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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, RES/DRA/PRB Panelists/Speakers:

Prasad Kadambi (ANS)

David Grabaskas (ASME/ANS JCNRM)

Andrew Whittaker (ASCE)

Rebecca Steinman (IEEE)

Tom Basso (NEI)

Eric Thornsbury (EPRI)

Overview of ANS Activities to Support RIPB Standards N. Prasad Kadambi Chair, Risk-informed, Performance-Based Principles and Policy Committee (RP3C)

Presented to:

2023 NRC Standards Forum September 13, 2023 2

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 ANS consensus committees (CCs) to incorporate RIPB principles where appropriate.

All eight CCs provide reports at every SB meeting.

- The SB recognizes the varied application and applicability of such principles to each portfolio of standards.

- Relative to advanced reactors, the Joint Committee on Risk Management (JCNRM) plays a central role in supporting modernization 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.

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ANS Has Been a Leader in Promoting RIPB VCS

Recent experience with conventional VCS shows that products that have detailed 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 mandated 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.

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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.

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What ANS-2.26 Does ANS-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.

Figure from Appendix A:

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ANS-30.1*

Risk and Performance Objectives (Linn)

ANS-20.2 Liquid Molten Salt Reactor (Holcomb)

ANS-53.1 Modular Helium Cooled Reactor (August)

ANS-54.1 Liquid Sodium Cooled Reactor (Flanagan)

ANS-30.3 Advanced Light-Water Reactor (Welter)

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

ANS and other SDO standards as needed:

- Cross cutting topics

- Reactor technology specific issues Advanced Reactor Large Light Water Rx ANS Standards Committee Hierarchy For Advanced Reactors

ANS-30.1 is now being prepared as an ANS guidance standard, not as an ANSI consensus standard 7

NRC activities support RIPB, but more can be done.

Commission approval of SECY-18-0096 [9] on Functional Containment has major significance for RIPB standards as an example of performance-based principles.

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

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

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

NRC should recognize that industry and SDOs alike look for regulatory cues that may encourage 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.

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ADDITIONAL INFORMATION 9

The ANS Standards Committee Standards Board (Top-level committee)

Large Light Water Reactors Consensus Committee (LLWRCC)

Research and Advanced Reactors Consensus Committee (RARCC)

Safety &

Radiological Analyses Consensus Committee (SRACC)

Nonreactor Nuclear Facilities Consensus Committee (NRNFCC)

Joint Committee on Nuclear Risk Management (JCNRM*)

Consensus Committee Nuclear Criticality Safety Consensus Committee (NCSCC)

Environmental and Siting Consensus Committee (ESCC)

Fuel, Waste, and Decommissioning Consensus Committee (FWDCC)

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

The JCNRM is a joint ANS and ASME committee.

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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.

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[1]

OMB Circular A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and in 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 Titles of Cited Documents and Standards 12

ASME/ANS NON-LWR PRA STANDARD 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 13

JCNRM Background

Joint Committee on Nuclear Risk Management (JCNRM) oThe 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.

oCommittees 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.

oOversees two issued PRA standards (LWR - L1 and Non-LWR) and five under development.

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Standard Background

Non-LWR PRA Standard Development oWorking grouped formed in 2006 oTrial use standard issued in 2013 oNew version formally approved by ASME, ANS, and ANSI in 2021

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

§ Covers from initiating events to offsite consequence

§ Can include any radionuclide source at the plant

§ From conceptual design to operation 15

Implementation Experience

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

User Feedback oMultiple 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) oContinual feedback from vendors regarding implementation experience 16

Implementation Experience

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

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

Innovative Uses oVendors 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.)

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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 18

Standardization of design and licensing Licensed design spaces Pre-binned seismic hazard (6 zones, 2 soils)

Licensed isolation systems

1) Site selected. 2) Pick a licensed heat source (MWe). 3) Pick a licensed isolation solution.

