ML23251A059

Session 3 - Development of Risk-Informed and Performance-Based (RIPB) Standards

ML23251A059
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Issue date:	09/13/2023
From:	Robert Roche-Rivera NRC/RES/DE
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Development of Risk-Informed and Performance-Based (RIPB) Standards Opening Remarks by Mike Franovich, Division Director, NRR/DRA

Session Chair: Matthew Humberstone, Senior Reliability and Risk Analyst,R ES/DRA/PRB

Panelists/Speakers:

Prasad Kadambi (ANS)

David Grabaskas (ASME/ANS JCNRM)

Andrew Whittaker (ASCE)

Rebecca Steinman (IEEE)

Tom Basso (NEI)

Eric Thornsbury (EPRI)

Presented to:

2023 NRC Standards Forum September 13, 2023 Overview of ANS Activities to Support RIPB Standards

N. Prasad Kadambi Chair, Risk-informed, Performance -Based Principles and Policy Committee (RP3C)

The ANS Standards Board Supports RIPB Standards To Modernize Nuclear VCS*

• Creation and operation of RP3C

• Current activities of RP3C

• ANS Standards Board (SB) has directed committees (CCs) to incorporate RIPB principles w hereANS consensus appropri ate.

• All eight CCs provide reports at every SB meeting.

- The SB recognizes the varied application and applicability of suc hprinciples to each portfolio of standards.

- Relative to advanced reactors, the Joint Committee on RiskManagement (JCNRM) plays a central role in supporting modernizati on relative to RIPB standards development

• Voluntary consensus standard as defined in OMB Circular A -119 [1]. NOTE: Numbers in brackets refer to corresponding reference numbers on slide 11.

ANS Has Been a Leader in Promoting RIPB VCS

• Recent experience with conventional VCS shows that products that have detai led shall statements give rise to system requirements that are unnecessary or too conservative.

- Frequently the motivation is driven by convenience for verification of compliance to requirements established by regulatory authorities.

• Conventional VCS often do not support economic deployment of advanced reactors m andated by the Nuclear Energy Innovation and Modernization Act (NEIMA) and supported by industry investments.

- RIPB VCS provide a more logical fit with NEIMA than conventional ones.

- ANS is in a good position to advocate for RIPB VCS by articulating specific aspects of the value proposition to move away from prescription.

- ANS is actively tackling the challenges of creating guidance for RIPB VCS.

Current Activities Toward RIPB VCS

• ANS has recognized the need to create an infrastructure to support RIPB VCS.

- Part of this is to focus on structured performance objectives such that varied levels of detail can be accommodated rigorously.

• The most visible of these activities are related to creating one or more internally consistent and coherent suites of standards that could foster further development of RIPB VCS within and outside of ANS.

• An existing example is the suite of seismic standards ANS-2.26 [2]*, 2.27 [3],

2.29 [4], and ASCE 43- 05 [5].

• Currently, ANS efforts are focused on the series ANS-30.1 [6], 30.2 [7], and 30.3 [8].

• ANS views these standards within a structure where success in issuing ANS -30.1 as a Guidance Standard, developing ANS-30.2, and obtaining regulatory endorsement of ANS -

30.3 would be major accomplishments toward RIPB VCS.

• Titles of standards are provided on slide 11.

What ANS-2.26 Does

Figure from Appendix A:

AN S-2.26:

Assign a Seismic Design Category (SDC):

Given the potential consequences of failure, assign a performance criterion:

specifically, a failure probability criterion.

The other standards then tell you how to go about engineering satisfaction of this criterion.

ANS Standards Committee Hierarchy For Advanced Reactors

AN S-30.1*

Risk and Performance Objectives (Linn)

AN S-30.2 Categorization of Structures, Systems and Components (Diaconeasa)

AN S-20.2 AN S-53.1 AN S-54.1 AN S-30.3 Liquid Molten Salt Modular Helium Cooled Liquid Sodium Cooled Advanced Light-Water Reactor Reactor Reactor Reactor (Holcomb) (August) (Flanagan) (Welter)

Advanced Reactor Large Light Water Rx

ANS and other SDO standards as needed:

- Cross cutting topics

• ANS-30.1 is now being prepared as an ANS guidance standard, - Reactor technology specific issues not as an ANSI consensus standard NRC activities support RIPB, but more can be done.

