is based on the amount of CST that could be in an IXC, the assumption that the CST is fully loaded during processing, and the limiting attributes of the feed stream, such as total cesium content, ratio of cesium-137 to total cesium, and concentrations of other constituents in the TSCR feed.

FW = facility worker.

IXC = ion-exchange column.

NDC = Natural Phenomena Design Category.

PAC = Protective Action Criteria.

SAC = specific administrative control.

SDC = Seismic Design Category.

SS = safety-significant.

SSC = structure, systems, and components.

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Table 3. *Key Tank-Side Cesium Removal Safety-Significant Support and Interfacing Systems.

SS Support System SS SSC, or SACSupported

Support System Safety Function Support System Functional Requirement(s)

NPH Design Basis

Process Enclosure All SS SSCs within the process enclosure.

Prevent interactions with SS SSCs during design basis NPH events that could degrade the supported system’s safety function.

Protect the safety function of SS SSCs during high-wind, seismic, rainfall, snowfall, and ash-fall events.

SDC-2,

Limit State B

NDC-2

External Support Skids and Structures (to be identifiedduring PrHA)

TSCR process enclosure and SS SSC within the process enclosure.

Prevent interactions with SS SSCs during design basis NPH events that could degrade the supported system’s safety function.

Protect the safety function of SS SSCs during high-wind, seismic, rainfall, snowfall, and ash-fall events.

SDC-2,

Limit State B

NDC-2

*This table is not an exhaustive list of support and interfacing systems. Additional support systems and interfacing systems are expected to be identified during the PrHA process.

Table 4. Tank-Side Cesium Removal Initial Conditions and Other Assumptions Considered for Protection.

Assumption SS SSC, or SAC Safety Function Functional Requirement(s)

Flammable gas generation rate in IXC (IXC flammable gas removal system safety timer duration)


Prevent the accumulation of Cs-137within an IXC in excess of analyzed values.

For tank farm supernate transferred into TSCR, the ratio of Cs-137to nonradioactive cesium must be below the value that would limit Cs-137 on the CST media to values less than or equal to that used as the basis for hydrogen generation rates and accident analyses.

Unit dose values used in accident analysis (IXC)

Fissile material content used in criticality safety evaluation


Limit the TSCR feed stream fissile material content to analyzed composition.

Tank farm supernate transferred into TSCR is required to have a fissile material concentration and enrichment within ranges analyzed in the TSCR criticality safety evaluation.

Maximum liquid process stream pressure (TSCR design is such that any process stream spray leak would have low consequences to the onsite worker)

N/A N/A N/A

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2.2.1 Hazards to the Public

No events pose an offsite radiological or offsite toxicological hazard.

2.2.2 Hazards to Onsite Workers

The unmitigated seismic event included in Table 2 and discussed in Subsection 3.3.2 is expected to have the potential for significant onsite worker consequences (i.e., unmitigated radiological consequences could be higher than 100 rem). In the unmitigated scenario associated with the design-basis seismic event, CST loaded with Cs-137 could be released from multiple IXCs (containing fully loaded, dewatered, and dried CST) on the IXC interim storage pad. In additionto the control (SS IXCs) for this event, some aspects of the WAC protect initial conditions (shown in Table 4) that are the bases for evaluating the onsite worker consequences.

In addition, high-energy impact events in which loaded IXCs (e.g., impact of a vehicle traveling at a relatively high speed) could have the potential for significant onsite worker consequences. This event has also been included in Table 2 and discussed in Subsection 3.3.3. Other manmade external events have not been included in this SDS. These manmade external events will be evaluated as part of a TSCR PrHA. These events are not expected to require additional controls or analyses beyond those already described in the Tank Farm DSA (e.g., aircraft crash analyses).

2.2.3 Hazards to Facility Workers

Potential representative accidents that might present significant FW consequences have beenidentified in Table 2 for TSCR operations and activities associated with the spent IXC storage pad. A comprehensive list of representative accidents will be generated during future PrHA, control selection, and control development activities. The purpose of the information given in Table 2 is to provide sufficient information to allow for the Section 3.3 discussions of the key safety decisions.

For waste transfer activities (i.e., delivery of waste into TSCR, returns from TSCR into the AP tank farm, LAW into WTP, and returns from WTP into the AP tank farm), representative accidents that might present significant FW consequences and controls associated with these accidents have been summarized in Subsections 3.3.2.3.1 and 3.3.2.4 of the tank farm DSA (RPP-13033), and in Tables A 03 and B 03 of the tank farm hazard evaluation database (RPP-15188). These representative accidents include waste transfer leaks (described in Subsection 3.3.2.4.3 of the tank farm DSA), air blow accidents (described in Subsection 3.3.2.4.5 of the tank farm DSA), external events (described in Subsection 3.3.2.4.6 of the tank farm DSA), and natural phenomena hazards (described in Subsection 3.3.2.4.7 of the tank farm DSA). These representative events have not been included in Table 2 because the associated safety strategy isalready implemented through the tank farm DSA. The control strategy for each of these will be summarized in the relevant Subsections in Section 3 of this SDS.

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3.0 SAFETY STRATEGY

As indicated in DOE-STD-1189-2008, Section 3.0 of the SDS “should present the overall safety strategy for the project.” The following subsections are a summary of the safety strategy for Sub-Project One of the LAWPS Project. For TSCR operations, movement of spent IXCs to the spent IXC storage pad, and storage of the IXCs on the spent IXC storage pad, this information is based on preliminary hazard evaluations. Because this SDS is part of the conceptual design development, controls for these activities have not been fully developed. While the safety strategy is not expected to change drastically, safety functions and functional requirements will be refined during control development.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the safety strategy for Sub-Project One of the LAWPS Project is based on the safety strategy that is in place for tank farm waste transfers (RPP-13033).

3.1 SAFETY GUIDANCE AND REQUIREMENTS

This section presents the overarching philosophies and goals for addressing the hazards involved in Sub-Project One of the LAWPS Project. Sub-Project One of the LAWPS Project isconsidered to be within the scope of the Hanford tank farms authorization basis. As such, for hazards, events, and controls specific to Sub-Project One of the LAWPS Project (i.e., those not in the current tank farm DSA), they will be documented in an addendum to the tank farm DSA (RPP-13033) and will be added to the tank farm TSRs document (HNF-SD-WM-TSR-006, Rev. 8-C, Tank Farms Technical Safety Requirements).

3.1.1 Safety-in-Design Approach

Sub-Project One of the LAWPS Project is integrating safety-in-design by following the guidance in DOE-STD-1189-2008, including safety design guiding principles (e.g., control selection strategy follows the order of preference including reducing hazardous materials as the first priority; SSCs are preferred over administrative controls; passive SSCs are preferred over active SSCs; preventive controls are preferred over mitigative controls; controls closest to the hazard are considered to provide protection to the largest population of potential receptors, including FWs, onsite workers, and the public).

No hazard associated with Sub-Project One of the LAWPS Project will challenge the EG for exposure of the public to radioactive material, and no hazard will challenge the criteria for exposure of the public to toxic material. Using a control selection process that includes the order of preference described in the previous paragraph, onsite workers and FWs will be protected from potentially significant consequences associated with unmitigated releases of radioactive and other hazardous materials. These controls were functionally classified using the protocoldescribed in Section 3.2.

Although engineered controls are generally preferred over administrative controls, in some events, administrative controls were determined to be more effective than engineered controls. In these events, the upset condition would be slow developing and easily identified, and the

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operator would have an abundance of time to take the appropriate action to prevent the event, or the operator action is taken pre-emptively (i.e., the action is taken to establish a safe configuration before the upset could occur). In these cases, the more effective administrative features have been or will be (i.e., during the PrHA and control selection process) identified as a SAC.

3.1.2 Safety Functional Classification

The functional classification of SSCs is based on the methodology and criteria described in DOE-STD-1189-2008, Appendices A through D as augmented by Hader (2014), Revision on Direction to Implement New Safety Classification Process for the Tank Farms and 242-A Evaporator Documented Safety Analyses and New Capital Projects. Hader (2014) specifies the methodologies and guidelines to be applied to the major preventive and mitigative SSCs that are selected from the analyses of the representative accidents. The guidelines are summarized in Table 5. According to these criteria, support systems that are essential for an SC or SS SSC to perform its safety function are to be classified at the same level as the supported SSC.

Public and onsite worker potential unmitigated consequences concluded that no accidentassociated with Sub-Project One of the LAWPS Project would challenge the offsite EG (i.e., >5 rem), and therefore, no SSC will be classified as SC. In addition, evaluations indicate that no public toxic material evaluation criteria (i.e., > PAC-2) is exceeded, and therefore, for Sub-Project One of the LAWPS Project, no SSC will be classified as SS for protecting the public.

