The Safety Case and the Risk-Informed

Performance-Based Approach for Management of

US Commercial Low-Level Waste (Paper #190)

Rateb (Boby) Abu-Eid, David Esh,

and Christopher Grossman

Division of Decommissioning, Uranium Recovery, and Waste

Management Programs

Office of Nuclear Material Safety and Safeguards

United States Nuclear Regulatory Commission

IAEA International Conference on Safety of Radioactive Waste Management

November 21-25, 2016 Vienna, Austria

Disclaimer Note

• Certain materials in this presentation involves

ongoing amendments of 10 CFR Part 61 and

implementation final draft technical guidance

document (NUREG-2175).

• We note that the final provisions of 10 CFR Part 61

amendment and the final draft NUREG-2175 are

currently subject to Commission review and

approval.

3

Stak

eh

old

er a

nd

Re

gula

tory

Invo

lve

me

nt

Ap

plicatio

n o

f Man

agem

en

t System

C. System Description

D. Safety Assessment

G. Limits, Controls and Conditions

H. Integration of Safety Arguments E. It

era

tio

n a

nd

De

sign

Op

tim

izat

ion

F. M

anage

me

nt o

f Un

certain

ty A. Safety Case Context B. Safety Strategy

IAEA Safety Case Components

(IAEA SSG-23)

US Presidential/Congressional

Commission on Risk Assessment & Risk

Management, 1997

US GAO Risk Management

Framework, 2005

A, B A,B

C, E D, H

D, F,G

C,E

E, F

G, H

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NRC Risk-Informed Performance-Based

Regulations

• The NRC developed a Probabilistic Risk Assessment (PRA) Implementation

Plan (1994). This plan was superseded in 2000 by the Risk-Informed

Regulation Implementation Plan (RIRIP).

• Many of the NRC regulations were based on deterministic and prescriptive

requirements.

• US Low-Level Waste (LLW) regulations under 10 CFR Part 61, developed in

1980’s, were based on risk (dose) to members of the public, risk to

inadvertent intruder, and disposal site performance.

• In April 2007, the NRC replaced the RIRIP with the Risk-Informed,

Performance-Based Plan (RPP). Each of these plans has guided the NRC in

developing risk-informed performance-based regulations and

implementation guides.

• Currently, the NRC is amending its regulations that govern low-level

radioactive waste disposal facilities to require new and revised site-specific

technical analyses (Federal Register /Vol. 80, No. 58 /Thursday, March 26,

2015).

Technical Analysis Techniques and

Deliberation (NUREG-2150)

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Aspects of Safety Case in NUREG-2175

• Strategy for Achieving Safe Disposal of Radioactive Waste;

• Description of the Disposal Site and Facility;

• Description of the Technical Analyses;

• Demonstrating Performance Objectives;

• Strategy for Institutional Control of the Disposal Site;

• Description of Financial Qualifications of the Licensee;

• Description of Other Information; and

• Safety Arguments/Functions.

Revised Part 61 Overview

• Safety case and defense-in-depth protections;

• Site-specific technical analyses (performance assessment,

intruder assessment, site-stability);

• Time of compliance considering waste characteristics;

• Site-specific intruder receptors;

• Waste acceptance criteria may be developed based on the

results of the technical analyses;

• Updated dose methodologies;

• Consideration of uncertainty;

• Model support; and

• Site characteristics consider waste characteristics and are risk-

informed, performance-based.

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Example: Waste Acceptance Criteria

• Allowable Limits

on Radioactivity

• Waste form

Characteristics

and Container

Specifications

• Restrictions and

Prohibitions

9

10

CFR

Par

t 6

1 A

ccep

tan

ce

Cri

teri

a

Allowable Radioactivity Limits

Acceptable Waste Form Characteristics and

Container Specifications

Restrictions and Prohibitions

Example: Defense-in-Depth

• The use of multiple, independent, and, where possible,

redundant layers of defense so that no single layer, no

matter how robust, is exclusively relied upon.

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Note: Lifecycle timeframes not to scale

• Identify defense-in-depth protections commensurate with risks.

• Describe capabilities of defense-in-depth protections.

• Provide a technical basis for capabilities of defense-in-depth protections.

Summary/Conclusion Safety Case & 10 CFR Part 61

• Safety Case is an integrated approach to risk assessment and risk management.

• NRC staff explicitly added “the safety case” concept in the ongoing amendment

of 10 CFR Part 61, at the direction of Commission.

• Plain language description the safety arguments and evidence to demonstrate

the overall safety of a land disposal facility were developed.

• It describes all safety relevant aspects of the disposal site, the design of the

facility, and the managerial control measures and regulatory controls to inform

the decision whether to grant a license.

• It includes the same type of information that the original 10 CFR Part 61

required to be submitted as part of a license application (i.e., 10 CFR 61.10 – 10

CFR 61.16).

• The safety case will be updated over time as a new information is gained during

the various phases of the facility’s development, inspection, and operation.

• 10 CFR Part 61 SC is quite consistent with IAEA SSG-23 with more detailed

technical analysis.

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BACK-UP SLIDES

Timeframes

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Waste specific

Who will perform these Technical Analyses? Commercial LLRW Sites in U.S.

US Ecology,

Hanford, WA

EnergySolutions,

Clive, Utah

Energy Solutions,

Barnwell SC

Waste Control

Specialists,

Andrews, TX

Facility Waste Compact

Restrictions

Richland, WA A, B, C 11 Western states

in 2 LLW

Compacts only

Clive, UT A only None, all US

generators OK

(Compacts must

approve)

Barnwell, SC

A, B, C SC, NJ, CT only

(Atlantic

Compact)

Andrews Cty,

Texas

A, B, C Texas and VT

(Texas Compact),

Others with

Compact

approval

Richland, Washington

Operating facility

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Normal Activities

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Dwelling Construction

Agriculture

Drilling for Water

Site-specific Scenarios -

Guidance

• Constrain exposure pathways for normal or

reasonably foreseeable activities based on:

– Physical information

• Waste characteristics and disposal practices

• Disposal site characteristics

– Cultural information (e.g. land use)

• Provide comparison of results from site-specific

scenarios to generic scenarios.

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Site Stability - Guidance

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Waste Acceptance Requirements

• Licensees must review

their waste acceptance

program at least annually

• Ensures that the program

continues to be adequate

and is being implemented

in a way that continues to

protect public health and

safety

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NUREG-2175

• NUREG-2175 (Guidance for Conducting Technical Analyses for 10 CFR Part 61) provides:

─ Flowcharts, NRC staff recommendations, and examples for how licensees can develop high-quality technical analyses

─ Guidelines for what licensees or applicants should include and what regulators should review for each type of analysis

─ Suggested references, screening tools, and case studies

• DRAFT final version made publically available in ADAMS and on the public website

http://www.nrc.gov/about-nrc/regulatory/rulemaking/potential-rulemaking/uw-streams.html

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