• Commission approval of SECYsignificance for RIPB standards as an example of 0096 [9] on Functional Containment has majorperformance-based principles.

- This clears the way for standards development organizations (SDOs) to consider all generaldesign criteria from a performance-based perspective.

• Similarlytechnology-inclusive for addressing certain major safety issues., issuance of RG 1.233 [10] has significance because it is meant to be

- Logicallyacceptable way to implement relevant regulations., it means that light water reactors should also be able to use its provisions as one

• NRC should recognize that industry and SDOs alike look for regulatory cues that mayencourage or discourage RIPB VCS.

• NRC can do more to clarify how the provisions of NEIMA relative to a technology -inclusive regulatory framework will use appropriate VCS for conforming with OMB Circular A-119 [1].

- Federal policy clearly favors performance-based requirements instead of prescriptive ones.

ADDITIONAL INFORMATION The ANS Standards Committee

Standards Board (Top-level committee)

Risk-informed, Performance-based Principles and Policy Task Groups Committee (RP3C)

Large Research Nonreactor Safety & Joint Nuclear Fuel, Light and Nuclear Radiological Committee Criticality Environmental Waste, and Water Advanced Facilities Analyses on Nuclear Safety and Siting Decommissioning Reactors Reactors Consensus Consensus Risk Management Consensus Consensus Consensus Consensus Consensus Committee Committee (JCNRM*) Committee Committee Committee Committee Committee (NRNFCC) (SRACC) Consensus (NCSCC) (ESCC) (FWDCC)

(LLWRCC) (RARCC) Committee

Subcommittees

Working Groups

• The JCNRM is a joint ANS and ASME committee.

Risk-informed, Performance-based Principles and Policy Committee (RP3C)

The ANS Standards Board established the RP3C to support modernizing of ANS standards. Activities for training and knowledge sharing of RIPB principles and practices are part of the scope. The RP3C is responsible for the identification and oversight of the development and implementation of RIPB approaches in ANS standards. The RP3C Community of Practice (CoP) is one of the more successful ongoing training activities. The CoP is held on the last Friday of a month and is open to all professionals interested in RIPB principles and practices. Nearly 40 CoP recordings since February 2020 are available at https://www.ans.org/standards/rp3c/cop/. Contact standards@ans.org for questions or to get on the list to receive announcements of upcoming presentations.

Titles of Cited Documents and Standards

[1] OMB Circular A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and i n Conformity Assessment Activities

[2] ANSI/ANS-2.26-2004 (R2021), Components for Seismic Design Categorization of Nuclear Facility Structures, Systems, and Components for Seismic Design

[3] ANSI/ANS-2.27-2020, Criteria for Investigations of Nuclear Facility Sites for Seismic Hazard Assessments

[4] ANSI/ANS-2.29-2020, Probabilistic Seismic Hazard Analysis

[5] ASCE/SEI 43-05, Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities

[6] ANS-GS-30.1-202X, Integrating Risk and Performance Objectives into New Reactor Nuclear Safety Designs

[7] ANS-30.2-202X, Classification and Categorization of Structures, Systems, and Components for New Nuclear Power Plants

[8] ANSI/ANS-30.3-2022, Light Water Reactor Risk-Informed, Performance-Based Design

[9] SECY-18-0096, Functional Containment Performance Criteria For Non-Light-Water-Reactors

[10] RG 1.233, Guidance for a Technology -Inclusive, Risk-Informed, and Performance-Based Methodology to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light Water Reactors ASME/ANS NON-LW R P R A S TA N D A R D IMPLEMENTATION EXPERIENCE

Dave Grabaskas Manager, Licensing and Risk Assessments Group, Argonne National Laboratory Chair, ASME/ANS Non -LWR PRA standard working group Former Chair (current Vice Chair), NLWR PRA standard working group JCNRM Background

• Joint Committee on Nuclear Risk Management (JCNRM) o The JCNRM is the PRA Standards development and maintenance consensus committee - formed by combining:

§ ANS RISC committee - originally developing the hazard PRA standards (e.g., Seismic, Fire, Flooding, etc.)