In addition, preliminary design scoping evaluations indicate that unmitigated onsite consequences would be less than 100 rem and less than PAC-3, except for the design basis seismic event (which could have onsite consequences greater than 100 rem due to the release of loaded CST from multiple compromised IXCs on the spent IXC interim storage pad) and potentially for some high-energy IXC impact events (which could also have onsite consequences greater than 100 rem). To protect the onsite worker in the design-basis seismic event, the control strategy was developed by applying the hierarchy of controls summarized in Subsection 3.1.1. Table 2 and Subsection 3.3.1 include a summary of the resulting control strategy.

To protect FWs, preventive and mitigative SSCs were selected by evaluating the representative accidents and applying the hierarchy of controls summarized in Subsection 3.1.1. SACs and SSSSCs were first identified by evaluating operational accidents. To protect FWs in NPH events, these controls were considered and the appropriate functional requirements and performance criteria were identified to ensure the control would perform its safety function in the applicable NPH events. With the exception of high-energy impacts, manmade external events have not been included in this SDS. These will be evaluated as part of a PrHA for Sub-Project One of the LAWPS Project. These events are not expected to require additional controls beyond the need for vehicle barriers (e.g., “Jersey” barriers or bollards), vehicle speed controls and administrative controls.

During the PrHA, the PrHA team members are likely to identify accident scenarios that are below consequences requiring safety-significant controls. These scenarios will be documented for the personnel to address appropriately. For example, descriptions of fire events will be available for consideration in the TSCR Fire Hazard Analysis regardless of whether the

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consequences are sufficient to require SACs or safety significant SSCs. If an accident scenario could result in a release of low levels of radioactive material (i.e., low consequences to the public, onsite workers, and FWs), a description of this event will be available for consideration in the Radiological Protection Program. If an accident scenario could result in a release of low levels of a toxic material (i.e., low consequences to the public, onsite workers, and FWs), or could result in a physical consequence that is controlled in the tank farm by implementation of an industry code or standard, a description of this event will be available for consideration by Industrial Hygiene and Industrial Safety Personnel.

Table 5. Safety Classification Guidelines.

Offsite Public Onsite Worker Facility Worker

≥ 25 rem TED

Safety-Class SSCs or TSRs (SACs) are required

≥ 100 rem TED or > PAC-3

SS SSCs or TSRs (SACs) are required

All FW hazards are assessed for prompt death or serious injury or significant radiological or chemical exposure.≥ 5 rem TED to < 25 rem TED

Safety-Class SSCs or TSRs (SACs) are considered

≥ 0.1 rem TED to < 5 rem TED

To assist in the determination of sufficient defense-in-depth, this range provides a perspective for consideration to be discussed between the TOC and ORP

≥ 5 rem TED to < 100 rem TED

To assist in the determination of sufficient defense-in-depth, this range provides a perspective for consideration to be discussed between the TOC and ORP

> PAC-2

SS SSCs or TSRs (SACs) are required

ORP = Office of River Protection.

PAC = Protective Action Criteria.


SSC = structures, systems, and components.

TED = total effective dose.

TOC = Tank Operations Contractor.

TSR = technical safety requirement.

3.1.3 Safety Design Criteria

Safety design criteria for LAWPS Sub-Project One include the safety design criteria described in DOE O 420.1C, Change 1, Facility Safety.

Nuclear and Explosives Safety Design Criteria (Attachment 2, Chapter I) Fire Protection (Attachment 2, Chapter II); Nuclear Criticality Safety (Attachment 2, Chapter III); Natural Phenomena Hazards Mitigation (Attachment 2, Chapter IV); and Design Criteria for Safety Structures, Systems, and Components (Attachment 3).

In addition, the following contain specific criteria or guidance for implementing these requirements.

DOE G 420.1-1A, Nonreactor Nuclear Safety Design Guide for use with DOE O 420.1CFacility Safety;

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DOE-STD-1066-2012, DOE Standard ‒ Fire Protection;

DOE-STD-3007-2007, DOE Standard ‒ Guidelines for Preparing Criticality Safety Evaluations at Department of Energy Nonreactor Nuclear Facilities;

DOE-STD-1020-2012, DOE Standard ‒ Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities;

DOE-STD-1189-2008, Integration of Safety into the Design Process; and

DOE-STD-3009-94, Change Notice No. 3, DOE Standard ‒ Preparation of Nonreactor Nuclear Facility Documented Safety Analyses.

Although Sub-Project One of the LAWPS Project is following the requirements of DOE-STD-1189-2008, which specifies DOE O 240.1B, Sub-Project One of the LAWPS Project is being performed to DOE O 420.1C. In addition, the safety basis documentation is to be prepared according to DOE-STD-3009-94, Change Notice No. 3 [Harp 2018].

Alternative safety design criteria approved by DOE-ORP include the following alternate design criteria:

ANSI/ISA-84.00.01-2004 in lieu of DOE-STD-1195-2011 [Hader and Smith 2016]

This strategy includes use of ANSI/ISA-84.00.01-2004, Functional Safety: Safety Instrumented Systems for the Process Industry Sector, in lieu of DOE-STD-1195-2011, Design of Safety Significant Safety Instrumented Systems Used at DOE Nonreactor Nuclear Facilities. This strategy is consistent with the Hanford tank farm safety basis.

Specific design codes and standards to be used for the design of the safety SSCs will be identified in the code of record that will be established as Sub-Project One of the LAWPS Project matures.

The project has not identified any exemptions to DOE O 420.1C requirements and criteria.

Potential public and onsite worker consequences are based on dose coefficients fromInternational Commission on Radiological Protection Publication 68, Dose Coefficients for Intakes of Radionuclides by Workers, and Publication 72, Age-dependent Doses to Members of the Public from Intake of Radionuclides for Adults. For Cs-137, ICRP 68 only contains dose coefficients that would be applicable if the Cs-137 were in a soluble cesium form (i.e., one that is easily excreted from the body). Because cesium adsorbed on CST is not a soluble form, using the ICRP 68 coefficients is not conservative. Therefore, for calculating the dose associated with inhalation or ingestion of loaded CST, the ICRP 72 Type S dose coefficients were used. For calculating the dose associated with inhalation or ingestion of other forms of cesium (e.g., the liquid process stream), the ICRP 68 dose factors were used.

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3.2 HAZARD IDENTIFICATION

This section is a summary of the major hazards associated with Sub-Project One of the LAWPS Project. For TSCR operations and activities associated with the spent IXC storage pad, Table 2 includes a summary of consequence levels from a preliminary evaluation of these hazards and the accident scenarios in which the hazardous material is released or otherwise impacts personnel. Potential inventory values (Table 1) have been based on preliminary conservative estimates of the TSCR process and feed material.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), this information has been well documented in the tank farm hazard evaluation data base (RPP-15188) and DSA (RPP-13033). This SDS includes a summary of the appropriate information (e.g., representative events, SS controls, and hazards) and references to the appropriate sections or subsections of the tank farm database report and DSA.

Rather than presenting the major hazards in two separate sections (i.e., identification of the major hazards in Section 2 and discussion of inventories and consequences in Section 3) as suggested in Appendix E of DOE-STD-1189-2008, the LAWPS Sub-Project One SDS has been organized to present this information together, in Section 2. Tables 1 and 2, and Subsections 2.2 and 2.2.1 through 2.2.3 include these discussions.

Preliminary categorization of TSCR indicated that based on the bounding Cs-137 inventory, the TSCR unit is to be Hazard Category (HC)-2. The HC-2 threshold for Cs-137 is 89,000 Ci (DOE-STD-1027-92, Attachment 1). This HC-2 threshold value could be exceeded by a single IXC loaded to the potential maximum IXC capacity, 150,000 Ci (Table 1).

3.3 KEY SAFETY DECISIONS

This section is a summary of the key safety decisions associated with the systems and processesin Sub-Project One of the LAWPS Project. These are decisions that could result in significant cost or have resulted in costly rework in past projects. This summary includes sufficient detail to justify the control strategy and establish how the strategy protects personnel from potential hazardous accident scenarios.

As indicated in previous sections of this SDS, key safety strategy decisions associated with Sub-Project One of the LAWPS Project are those associated with TSCR operations and activities associated with the spent IXC storage pad. For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW to WTP, and receipt of returns from WTP into the AP tank farm), safety strategy decisions have largely been addressed by application of the tank farm control strategy already implemented and described in the tank farm DSA (RPP-13033). This section includes a summary of this control strategy and a reference to the applicable section or subsection of the tank farm DSA or hazard evaluation data base (RPP-15188).

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3.3.1 Anticipated Safety Functions

For TSCR operations and activities associated with the spent IXC storage pad, the preliminary design solution (SSC or SAC), safety functions, safety functional classification, and functional requirements are included in Table 2 and 3. For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), this information is provided in the Section 2 text and references and in the following subsections.

As discussed in Subsection 2.2, no events are expected to challenge the public EG. Therefore, for Sub-Project One of the LAWPS Project, no SSC is classified as SC. The following subsections include a description of the control strategy including a summary of the key support systems and the controls that are supported by these systems.

The control strategies described in the following subsections are based on the potential consequences that could result from the unmitigated representative accident scenarios. For representative accidents in which the MAR includes one of the liquid process streams (i.e., tank farm supernate, filtered tank farm supernate, or the TSCR LAW supernate product), the composition of the MAR is based on a conservative assumption of the tank farm supernate composition. As indicated in Table 4, this initial condition is protected by the TSCR waste acceptance criteria SAC. Because this initial condition is the basis for calculations that show the onsite consequences to be low for operational events, this SAC should be considered to protect both the onsite workers and FWs.

The following subsections contain a high-level summary of the control strategy for the representative accidents identified in Table 2 and representative waste transfer accidents presented in the tank farm DSA (RPP-13033) and data base (RPP-15188). Safety functions and functional requirements identified in Tables 2 through 4 are based on preliminary assessments of the conceptual designs. Changes to these safety functions, functional requirements and representative accidents are expected as the design matures. Safety functions, functional requirements and representative accidents identified in the tank farm DSA and data base are not expected to change substantially.

3.3.2 Seismic and Other Natural Phenomena Design Categorization

Natural phenomena hazards have the potential to initiate accidents that could have multiple releases. Although NPH events could include multiple releases, each release is similar to a release that has been evaluated as part of an operational event. Therefore, the potential consequences of an NPH event is the sum of the potential consequences of the corresponding operational events. Similarly, the credited controls for the NPH event are the same controls credited in the operational events with additional performance criteria required to support the need to perform the safety functions during the NPH event. NPH events that are expected to require SS controls include seismic, high-wind, snow-loading, ashfall, and rainfall events. Other NPH events that will be considered during the PrHA and control selection process include high and low-temperature extremes, flooding, range fires, and lightning.

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For each NPH event, the appropriate design category is determined by the potential onsite and FW consequences of the event. The criteria and guidance for the analysis and design of SSCs for NPH events are provided in DOE-STD-1189-2008 and DOE-STD-1020-2012. For Sub-Project One of the LAWPS Project, because no accident challenges the public EG, no LAWPS Sub-Project One SSC is required to meet NDC-4 or NDC-5 criteria.

For an SS SSC that is credited with protecting the FWs in an NPH event, if the NPH event could cause a failure of the control and if the consequences of that failure could be greater than 100rem to the onsite worker, the SS SSC is required to meet the applicable NDC-3 criteria (e.g., SDC-3 for a seismic event).

Similarly, if the NPH event could cause a failure of the control and if the consequences of that failure could be greater than 5 rem or greater than PAC-2 to the onsite worker but could not be greater than 100 rem to the onsite worker, the SS SSC is required to meet the applicable NDC-2 criteria (e.g., SDC-2 for a seismic event).

If the NPH event could cause a failure of the control but the consequences of that failure could not be greater than 5 rem to the onsite worker and would not be greater than PAC-2 to the onsite worker, the SS SSC is required to meet the applicable NDC-1 criteria (e.g., SDC-1 for a seismic event).

As indicated in previous sections of this SDS, preliminary evaluations concluded that no accident(including NPH accidents) would challenge the offsite EG (i.e., > 5 rem), and therefore, for Sub-Project One of the LAWPS Project, no SSC will be classified as SC. In addition, these evaluations indicate that no public toxic material evaluation criteria (i.e., > PAC-2) is exceeded, and therefore, for Sub-Project One of the LAWPS Project, no SSC will be classified as SS for protecting the public.

Preliminary determinations indicate that the design basis seismic event has the potential toexceed the radiological evaluation criteria for onsite workers. In this event, consequences associated with sprays (including sprays from a failed transfer line) do not have the potential to exceed exposure criteria for the onsite workers. Loss of loaded CST confinement from multiple spent IXCs on the storage pad has the potential to provide a large majority of the onsite workerradiological consequences for this event. Onsite worker chemical consequences would not exceed onsite worker evaluation criteria.

Preliminary calculations indicate consequences associated with some unmitigated NPH events could have significant radiological and toxicological consequences to FWs.

As indicated in Table 2, for TSCR operations and activities associated with the spent IXC storage pad, the control strategy for these events includes crediting (as SACs or SS SSCs) the following controls:

IXCs are SS SSCs credited with providing confinement of the radioactive CST during seismic and other NPH events. The IXCs will be required to meet SDC-3 criteria for CST confinement and SDC-1 criteria for shielding during a seismic event. For other NPH events for which the IXCs are credited (to be identified as part of the TSCR PrHA), the

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IXCs could be required to meet NDC-2 criteria for providing confinement. This is expected to be particularly true when IXCs are located on the storage pad.

IXC seismic restraints are SS SSCs credited with preventing the IXC from impacting and breaching the TSCR enclosure structure during a seismic event. The IXC seismic restraints will be required to meet SDC-2 criteria for preventing the IXC from impacting the TSCR enclosure structure.

The TSCR enclosure structure is an SS SSC credited with protecting the FWs by performing the safety functions listed in Table 2. Depending on the safety function, the TSCR structure will be required to meet SDC-1 or SDC-2, and NDC-1 or NDC-2 criteria.

TSCR process enclosure access controls are a SAC credited with preventing inadvertent access into the enclosure unless the TSCR processing system has been verified to be in a configuration that is compatible with entry.

As part of the TSCR PrHA, other SS SSCs are expected to be credited with providing FW protection in NPH events. Table 2 provides an indication of the design categorization that would be applicable for each of the SSCs if it is identified as requiring design categorization of an NPH event.

The spent IXC interim storage pad provides defense-in-depth protection for supporting safe storage of spent IXCs. Because the SS IXCs would provide sufficient protection if the storage pad were to fail, the storage pad provides an additional layer of protection, but is not required to be SS.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the control strategy described in the tank farm DSA is expected to be sufficient to protect workers in events associated with these activities. The control strategy for these events is described in Subsections 3.3.2.4.3 and 3.3.2.4.7 of the tank farm DSA (RPP-13033) and in Tables A 06 and B 06 of the tank farm data base report (RPP-15188). This strategy includes crediting (as SS SSCs) the following controls: the waste primary piping systems and the HIHTL primary hose assemblies. In addition, the safety strategy includes key elements of the Emergency Preparedness SMP as described in Subsections 3.3.2.4.7 and 5.5.3.6 of the tank farm DSA.

3.3.3 Confinement Strategy

Preliminary calculations indicate that no operational accident could result in consequences that would exceed public or onsite worker radiological or chemical evaluation criteria. In addition, one external manmade event (a high-energy vehicle impact with an IXC) could have significant onsite worker radiological consequences.

Preliminary evaluations also indicate consequences associated with some unmitigated loss-of-confinement scenarios could have significant radiological and toxicological consequences to FWs. For spray and leak events, the chemical consequences are expected to be more significant

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than the radiological consequences. This is particularly true when considering in the unmitigated scenarios, FWs would take self-protective actions if exposed to a large spray or leak from the process stream. As indicated in Table 2, for TSCR operations and activities associated with the spent IXC storage pad, the control strategy for these events includes crediting (as SACs or SSSSCs) the following controls:

Double valve isolation SSCs are SS, credited with providing protection against misrouting one of the liquid process streams (tank farm supernate, filtered tank farm supernate, or the LAW supernate product) into one of the utility systems, where the misrouted process stream could fail the general services confinement boundary (e.g., by exceeding the pressure or temperature of a seal or introduction of an incompatible process stream) resulting in a release of the process stream. In a similar representative accident, a liquid process stream misroute that does not fail the confinement boundary could result in a direct exposure event. Subsection 3.3.7 includes a summary of the direct exposure accident.

The TSCR enclosure structure is an SS SSC credited with protecting the FWs from the consequences of an unmitigated spray or spill accident. The TSCR enclosure structure provides this protection by performing the safety functions listed in Table 2. In addition to preventing FWs from being in the immediate vicinity of a potential spray release, the enclosure structure must act to knock-down large drops of aerosolized supernate.

IXCs are SS SSCs credited with providing confinement of the radioactive CST during impact, topple, and drop events.

Vehicle barriers are SS SSCs credited with providing a physical barrier to a high-energy impact of a vehicle with an IXC inside the TSCR enclosure and with an IXC on the interim storage pad.

TSCR process enclosure access controls are a SAC credited with preventing access into the enclosure unless the TSCR processing system has been verified to be in a configuration that is compatible with entry.