§ ASME CRNM committee - developed the internal events requirements.

o Committees both started in the late 1990s, and officially merged around 2009, and issued the combined standard for LWRs covering L1 PRA, endorsed in RG 1.200.

o Oversees two issued PRA standards (LWR - L1 and Non -LW R )

and five under development.

Standard Background

• Non-LW R P R A S t a n d a r d D e v e l o p m e n t o Working grouped formed in 2006 o Trial use standard issued in 2013 o New version formally approved by ASME, ANS, and ANSI in 2021

§ ASME/ANS/ANSI RA -S-1.4-2021 o Endorsed by the NRC in trial use RG 1.247 in 2022 o An integrated standard:

§ Covers from initiating events to offsite consequence

§ Can include any radionuclide source at the plant

§ From conceptual design to operation Implementation Experience

• NRC Endorsement Process o NRC staff involved throughout the standard development process, which greatly expedited NRC endorsement o Some disagreement regarding certain NRC positions; many resolved through collaboration, others further explored as part of RG trial use period

• User Feedback o Multiple non -LWR vendors are currently utilizing the standard as part of risk-informed performance-based design and licensing approaches, such as the Licensing Modernization Project (LMP) o Continual feedback from vendors regarding implementation experience Implementation Experience

• Standard and Applications o As further experience is gained using the standard for risk-informed applications, potential discrepancies between standard requirements and application requirements are being identified

• Seismic Requirements o Gaining further insight regarding the practicality and implementation details of risk-informed seismic design

• Innovative Uses o Vendors utilizing deterministic or partially risk-informed approaches have been able to leverage certain elements of the standard (initiating events, mechanistic source term, radiological consequence, etc.)

Treatment of extremes in RIPB design

Andrew Whittaker, Ph.D., S.E.

SUNY Distinguished Professor, University at Buffalo Chair, ASCE Nuclear Standards Committee Board of Directors, TerraPraxis Standardization of design and licensing

Li censed desi gn spaces

Pre-bi nned sei smi c hazard (6 zones, 2 soils)

Li censed i solati on systems

1) Si te selected. 2) Pi ck a li censed heat source (M We). 3) Pi ck a li censed i solati on soluti on.

4) Pri ce ti me and constructi on. 5) Evaluate alternati ves and i terate on 2, 3, and 4.

3 Right sizing the treatment of extremes for next generation nuclear

TerraPower and GEH Luci d Catalyst

B WX T Extremes we must rethink in support of RIPB design

• Load effects

• Wi n d-borne missile impact

• Normal impact of high-velocity missiles

• Schedule 40 steel pipe

• Si mple but why normal i mpact?

• Any evidence in non-nuclear sectors of such damage?

• Aircraft impact

• Extreme ground shaking

• Acceptable risk

Stephenson, Terranov a et al.

Extremes we must rethink in support of RIPB design

• Load effects: aircraft impact

• Aircraft cockpits secured for 20 years

• Hijacking of aircraft in US since 2001 = 0

• Strike a RC box and not a political target? No.

• Could you hit the RC box if you wanted to? No. See below.