Traffic controls are a SAC credited with prohibiting vehicles from the vicinity of IXCs during vulnerable activities (i.e., activities in which vehicle barriers would not provide the necessary protection (e.g., during transport of an IXC).

In addition to the SS controls outlined in the previous paragraph, the TSCR confinement strategy includes features that are not credited as SS. For example, except for the IXC, the primary confinement of the process system (including the filter units) provides defense-in-depth protection against loss of confinement scenarios. The pressures associated with the TSCR process are sufficiently low that they do not pose an onsite spray leak hazard.

Secondary confinement (including active ventilation for the process enclosure) is another defense-in-depth feature of the TSCR unit.

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The ventilation system is not expected to be a credited SS control, nor is it expected to be identified as an SS major contributor to defense-in-depth. While the ventilation will provide filtration and differential pressure (cascade airflows), both of which prevent the spread of contamination, the credited SS SSCs (identified in Table 2) and the access controls SAC are a more effective strategy for reducing the risk associated with the TSCR unmitigated scenarios. Appendix A is a summary of a TSCR confinement strategy evaluation.

Until TSCR PrHA meetings have been held, detailed accident scenarios for the optimized TSCR design will not be developed. Therefore, conservative assumptions have been used in the evaluations summarized in Table 2. For example, until potential misroute scenarios have been identified, consequences have been based on very conservative assumptions as to the quantity of tank farm supernate that can be transferred as a result of the misroute upset condition.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the control strategy described in the tank farm DSA is expected to be sufficient to protect workers in events associated with these activities. The control strategy for these events is described in Subsection 3.3.2.4.3 of the tank farm DSA (RPP-13033) and in Tables A 06 and B 06 of the tank farm data base report (RPP-15188). This strategy includes crediting (as SS SSCs) the following controls: the waste transfer primary piping systems, HIHTL primary hose assemblies, isolation valves for double valve isolation and as an important contributor to defense-in-depth, HIHTL encasement hose assemblies. The safety strategy also includes a SAC to ensure double valve isolation is in the appropriate configuration. In addition, the tank farm safety strategy includes an administrative control key element, waste transfer-associated structure cover installation and door closure, and includes the waste leak evaluation program.

3.3.4 Fire Mitigation Strategy

Preliminary calculations indicate that no operational accident could result in consequences that would exceed onsite worker radiological or chemical evaluation criteria. Preliminary evaluationsalso indicate consequences associated with some unmitigated fire events could have significant radiological and toxicological consequences to FWs. As indicated in Table 2, for TSCR operations and activities associated with the spent IXC storage pad, the control strategy for these events includes crediting combustible material controls (including a SAC for limits specific to TSCR) and traffic controls to protect FWs from the consequences of unmitigated fire scenarios.

In addition to the combustible material controls SAC and the traffic control SAC, the fire mitigation strategy includes features that are not credited as SACs or as SS SSCs. The TSCR unit will be designed and constructed in accordance with applicable provisions of DOE-STD-1066-2012 and MGT-ENG-IP-05, Fire Protection Program. The process unit will be operated within established Tank Operations Contractor (TOC) fire protection program standards, which will ensure limited combustible loading, control of ignition sources, and thorough understanding of fire risks via a formal Fire Hazards Analysis.

As the design matures, an FHA and PrHA will be performed. These activities will document sources of combustible and flammable material, significant fire scenarios, and important attributes of the combustible material controls SAC. Subsequent control selection and control

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development activities will determine whether additional controls need to be credited to adequately control these fire scenarios.

As part of the FHA, PrHA, control selection, and control development activities, credited controls will be evaluated to ensure a fire cannot initiate an accident while simultaneously disabling the safety system credited to prevent or mitigate that event. For passive SSCs (e.g., IXCs), this evaluation is expected to focus on the combustible material controls SAC to ensure the control is sufficient to prevent the initiation of a loss-of-confinement or loss-of-shielding (i.e., direct exposure) event caused by a fire.

As part of the control development for SACs and active SSCs, the evaluation might consider whether the system design needs to ensure the processing unit can be placed into a safe state in the event of a credible fire scenario. If, after crediting the combustible material controls SAC, the fire could still prevent effective implementation of a SAC or if the fire could still impede an active SSC from transitioning into the system’s safe state, additional controls or performance criteria for existing controls will be identified.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the control strategy described in the tank farm DSA is expected to be sufficient to protect workers in events associated with these activities. The control strategy for these events is described in Subsections 3.3.2.4.3 and 5.5.3.6 of the tank farm DSA (RPP-13033) and in Tables A 06 and B 06 of the tank farm data base report (RPP-15188). This strategy includes key elements of the Emergency Preparedness SMP to terminate waste transfers in response to off-normal conditions that could fail waste transfer components.

3.3.5 Flammable Gas Control Strategy

Preliminary calculations indicate that no operational accident could result in consequences that would exceed public or onsite worker radiological or chemical evaluation criteria. Preliminary evaluations also indicate consequences associated with some unmitigated flammable gas explosion events could have significant radiological and toxicological consequences to FWs.

For TSCR operations and activities associated with the spent IXC storage pad, the flammable gas control strategy will be developed as the TSCR design matures and a PrHA has been completed. The control strategy is expected to be 1) to keep flammable gases dissolved in the liquid process stream, 2) when gas is present in the system, to vent or purge the system, and 3) protect personnel and SS SSCs (e.g., by access controls and using materials of construction that do not produce shrapnel in a failure scenario). While access controls protect FWs during processing of tank farm supernate, additional controls are expected to be necessary to establish and maintain conditions that will prevent accumulation of flammable gas when personnel are in the enclosure and when an IXC is disconnected from the TSCR process unit (e.g., controls to ensure IXCs have been sufficiently dewatered and dried prior to disconnection of the IXC from the TSCR process unit, and a vent path on the disconnected IXC).

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Ignition controls also provide protection from these events. During control selection, a determination will be made as to whether attributes of these controls need to be credited as an SAC or identified as key elements of the Fire Protection Program.

Table 2 includes a high-temperature, high-pressure failure caused by Cs-137 decay heat. The control strategy for this event is similar to the control strategy for some flammable gas explosion events. In this scenario, liquid is present in the IXC. While preliminary evaluations indicate that this scenario could not occur in the proposed IXC design and tank farm supernate feed streams, the TSCR PrHA will evaluate IXC thermal failure scenarios associated with Cs-137 decay heat.

As indicated in Table 2, the control strategy for TSCR operations and activities associated with the spent IXC storage pad is expected to include crediting (as SACs or SS SSCs) the following controls:

The IXC process vent is an SS SSC that is expected to be credited with being opened upon loss of process stream flow. The configuration of this control will be developed as the TSCR design matures.

The filter unit process vent is an SS SSC that is expected to be credited with being opened upon loss of process stream flow. The configuration of this control will be developed as the TSCR design matures.

An air sweep system will provide flow to remove flammable gases from IXC and filter unit. The need for this system will be determined during the TSCR PrHA.

IXC filtered vents are expected to be credited with maintaining a vent path from the loaded, dewatered and dried IXCs.

TSCR process enclosure access controls are a SAC expected to be credited with preventing inadvertent access into the enclosure when the potential exists for flammable gases to accumulate to a level of concern.

When piping with a diameter of four inches (i.e., 4-inch Nominal Pipe Size [NPS]) or less fails in a flammable gas explosion, the failure mechanism of the piping is such that it can split, tear, or break, but the piping does not turn into multiple energetic projectiles (also referred to as shrapnel or missiles) that can injure personnel or damage equipment in the vicinity (24590-WTP-RPP-ENG-11-010, Rev. 0, Non-Fragmentation of Ancillary Equipment Caused by Hydrogen Detonations). Therefore, for an explosion that occurs in a pipe with a diameter of four inches (i.e., 4-inch NPS) or less, the consequences are low for all receptors unless the explosion releases enough MAR to cause exposure to a significant amount of radioactive or toxic material.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the control strategy described in the tank farm DSA is expected to be sufficient to protect workers in events associated with these activities. The control strategy for these events is described in Subsection 3.3.2.4.1 the tank farm DSA (RPP-13033) and in Tables A 07 and B 07of the tank farm data base report (RPP-15188). This strategy includes crediting (as an SAC) the

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Flammable Gas Controls. In addition, the waste transfer primary piping systems configuration is an SS SSC that is credited with preventing a DST annulus flammable gas event that could be caused by a misroute of waste into the annulus.

3.3.6 Direct Radiation Control Strategy

Preliminary evaluations indicate that no direct radiation accident could result in consequences that would exceed public or onsite worker radiological evaluation criteria. Preliminary evaluations also indicate consequences associated with some unmitigated direct radiationscenarios could have significant radiological consequences to FWs. As indicated in Table 2, forTSCR operations and activities associated with the spent IXC storage pad, the control strategy for these events includes crediting (as SS SSCs) the following controls:

IXCs are credited with being SS for providing sufficient shielding to reduce potential FWradiation exposures to acceptable levels. As part of the PrHA and control development processes, the acceptable levels will be defined. From this value, the potential CST loading, and the IXC geometry, performance criteria will be developed.

Double valve isolation SSCs are SS, credited with providing protection against misrouting one of the liquid process streams (tank farm supernate, filtered tank farm supernate, or the LAW supernate product) into one of the utility systems. In a similar event, a liquid process stream misroute could also fail the utility confinement boundary resulting in a loss-of-confinement event. Subsection 3.3.3 includes a summary of the loss-of-confinement accident.

In addition, while not credited in these events, the TSCR enclosure and access controls provide protection from direct exposure events during processing of tank farm supernate.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the control strategy described in the tank farm DSA is expected to be sufficient to protect workers in events associated with these activities. The control strategy for these events is described in Subsections 3.3.2.4.3 of the tank farm DSA (RPP-13033) and in in Tables A 06, A 16, B 06, and B 16 of the tank farm data base report (RPP-15188). This strategy includes crediting (as an SS SSC) the waste transfer primary piping systems.

In addition, for LAWPS Sub-Project One, the direct exposure control strategy includes other features that are not credited as SACs or as SS SSCs. Several attributes of the tank farm operations radiation protection program provide FW protection from exposures associated with high radiation areas and areas that have the potential to become high radiation areas.

3.3.7 Criticality Control Strategy

No credible inadvertent criticality events are expected to be identified for any activities associated with LAWPS Sub-Project One. A criticality safety evaluation will be performed for TSCR operations and activities associated with the spent IXC storage pad. This evaluation will either be documented in a TSCR-specific report or will be included as part of the tank farm criticality safety evaluation documentation. While no credible TSCR criticality events are

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expected to be identified, a control is expected to be necessary to protect the tank farm supernate composition assumed as an initial condition for these evaluations. As indicated in Tables 2 and 4, this control will be the TSCR waste acceptance criteria SAC.

For waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm), the control strategy described in the tank farm DSA is expected to be sufficient to protect workers in events associated with these activities. The control strategy for these events is described in Subsection 5.5.3.5 and Chapter 6 of the tank farm DSA (RPP-13033) and in in Tables A 02 and B 02 of the tank farm data base report (RPP-15188). This strategy includes implementing key elements of Nuclear Criticality Safety described in Subsection 5.5.3.5 and Chapter 6 of the tank farm DSA.

4.0 RISKS TO PROJECT SAFETY DECISIONS

Risks to project safety decisions during design would include omission of key safety functions (safety functions that have a significant influence on design and cost) or misclassification of key safety functions. The highest risk is for decisions associated with TSCR operations and activities associated with the spent IXC interim storage pad. Safety functions that are historically significant to design and cost are addressed in Section 3.3. Controls for major hazards are addressed in Table 2 and are generally similar to those already in use in the tank farms and242-A Evaporator. As the design evolves, there is the risk of design changes affecting the hazards, controls and accident analyses. The PrHA will be updated during each design phase. Of particular vulnerability to stakeholder misalignments is the control strategy for protecting against flammable gas accumulations.

The risk of a major impact on the project is managed by, in general, making conservative assumptions during the early phases of design. However, key risks and opportunities for theTSCR that are important to be recognized by the approval authority are summarized in Table6.

Because key safety decisions for waste transfer activities (i.e., delivery of waste into TSCR, transfer of returns from TSCR into the AP tank farm, delivery of LAW into WTP, and receipt of returns from WTP into the AP tank farm) were made when the strategies were implemented in the tank farm DSA, risks to the project are much less for these activities. Risks associated with waste transfer activities are primarily associated with the potential for assumptions, hazards, accident scenarios, controls, or performance criteria that are different from the waste transfersevaluated for in the tank farm DSA.

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Table 6. LAWPS Sub-Project One Safety-in-Design Risks and Opportunities.

Risk/Opportunity Causes Key Actions Planned Mitigation Strategy

Risk – DSAaddendumimplementation identifies the need for significant DSAaddendum rework or DOE review comments on the DSA addendumimpact implementation (e.g., comments on maintenance and testing procedures).

Holdup due to DSA addendumrework might be identified during implementation (e.g., operations or maintenance procedure development, testing).

1. Develop maintenance and testing requirements as part of SS SSC control development for 90% design and include in PDSA.

2. Operations, maintenance, and testing organization careful review of DSA prior to submittal.

3. Inform procedures and testing group of DSA comments that might impact maintenance and testing procedures.

Managed through risk and opportunities register.

Holdup or rework in DSA addendum implementation might be caused by DSA addendum rework to address DOE review comments.

DSA addendum due date is advanced.

Chemical reagent SS controls are imposed earlier prior to runs.

Chemical hazards will be present during acceptance testing

Toxicological hazard similarity of waste simulant exists.

DSA addendum is required to perform operational acceptance testing.

Risk – PDSA approval delayed

Significant rework to address DOE comments.

1. Base the PDSA (include accident analysis, control strategy, and SSC design approach) on the DOE approved SDS approach.

2. Discuss changes to safety approach as they occur with the Safety in Design Integration Team, which includes ORP attendance invitation.

3. Brief the ORP Integrated Project Team (IPT) of significant changes in safety approach as they occur.

4. Invite ORP to perform over-the-shoulder review of draft PDSA.

Managed through risk and opportunities register.

Significant change to transfer line control strategy required to address hazard, accident scenario or control develop that differ from the transfer line safety strategy in the tank farm DSA.

Control strategy does not meet DOE expectations.

Accident analysis methodology does not meet DOE expectation

Safety SSC design does not meet DOE expectations due to lack of applicable DOE O 420.1 codes and standards.

PDSA = Preliminary Documented Safety Analysis

TSCR = Tank-Side Cesium Removal.

WTP = Waste Treatment Plant.

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5.0 SAFETY ANALYSIS APPROACH AND PLAN

DOE-STD-1189-2008 states, “Tailoring of the safety design basis development steps and documents for a project is also permitted based on the level of risk posed by the facility chemical and radiological hazards, the complexity of the processing operations, and the scope of the hazards analysis required for the project.” With respect to the level of risk posed by the activities associated with LAWPS Sub-Project One, even in the unmitigated accident scenarios, risks are limited essentially to FW consequences (with the exception of the unmitigated design-basis seismic event and high-energy impact events, either of which could have significant onsite worker consequences but no significant public consequences).

With respect to the complexity of operations and the scope of the associated hazards analysis, the processing operations associated with LAWPS Sub-Project One are limited to transferring of the untreated and treated waste streams between the tank farm and TSCR unit, filtration to remove particulates, ion exchange to remove cesium, activities that support these operations (e.g., storage of spent ion exchange material), and transfer of transfers between the 241-AP tank farm and WTP. The simplicity of these operations combined with the simplicity of the TSCR and spent IXC interim storage pad designs will limit the scope of the hazards analysis needed to support development of the LAWPS Sub-Project One safety basis.

Because of this simplicity and because not tailoring some of the documentation specified by DOE-STD-1189-2008 would duplicate information being presented in other project documents, for LAWPS Sub-Project One, the safety basis development and documentation has been tailored. Table 7 is a summary of the tailored approach. RPP-PLAN-62160, TD101, Tank Side Cesium Removal (TSCR) Demonstration Project Execution Plan, is a description of the approach for the TSCR Demonstration scope. This project execution plan includes a copy of the TSCR project tailoring checklist and a summary of the safety basis development and documentation tailoring.

5.1 TAILORED APPROACH FOR DEVELOPING THE LAWPS SUB-PROJECT ONE SAFETY BASIS

As shown in Table 7, for LAWPS Sub-Project One, safety basis development has been tailored to align with the project design reviews specified in the TSCR Demonstration PEP (RPP-PLAN-62160), TSCR system specification (RPP-SPEC-62088), and vendor specification (RPP-SPEC-61910). Initial safety basis development activities were performed to support implementation of safety into the TSCR system and spent IXC interim storage pad. This SDS documents safety basis development activities typically performed as part of pre-conceptual planning and design(CD-0/1). This SDS meets the intent of the following DOE-STD-1189-2008 pre-conceptual and conceptual design items:

SDS initial issue to document safety hazards identification, pre-conceptual hazards analysis, the TSCR unit hazard categorization, and safety-in-design tailoring strategy.

DOE expectations for safety-in-design. The LAWPS Sub-Project One safety basis is being implemented as an addendum to the Hanford tank farm DSA and revision to the tank farm TSR document. DOE expectations for safety in the TSCR design is aligned with DOE expectations for safety in the operations of the tank farm. Rather than issue a

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separate document, by approval of this SDS, DOE is concurring with the safety-in-design approach herein.