• MAF of aircraft impact on a RC box in the US = 0 Boei ng

• Guaranteed fatalities from an aircraft strike? Yes

• Missing target = 250+ dead on B787, all on the plane Extremes we must rethink in support of RIPB design

• Load effects: incredible ground shaking

• Consider Seismic Design Category 4, Clinch River

• 100% DRS (PHA=0.53g, RP=5,300 years), 200% DRS (1.06g, 25,000), 400% DRS (2.12g, 150,000), 600% DRS (3.18g, 490,000), 800% DRS (4.24g, 1,250,000)

0.4 4.5 8 DRS

1.5 1982 Miramichi, 2011 Greenbrier, AR, 4.0 Horizontal 0.4 g Vertical 0.4 g 3.5 0.3 6 DRS 2008 Mt. Carmel, 3.0

1 0.2 IL, 0.2 g 2.5 2011 Mineral, VA, 0.2 g 2.0 4 DRS

0.5 1.5 0.1 1.0 2 DRS 0.5 DRS

0 0.0 0.0 0 1 2 3 4 Period (sec) 0 2000 4000 6000 8000 10000 12000 140000 2000 4000 6000 8000 10000 12000 14000 Record sequence number (RSN) Record sequence number (RSN) 7 Outcomes of extreme: nuclear-related fatalities = 0

TMI, 1979

Fukushima Daiichi, 2011 Extremes we must rethink in support of RIPB design

• Societal tolerable risk

• MAF of death in a car accident

• 1/10000 (1E-4)

• MAF of building collapse

• 1/5000 (2E-4)

• MAF of death due to dam failure

• 1/10000 (1E-4), existing dam

• 1/100000 (1E-5), new, major dam

• Need to right size the F-C cha rt awhittak@buffalo.edu Treatment of risk in other sectors: dams

Munger et al. (2009), USA CE

Exi sti ng dams New dams Approach for Risk-Informing IEEE Standards

Rebecca Steinman, PhD, PE Chair: SC-3, WG 3.4 and WG 2.10 09-13-2023 Nuclear Power Engineering Committee (NPEC)

SC-6, 7, 14%

5 Technical Subcommittees

• Qualification (SC-2) SC-2, 18, 35%

• Operations, Maintenance, Aging, SC-5, 7, 14%

Testing & Reliability (SC-3) 51

• Auxiliary Power (SC-4)

• Human Factors, Control Facilities and Human Reliability (SC-5)

SC-4, 11, 21%

• S afet y Re l ate d System s ( S C-6) SC-3, 8, 16%

IEEE 336 IEEE 692 IEEE 338 IEEE 933

IEEE 352 IEEE 1205 IEEE 577 IEEE 1819 NPEC Standards Approach

• Majority of standards focused on design &

qualification of electrica l and electronic equipment

• Class 1E or not, as determined by IEEE 308, 603, and 497

• Class 1E: Safety classification of the electrical equipment and systems that are essential to emergency reactor shutdown, containment isolation, reactor core cooling, and containment and reactor heat removal, or are otherwise essential in preventing significant release of radioactive material to the environment.

IEEE 1819

Risk-Informed Categorization & Treatment of Electrical Equipment

• alternate treatments: Those licensee -defined requirements applied to electrical and electronic systems a nd components (EESCs) that provide reasonable confidence that 1)

RISC-3 EESCs are capable of performing their Class 1E functions under design basis conditions; and 2) RISC -2 EESCs perform their functions consistent with the key assum ptions in the categorization process that relate to their assume d performance, as applicable.

• reasonable assurance: A justifiable level of confidence used to satisfy regulatory requirements, based upon objective and/or measurable evidence.

• reasonable confidence: A level of confidence base d on facts, actions, knowledge, experience, and/or observations, whic h is deemed to be adequate. Reasonable confidence is a lower leve l of confidence than reasonable assurance.

Usage and Status of IEEE Standards

• 10 year revision policy of IEEE

• Desire for global harmonization of standards

• Operating plants stick to their original licensing basis (mostly the 70s and 80s versions)

• Near-term attempts to apply the updated standards often ended up reverting to prior versions because licensing the old standards was "easier"

• So even when we try to modernize a standard to the current state of knowledge we struggle with getting new reactor vendors or other users to commit to their use

The decision to develop a single standard to "bridge the gap" as opposed to significant revision of 50 standards remains the right approach for IEEE.