Revised SDS typically issued as part of the conceptual design package. In addition to results from the preliminary hazard analysis, this SDS includes an indication of the safetyfunctions and functional classifications of the key safety SSCs. Because a vendor design had not been identified at this phase of the project, the preliminary hazard analysis was modified to capture evaluations of the design at the detail of the specifications. Rather than perform structured hazards analysis at this point in the design, results for the hazardsevaluation have been developed by members of the TSCR Contractor Integrated Project Team (CIPT).

The following information typically documented in a Conceptual Safety Design Report: preliminary hazard categorization, preliminary representative accident identification, the need for SS hazards controls, the rationale for safety-class hazards controls being unnecessary, preliminary seismic design criteria, and positions to be taken to ensure compliance with criteria of DOE O 420.1C.

Table 7 is a summary of the critical decisions and milestones associated with development of safety basis documentation for LAWPS Sub-Project One. As indicated in DOE-STD-1189, the final step of CD-3 approval is DOE’s authorization of procurement, construction and final implementation. For LAWPS Sub-Project One, three sets of procurement and construction activities will be authorized by approval of three distinct CD-3 packages. These are approvals of a:

Long-lead equipment procurement package (CD-3A) for the TSCR System,

Long-lead equipment procurement and site preparation package (CD-3B) for major DFLAW Feed Delivery Upgrade components (waste transfer lines, hoses, pumps, etc.),

Combined CD-2 and CD-3 package (CD-2/3) authorizing the rest of the Subproject One procurement and construction activities, and authorizing final implementation activities.

As shown in Table 7, the TSCR System long-lead equipment procurement package (CD-3A) has been completed. This allowed for a contract to be released for the design and fabrication of the TSCR unit. In parallel with the activities needed to receive CD-3A approval, a draft of this SDS was prepared and reviewed (by WRPS Subject Matter Experts, ORP personnel, and by DOE Field Operations Oversight/Chief of Nuclear Safety personnel).

A CD-3B package will be developed and approved to allow for limited site preparation and procurement of key long-lead items associated with DFLAW Feed Delivery Upgrade components. To support the development of this package, this Revision 0 of this SDS will be issued to document the proposed safety strategy. After issuing this SDS and upon completion of the 30 % design package for the TSCR unit, a PrHA and control selection will be performed. Upon completion of control selection, a memorandum (e.g., an e-mail) will be sent to the WRPS Nuclear Safety Manager documenting the results of the control selection. The control selection memorandum and this SDS will support the CD-3B package.

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Most of the design activities in support of the 30 % design review will be performed by suppliers prior to awarding of the contract. Therefore, most of the safety basis activities typically associated with a 30 % design either were performed prior to this phase (as indicated in the first paragraph of this subsection) or will be captured as part of the tailored safety basis development in support of the 60 % design review.

To support the 60 % design activities, the safety basis development activities have been tailored to meet the intent of the activities specified by DOE-STD-1189-2008 in support of preliminary design. Some aspects of the LAWPS Sub-Project One safety basis have already been developed and implemented for other Hanford tank farm facilities. For this reason and because of the other aspects the LAWPS Sub-Project One safety basis development tailoring approach discussed previously, a Preliminary Safety Design Report (PSDR) will not be developed for Sub-Project One of the LAWPS Project. The following safety-in-design aspects of a typical PSDR will be captured in other safety basis documents as indicated in the following:

Site information has been captured in Chapter 1 of the tank farm DSA (RPP-13033).

Facility and process descriptions will be summarized in a revision to this SDS to be issued after the first PrHA and control selection for Sub-Project One of the LAWPS Project. A more detailed description will be provided in the TSCR PDSA.

Results from the PrHA (including the process hazards evaluation) will be provided in aPrHA report. The resulting SS SSCs, their functional classifications, key representative accidents, and NPH design criteria will be summarized in a revision to this SDS to be issued after the first PrHA and control selection. Also included in this revision will be safety functions, functional requirements, and performance criteria for SACs and SS SSCs.

Results from a preliminary criticality evaluation will be documented in a criticality safety evaluation report (CSER) or other documentation according to tank farm criticality control programs and procedures.

If additional elements will need to be added to the tank farm safety management programs, these will be identified in the revision to this SDS that is to be issued after the first TSCR PrHA.

The safety basis development process and documentation planned to support CD-2/3 are aligned with the DOE-STD-1189-2008 final design phase. These safety activities and documentationhave been listed in Table 7. A PDSA will be submitted as part of the CD-2/3 package. Also, included in this review package will be documentation of the control development process (i.e., the Functions and Requirements Evaluation Document [FRED] and Safety Requirements Evaluation Document [SRED]) and if needed, a revision to this SDS.

The safety basis development process and documentation planned to support transition to operations are aligned with the construction, transition, and closeout activities and documentdescribed in DOE-STD-1189-2008. These activities will include a review of the hazards analyses that will have been completed as part of the PDSA development. The purpose of this

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final review of the hazards analysis results is “to ensure that they remain accurate and that changes are made as necessary” (DOE-STD-1189-2008). During this phase, the PDSA will be converted into an amendment to the Hanford tank farm DSA (RPP-13033), and the tank farm TSR document (HNF-SD-WM-TSR-006) will be revised.

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Table 7. Planned Safety Analysis and Deliverables for LAWPS Sub-Project One.

Critical Decision or Milestone

Planned Safety Analysis (as needed) Deliverables

CD-3A(Approval to Award TSCR Unit Subcontract)‒ complete

Develop scoping hazard analysis Perform a scoping TSCR unit hazard

categorization

SDS (draft)

*CD-3B(Approval to Initiate Limited Site Preparation and Procurement of Key Long-Lead Items for Tank Farm Upgrades)

Perform hazard analysis Identify controls for accidents with onsite

or FW consequences (ACs, SACs, active engineered controls, and DFs)

Update functional classification of SSCs*

SDS (initial issue) *Control Selection Memorandum

60% Design Completion

Determine the preliminary TSCR unit hazard categorization

Select and analyze representative accidents for TSCR, including addressing identified risks and opportunities

Evaluate beyond design basis events

PrHA Document (initial issue) Updated SDS (as needed) Updated Tank Farm FHA (as needed) CSER (draft revision to tank farms

documentation, as needed)

CD-2/3(Approval to Initiate Construction)

Complete initial representative accidentunmitigated consequence calculations

Develop controls for accidents with onsite or FW consequences

Finalize SSCs functional classifications and demonstrate adequacy of the controls

Provide final TSCR unit hazard categorization

Update hazard analysis Update control development

Representative Accident Unmitigated Consequence Document (initial issue)

FRED (initial issue) SRED (initial issue, as needed) Updated SDS (as needed) Updated Tank Farm FHA (as needed) Updated PrHA Document (as needed) PDSA (initial issue)

**CD-4(Completion of Construction, Transition, andCloseout)

Verify hazard analysis (construction complete)

Verify control development (e.g., functional requirements, performance criteria)

Develop TSR revisions

Updated FRED (as needed) Updated SRED (as needed) Updated Tank Farm FHA (as needed) Updated CSER (if needed) Tank Farm DSA Addendum Tank Farm TSR Document Revision

*As part of the CD-3B package, a memorandum (e-mail) will be issued identifying the credited administrative controls and safety significant SSCs.

**CD-4 might occur at a different time for TSCR activities and WTP transfer line activities. Applicabledeliverables must be approved and implemented before a the affected systems are transitioned into operation.

AC = administrative control.

CD = Critical Decision.

CSER = Criticality Safety Evaluation Report.

DSA = Documented Safety Analysis.

FHA = Fire Hazards Analysis.

PDSA = Preliminary Documented Safety Analysis.

PrHA = Process Hazards Analysis.


SSC = structures, systems, and component.

SDS = safety design strategy.

TSCR = tank-side cesium removal.

TSR = technical safety requirement.

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5.2 CHANGE CONTROL

The objective of change control is to maintain consistency among design requirements, the physical configuration, and the related TSCR unit documentation, even as changes are made. The TSCR project will implement a safety basis change control process for safety documentation consistent with Section 6.4 of DOE-STD-1189-2008.

As design matures, changes to the design, hazards, and resulting safety controls will be discussedin regularly scheduled Safety Design Integration Team (SDIT) meetings and will be communicated to the CIPT via communication from the SDIT. Changes will be captured in the PDSA at the appropriate time in the design maturation process. The PDSA will detail any changes to safety-in-design decisions or significant changes to commitments described in theSDS. Upon approval of the PDSA, a configuration baseline will be established for safety-in-design elements. If these elements are changed, a change to the PDSA will be required through a formal PDSA change control process that will be implemented with submittal of the PDSA.

Upon submittal of the LAWPS Sub-Project One addendum to the tank farm DSA and revision to the tank farm TSRs, which together will supersede the SDS, the TOC unreviewed safety question process will be invoked for the LAWPS Sub-Project One modifications.

5.3 SAFETY ANALYSIS SOFTWARE

Safety analysis tools that may be used to perform safety analysis for LAWPS Sub-Project Oneincludes software for atmospheric dispersion, direct radiation hazards, and in support of criticality evaluations.

New atmospheric dispersion factors will be developed using five years of representative, recent meteorological data. These atmospheric dispersion factors will be determined using DOE-approved toolbox code (https://www.energy.gov/ehss/safety-software-quality-assurance-central-registry) Generation II Model for Environmental Dose Calculations (GENII), Version 2.10.1.

Direct radiation dose rates will be calculated with Monte Carlo N-Particle Version 5 (MCNP5), Release 1.51 or Monte Carlo N-Particle Version 6 (MCNP6), Release 1.0, with input from SCALE 6.1.2.

If modelling is required to evaluate criticality scenarios, the criticality safety evaluation for TSCR will use MCNP5 or MCNP6. The evaluation will use the version of the software that is approved for use by TOC at the time of the evaluation.

6.0 SAFETY DESIGN INTEGRATION TEAM – INTERFACES AND INTEGRATION

The LAWPS Sub-Project One CIPT is the contractor team specifically charged with executing the project and supporting the Federal Project Director and the DOE Integrated Project Team(IPT). The LAWPS Sub-Project One CIPT members represent all competencies required for the project as described in RPP-PLAN-62160, TD101, Tank Side Cesium Removal Demonstration Project Execution Plan.

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The LAWPS Sub-Project One SDIT will be a component of the LAWPS Sub-Project One CIPT. The LAWPS Sub-Project One SDIT will be responsible for implementing safety into the designof the LAWPS Sub-Project One systems.

The core SDIT will represent the primary functional areas relied on to identify and control hazards. This core team will be supplemented by the assistance of specialists and subject matter experts in areas including radiation protection; industrial safety and health; criticality safety;environmental protection; process chemistry; testing; the DFLAW program (One System); and fire protection, as required.

The core SDIT consists of representatives from each of the following:

Design Authority, Nuclear Safety, Operations, and Design Agent.

The TSCR unit will be designed and fabricated by a contractor with established quality assurance, emergency preparedness, and security programs. The TSCR unit will be fabricated at the contractor’s off-site facilities. These aspects of the project are not expected to have a significant impact on safety and design integration for the TSCR project.

7.0 REFERENCES

ANSI/ISA-84.00.01-2004, 2004, Functional Safety: Safety Instrumented Systems for the Process Industry Sector, American National Standards Institute, Research Triangle Park, North Carolina.

DOE O 413.3A, Change 1, 2012, Program and Project Management for the Acquisition of Capital Assets, U.S. Department of Energy, Washington, D.C.

DOE O 420.1C, Change 1, 2015, Facility Safety, U.S. Department of Energy, Washington D.C.

DOE G 420.1-1A, 2012, Nonreactor Nuclear Safety Design Guide for use with DOE O 420.1C Facility Safety, U.S. Department of Energy, Washington D.C.

DOE-STD-1020-2012, DOE Standard ‒ Natural Phenomena Hazards Analysis and Design Criteria for DOE Facilities, U.S. Department of Energy, Washington, D.C.

DOE-STD-1066-2012, DOE Standard ‒ Fire Protection, U.S. Department of Energy, Washington, D.C.

DOE-STD-1189-2008, DOE Standard ‒ Integration of Safety into the Design Process, U.S. Department of Energy, Washington, D.C.

DOE-STD-1195-2011, DOE Standard ‒ Design of Safety Significant Safety Instrumented Systems Used at DOE Nonreactor Nuclear Facilities, U.S. Department of Energy, Washington, D.C.

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DOE-STD-3007-2007, DOE Standard ‒ Guidelines for Preparing Criticality Safety Evaluations at Department of Energy Nonreactor Nuclear Facilities, U.S. Department of Energy, Washington D.C.

DOE-STD-3009-94, Change Notice no, 3, DOE Standard ‒ Preparation of Nonreactor Nuclear Facility Documented Safety Analysis, U.S. Department of Energy, Washington D.C.

Downing, K. A., 2018, “Washington River Protection Solutions LLC Request to Use DOE-STD-3009-94 Change Notice 3 for Tank Side Cesium Removal Project Major Modification to the Tank Farms Documented Safety Analysis,” Letter WRPS-1800729 to W. E. Hader, ORP, February 28, 2018, Washington River Protection Solutions, LLC, Richland, Washington.

Hader, W. E., 2014, “Revision on Direction to Implement New Safety Classification Process for the Tank Farms and 242-A Evaporator Documented Safety Analyses and New Capital Projects,” Letter 14-NSD-0015/1401829 to L. D. Olson, Washington River Protection Solutions, LLC, May 14, 2014, U.S. Department of Energy, Office of River Protection, Richland, Washington.

Hader, W. E. and K. W. Smith, 2016, “Approval of Washington River Protection Solutions LLC Request to Continue to Use the Currently Implemented Industry Standard ANSI/ISA 84.00.01-2004 In Lieu of DOE-STD-1195 for the Low-Activity Waste Pretreatment System Project,” 15-NSD-0033 to M. A. Lindholm, February 17, 2016, Washington River Protection Solutions, LLC, Richland, Washington.

Harp, B. J., 2018, “Concurrence of the Washington River Protection Solutions LLC Request to Use DOE-STD-2009-94, Change Notice 3 for Tank Side Cesium Removal Project Major Modification to the Tank Farms Documented Safety Analysis,” Letter 18-TPD-0006 to M. A. Lindholm, April 6, 2018, Washington River Protection Solutions, LLC, Richland, Washington.

HNF-SD-WM-TSR-006, Rev. 8-C, Tank Farms Documented Safety Analysis, Washington River Protection Solutions, LLC, Richland, Washington.

MGT-ENG-IP-05, ORP Fire Protection Program, Revision 0, U.S. Department of Energy, Office of River Protection, Richland, Washington.

NFPA 13, Standard for the Installation of Sprinkler Systems, 2013 Edition, National Fire Protection Association, Quincy, Massachusetts.

RPP-13033, Rev. 7-G, Tank Farms Documented Safety Analysis, Washington River Protection Solutions, LLC, Richland, Washington.

RPP-PLAN-62160, TD101, Tank Side Cesium Removal (TSCR) Demonstration Project Execution Plan, Revision C, Washington River Protection Solutions, LLC, Richland, Washington.

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RPP-CALC-62212, Unmitigated Design Basis Accident Consequence Analysis for the Low-Activity Waste Pretreatment System, Revision 0.

RPP-SPEC-61910, Specification for the Tank-Side Cesium Removal Demonstration Project [Project TD101]).

RPP-SPEC-62088, Project TD101 Tank Side Cesium Removal Technology Demonstration System Specification.

Johnson, J. and Smith, S. C., Low-Activity Waste Pretreatment System Preliminary Project Execution Plan, Revision 2.

TFC-ENG-DESIGN-C-47, Process Hazard Analysis, as amended, Washington River Protection Solutions, LLC, Richland, Washington.

WRPS-1800729, Washington River Protection Solutions LLC Request to Use DOE-STD-3009-94 Change Notice 3 for the Tank Side Cesium Removal Project Major Modification to the Tank Farms Documented Safety Analysis, Washington River Protection Solutions, LLC, Richland, Washington.

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CONFINEMENT EVALUATION

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CONTENTS

A1.0 THE TANK-SIDE CESIUM REMOVAL SYSTEM...................................................... A-1A1.1 Number, Arrangement, and Characteristics of Confinement Barriers .................. A-1A1.2 Type, Quantity, Form, and Conditions for Dispersing Radioactive Material ....... A-2

A1.2.1 Leaks and Spills ....................................................................................... A-2A1.2.2 Flammable Gas Explosions in TSCR Piping ........................................... A-3A1.2.3 Flammable Gas Hazards in the Ion-Exchange Columns.......................... A-3A1.2.4 Flammable Gas Hazards in the Filter....................................................... A-3

A1.3 TSCR Ventilation.................................................................................................. A-4A1.4 Documentation of Adequacy of the Confinement Approach................................ A-4

A2.0 REFERENCES................................................................................................................. A-4

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APPENDX A. CONFINEMENT EVALUATION

This appendix is a summary of the results from a preliminary Tank-Side Cesium Removal (TSCR) confinement evaluation. This evaluation describes how the TSCR confinement strategy meets requirements of DOE O 420.1C, Facility Safety, as described below. The approach for complying with DOE O 420.1C, Chapter 1, Section 3.b(3), Requirement (c) (given in the following paragraph) will not be fully established until after completion of the TSCR PrHA and control selection.