NEI Codes and Standards Task Force

NRC Standards Forum 2023

Thomas Basso Sr. Director Eng & Risk September 13, 2023

©2023 Nuclear Energy Institute A Risk-Informed Journey

Risk informed approaches have provided a better safety focus, improved safety and enabled efficiencies As we look to the future fleet, there are opportunit ies for risk-informing the regulatory fabric that come with both promise and attention Navigating this change will require embracing uncertaint ies and discipline in responding

©2023 Nuclear Energy Institute 1995 PRA Policy Statement

The use of PRA technology should be increased in all regulatory matters to the extent supported by the state-of -the-art in PRA methods and data and in a manner that complements the NRCs deterministic approach and supports the NRCs traditional defense-in-depth philosophy.

©2023 Nuclear Energy Institute Risk-informed Regulatory Decision-making

Uncertainties PRA Conservative Realism Safety Decisions

Improving the State of the Know ledge

©2023 Nuclear Energy Institute ASME Section XI Code Activities

Code Case N-752 Ris k-informed Repair/Replacement

• NRC Endorsement and Approval of 50.55a(z) Submittals

I WA-4000 Repair /Replacement Optimization

Alternative VT-2 Quali fication

• Establish appropriate training hours requirements

IWE General Visual Examinations (Category E-A, Ite m E1.11) Insulation Removal - Industry Survey

Application of EPRI Tech Bases using PFM for Relief to Extend SG/PRZ Nozzle Weld Inspections

©2023 Nuclear Energy Institute ASME OM Code Activities

Valve Exercising and Testing Requirements

• Valve Manual Exercising Frequency Extension

• Revise Testing of Passive Valve

• Quarterly Valve Stroking Extension

Risk-informed Applications

Replacement of Operability Term in OM

(OM-2) Code on Component Testing Requirements

©2023 Nuclear Energy Institute ASME Section III CSTF Activities

TG Alternative Treatment Requirements

• Code Case on Alternate Requirements for NDE and Testing of Items Commensurate with their Contribution to Safety and Risk

ASME III CC N-907 and Code Change on Preservice Inspection Requirements

Regulatory Engagement on ASME Section III Priorities

©2023 Nuclear Energy Institute NEI CSTF Regulatory Activities

10 CFR 50.55a Rulemaking Review (NRC-2018-0289)

Reg Guides 1.147, 1.84, 1.192, and 1.193 Comments (NRC-2018 -0291)

Extension of 10-year ISI/IST Program Updates Extension of ISI Intervals from 10 to 12 Years

Response to NRC RIS 2022- 02 on Operational Leakage NEI 18-03 Operability Guidance

©2023 Nuclear Energy Institute EPRI Activities Supporting RIPB Standards 2023 NRC Standards Forum

Eric Thornsbury Principal Technical Leader

September 13, 2023

www.epri.com © 2023 Electric Power Research Institute, Inc. All rights reserved.

Introduction

EPRI participates in many activities related to the development of standards across the nuclear industry Interest in Risk-Informed, Performance-Based applications (including standards) has been increasing, and is getting additional attention due to activities related to our Advanced Nuclear Technology program Key Question for Advanced Reactors:

- How to meet current regulations, standards, and other expectations that were developed from a light water reactor perspective?

© 2023 Electric Power Research Institute, Inc. All rights reserved.

Examples of EPRI Activities for the Current Fleet

RPV Threads in Flange (EPRI Report #3002010345)

N715 for Streamlined RI -ISIN (EPRI Report

1. 3002003026 on BWR and PWR Lessons Learned)

ASME Section XI - Appendix R, Supplement 2 was included in the last rulemaking on 50.55a N711 for Inservice Inspection (EPRI Report

1. 3002010353 )

Risk-informed Repair / Replacement (EPRI Report

1. 3002013126) 10CFR50.69 (EPRI Reports #3002012984, 3002012988, 3002012990, 3002022453, 3002015999, )

© 2023 Electric Power Research Institute, Inc. All rights reserved.