The requirements for confinement from DOE O 420.1C, Chapter 1, are as follows:

“3.b.(3). Hazard category 1, 2, and 3 nuclear facilities with uncontained radioactive materials (as opposed to materials determined by safety analyses to be adequately contained within qualified drums, grout, or vitrified materials) must have the means to confine the uncontained radioactive materials to minimize their potential release in facility effluents during normal operations and during and following accidents, up to and including design basis accidents (DBAs). Confinement design must include the following:

(a) For a specific nuclear facility, the number, arrangement, and characteristics of confinement barriers as determined on a case-by-case basis.

(b) The type, quantity, form, and conditions for dispersing the radioactive material in the confinement system design.

(c) An active confinement ventilation system as the preferred design approach for nuclear facilities with potential for radiological release.3 Alternate confinement approaches may be acceptable if a technical evaluation demonstrates that the alternate confinement approach results in very high assurance of the confinement of radioactive materials.

The guidance for confinement ventilation systems and evaluation of the alternatives, is provided in DOE Guide (G) 420.1-1A, Nonreactor Nuclear Safety Design Guide for Use with DOE O 420.1C, Facility Safety.

(d) Documentation of the adequacy of confinement systems consistent with the safety in design process as described in DOE-STD-1189-2008.

3 The safety classification (if any) of the ventilation system is determined by the facility documented safety analysis.”

A1.0 THE TANK-SIDE CESIUM REMOVAL SYSTEM

A1.1 NUMBER, ARRANGEMENT, AND CHARACTERISTICS OF CONFINEMENT BARRIERS

The confinement strategy for TSCR includes both primary confinement (i.e., process piping, pressure vessels, and atmospheric tanks), passive secondary confinement, and active ventilation for the TSCR enclosure, which will house the TSCR processing system. Confinement features

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selected for loss of confinement events that could exceed consequence guidelines have been classified as safety significant.

Primary confinement will be provided by TSCR process piping, pressure vessels (filter unit pressure boundary and ion-exchange column pressure boundary), and other pressurized equipment. The piping is designed to ASME®1 B 31.3, Process Piping, and the pressure vessels are designed to ASME Boiler and Pressure Vessel Code (ASME B&PV, Section VIII).

As design matures, SSCs associated with the passive secondary confinement will be defined.

Active ventilation will be provided to control the spread of contamination through filtration and differential pressure induced cascade airflows through the building.

A1.2 TYPE, QUANTITY, FORM, AND CONDITIONS FOR DISPERSING RADIOACTIVE MATERIAL

The radioactive material at risk within the TSCR primary confinement will include: (1) tank farm waste supernate (including small amounts of entrained waste solids) in the filter and ion-exchange columns; (2) ion-exchange media (CST loaded with cesium-137) in the ion-exchange columns; and (3) waste in process piping and inline components. Waste in the process piping and pressure vessels is expected to be under moderate pressure during process operations.

Dispersive scenarios within the TSCR enclosure include: (1) leaks and spills from the primary confinement, (2) spray leaks from the pressurized portion of process piping and pressurized equipment, and (3) dispersion from flammable gas explosions in the ion-exchange columns.

A1.2.1 Leaks and Spills

Preliminary calculations indicate the unmitigated consequences from a high-pressure spray leak of the TSCR supernate feed stream could not exceed onsite worker radiological (100 rem) ortoxicological (PAC-3) criteria. In addition, because the TSCR process is such that hazardous liquid streams will not reach pressures that could cause fine spray leaks, even under upset conditions, spray and leak accidents would not challenge the offsite Evaluation Guideline (25 rem) or toxicological (PAC-1) criteria. Therefore, TSCR spray leak accident events cannotexceed these onsite worker or offsite radiological or toxicological criteria.

Protection from leaks and spills will be provided by maintaining FWs at a safe distance from the primary confinement during operations and by defense-in-depth passive primary confinement. Preliminary calculations indicate the unmitigated consequences of leaks and spills would be below onsite worker radiological (100 rem) and toxicological (PAC-3) criteria, but have the potential to be a significant FW hazard, and therefore, access controls will be implemented to protect FWs from the consequences of leaks and spills.

1 ASME is a registered trademark of the American Society of Mechanical Engineers, New York, New York.

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A1.2.2 Flammable Gas Explosions in TSCR Piping

Waste generates flammable gas, primarily hydrogen, through radiolysis of water and organics, and thermolytic decomposition of organic compounds. Because of the high cesium-137 source term, radiolytic flammable gas generation rates can be relatively high at some points in the TSCR process. As discussed in Section 3.3.5, pipes do not shrapnel in a flammable gas explosion if the diameter of the pipe is four inches or less. The TSCR control strategy is to prevent flammable gas explosions; however, because the TSCR pipe diameters will be four inches or less, if an explosion were to occur, TSCR piping would not produce shrapnel.

In some scenarios, piping could contain a flammable gas; however, preliminary calculations indicate the consequences of a flammable gas explosion in the piping would not challenge public radiological EG (5 rem) or exceed the public toxicological (PAC-2), onsite radiological (100 rem) or toxicological (PAC-3) criteria. In addition, explosions do not produce missiles when they occur in pipe with diameters less than four inches. Therefore, the presence of explosive mixtures in TSCR piping is not a missile hazard. To protect FWs from exposure to a process stream that could be released in an explosion, when process streams are in the piping, FWs will be maintained at a safe distance by access controls.

A1.2.3 Flammable Gas Hazards in the Ion-Exchange Columns

Flammable gases generated within the IXCs will remain in solution under process pressures and will be swept through the IXCs in the process flow. However, after a loss of process flow, these flammable gases could accumulate in the ion-exchange column and be ignited if an ignition source is present. Calculations will be performed to determine the time necessary for sufficient flammable gas to accumulate to potentially breach the confinement boundary in an unmitigated scenario. Without controls, assuming that the entire IXC internal volume contains flammable gas that is ignited and the primary confinement barrier is breached, the energy of combustion is insufficient to release enough waste material (including cesium from the CST media) to exceed offsite or onsite criteria. However, it is conservatively assumed that this unmitigated event has sufficient energy to pose a significant FW hazard because of blast overpressure and exposure to potentially highly radioactive CST that could be released in the explosion. The following controls have been selected to protect FWs from a flammable gas hazard in the ion-exchange columns:

IXC process vent

Sweep system

TSCR process enclosure access controls

A1.2.4 Flammable Gas Hazards in the Filter

Similar to the ion exchange column, flammable gases could accumulate in the filter unit. Preliminary calculations indicate the unmitigated consequences of explosion events in these SSCs would be lower than the potential of an unmitigated IXC explosion. Although lower than the potential consequences associated with an IXC explosion, unmitigated flammable gas explosions in the filter unit would have the potential to result in significant FW consequences.

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A-4

The control strategy to protect FWs in the filter unit explosion events is similar to the IXC explosion strategy. The following controls have been selected to protect FWs from a flammable gas hazard in the filter unit:

Filter unit process vent

Sweep system

TSCR process enclosure access controls

Process filter housing (does not produce missiles in a flammable gas explosion)

A1.3 TSCR VENTILATION

The TSCR enclosure and process system ventilation systems will provide active ventilation. Upon completion of the TSCR PrHA and control selection, the approach for complying with DOE O 420.1C, Chapter 1, Section 3.b(3), Requirement (c) will be identified, and will be summarized in a subsequent revision to this SDS.

A1.4 DOCUMENTATION OF ADEQUACY OF THE CONFINEMENT APPROACH

The evaluation of the adequacy of the confinement barriers will be documented in the appropriate sections of the TSCR addendum to the tank farm Documented Safety Analysis (e.g., Section 4.4., “Safety-Significant Structure, System, or Component,” for the SS SSCs; and Section 3.3.2.4 “Defense-in-Depth,” for non-SS barriers).

A2.0 REFERENCES

ASME B31.3-2016, Process Piping, American Society of Mechanical Engineers, New York, New York.

ASME BPVC, 2013, ASME Boiler and Pressure Vessel Code, Section VIII, “Rules for Construction of Pressure Vessels,” American Society of Mechanical Engineers, New York, New York.

DOE O 420.1C, Change 1, 2015, Facility Safety, U.S. Department of Energy, Washington D.C.

DOE G 420.1-1A, 2012, Nonreactor Nuclear Safety Design Guide for use with DOE O 420.1C Facility Safety, U.S. Department of Energy, Washington D.C.

DOE-STD-1189-2008, DOE Standard ‒ Integration of Safety into the Design Process, U.S. Department of Energy, Washington, D.C.

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