Strategic Elements of the EPRI/NEI AR Roadmap

Regulatory Efficiency Technology Readiness Project Execution

Licensing Fuel Cycle Project Management 7 Actions 3 Actions 4 Actions

Environmental Plant/SSC Design Engineering & Procurement 7 Actions 3 Actions 2 Actions

Oversight Supply Chain Construction & Commissioning 2 Actions 7 Actions 3 Actions

Nuclear Beyond Electricity Initial Operations & Maintenance 3 Actions 1 Actions

Codes & Standards Workforce Development 2 Actions 4 Actions

© 2023 Electric Power Research Institute, Inc. All rights reserved.

EPRIs Strengths

Plant Operation & Maintenance Component Manufacturing

• Technical Process Guidance

• Technical Methods Development

• Efficient Tools and Software

• Technology Transfer and Member Support

Standards Development Regulatory Guidance & Interface

© 2023 Electric Power Research Institute, Inc. All rights reserved.

Example: Fuel Qualification from NUREG-2246

© 2023 Electric Power Research Institute, Inc. All rights reserved.

Example: Fuel Qualification for an Advanced Reactor

Geometry for a Liquid Fueled Reactor isdifficult to define!

The fuel does not have a defined geometry of its own What are we really ensuring?

If the intent is to show that we can cool the fuel, perhaps the underlying purpose is that we show that the fuel is in a coolable form (but not necessarily a fixed geometry)

Prescriptive interpretation of this requirement could break down, but RIPB can satisfy the intent!

© 2023 Electric Power Research Institute, Inc. All rights reserved.

Options for Fuel Qualification for a Liquid Fueled Reactor

We could meet it prescriptively with sufficient data, or flexibly with a RIPB approach

Prescriptive: global RIPB: locally large margins based on margins tied to specific highest uncertainty uncertainty

• Prescriptive provides certainty; RIPB provides flexibility to meet the same intent

© 2023 Electric Power Research Institute, Inc. All rights reserved.

EPRI Evaluation of Risk Analysis Methods & Tools for ARs

1. Determine the readiness of current PRA* methods and tools for use in Advanced Reactors and identify technical gaps that can be resolved through EPRI research

2. Develop an EPRI research roadmap to guide EPRI research in this area over the next several years to ensure readiness of PRA methods and tools for Advanced Reactor community implementation

3. Perform research and development based on the first two objectives to resolve key technical gaps in PRA methods and tools for the Advanced Reactor community.

PRA terminology represents a broad range of Risk approaches

© 2023 Electric Power Research Institute, Inc. All rights reserved.

EPRI Evaluation of Risk Analysis Methods & Tools for ARs Challenges Solutions

• Risk analysis is an important input to final designs and initial* Common methods, tools, licensing and data that support

• New technologies used in advanced reactor designs present newrealistic risk analysis in challenges to the existing risk analysis toolset support of design a nd licensing activities

• Risk analysis for advanced reactors is expected to produce* Streamlined risk analysis different results and insights than the current fleet a nd approaches, results, and regulators are familiar with insights that are

• The current risk-informed decision-making approaches may notappropriate for advanced be a realistic approach for advanced reactors reactors

© 2023 Electric Power Research Institute, Inc. All rights reserved.

EPRI Support for the AR Roadmap Action:

Demonstrate Risk-Informed & Performance-Based Approach

Risk Assessments with Digital I&C Systems Data Needs for Evaluate Risk Common Approaches Advanced Reactor Methods & Tools for Passive System Risk Analysis Reliability 2023

Guidance for Guidance for Human Reliability Methods for Selecting Risk Very Low Freq. Analysis Methods Economic Risk Metrics External Events for ARs Analysis

EPRI Report - 3002026495 - Evaluation of Risk Analysis Methods & Tools for Advanced Reactors

© 2023 Electric Power Research Institute, Inc. All rights reserved.

Summary

EPRI supports the development of RIPB standards and related activities RIPB approaches offer the needed focus and flexibility for Advanced Reactors to safely and efficiently design, license, and operation Uncertainties, both technical and regulatory, need to be acknowledged and addressed as part of any RIPB application

© 2023 Electric Power Research Institute, Inc. All rights reserved.

TogetherShaping the Future of Energy

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