4) Price time and construction. 5) Evaluate alternatives and iterate on 2, 3, and 4.

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3 Lucid Catalyst TerraPower and GEH Right sizing the treatment of extremes for next generation nuclear BWXT 20

Extremes we must rethink in support of RIPB design

Load effects Wind-borne missile impact Normal impact of high-velocity missiles Schedule 40 steel pipe Simple but why normal impact?

Any evidence in non-nuclear sectors of such damage?

Aircraft impact Extreme ground shaking

Acceptable risk Stephenson, Terranova et al.

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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 Guaranteed fatalities from an aircraft strike? Yes Missing target = 250+ dead on B787, all on the plane Boeing 22

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 1

2 3

4 Period (sec) 0 0.5 1

1.5 Sa (g)

Horizontal Vertical 2008 Mt. Carmel, IL, 0.2 g 2011 Greenbrier, AR, 0.4 g 2011 Mineral, VA, 0.2 g 1982 Miramichi, 0.4 g 0.0 0.1 0.2 0.3 0.4 0

2000 4000 6000 8000 10000 12000 14000 PGA, H (g)

Record sequence number (RSN) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 0

2000 4000 6000 8000 10000 12000 14000 PGA, H (g)

Record sequence number (RSN)

DRS 2 DRS 4 DRS 6 DRS 8 DRS 23

7 Outcomes of extreme: nuclear-related fatalities = 0 Fukushima Daiichi, 2011 TMI, 1979 24

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 chart 25

awhittak@buffalo.edu 26

Treatment of risk in other sectors: dams Existing dams New dams Munger et al. (2009), USACE 27

Approach for Risk-Informing IEEE Standards Rebecca Steinman, PhD, PE Chair: SC-3, WG 3.4 and WG 2.10 09-13-2023 28

5 Technical Subcommittees Qualification (SC-2)

Operations, Maintenance, Aging, Testing & Reliability (SC-3)

Auxiliary Power (SC-4)

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

Safety Related Systems (SC-6)

Nuclear Power Engineering Committee (NPEC)

SC-2, 18, 35%

SC-3, 8, 16%

SC-4, 11, 21%

SC-5, 7, 14%

SC-6, 7, 14%

51 IEEE 336 IEEE 692 IEEE 338 IEEE 933 IEEE 352 IEEE 1205 IEEE 577 IEEE 1819 29

NPEC Standards Approach

Majority of standards focused on design &

qualification of electrical 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.

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Risk-Informed Categorization & Treatment of Electrical Equipment

alternate treatments: Those licensee-defined requirements applied to electrical and electronic systems and 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 assumptions in the categorization process that relate to their assumed 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 based on facts, actions, knowledge, experience, and/or observations, which is deemed to be adequate. Reasonable confidence is a lower level of confidence than reasonable assurance.

IEEE 1819 31

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. 32

©2023 Nuclear Energy Institute Risk informed approaches have provided a better safety focus, improved safety and enabled efficiencies As we look to the future fleet, there are opportunities for risk-informing the regulatory fabric that come with both promise and attention Navigating this change will require embracing uncertainties and discipline in responding A Risk-Informed Journey 34

©2023 Nuclear Energy Institute 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.

1995 PRA Policy Statement 35

Code Case N-752 Risk-informed Repair/Replacement NRC Endorsement and Approval of 50.55a(z) Submittals

IWA-4000 Repair/Replacement Optimization

Alternative VT-2 Qualification Establish appropriate training hours requirements

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

Application of EPRI Tech Bases using PFM for Relief to Extend SG/PRZ Nozzle Weld Inspections 37

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 38

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 ASME Section III CSTF Activities 39

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 40

w w w. e p r i. c o m Eric Thornsbury Principal Technical Leader September 13, 2023 EPRI Activities Supporting RIPB Standards 2023 NRC Standards Forum 41

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?

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Examples of EPRI Activities for the Current Fleet RPV Threads in Flange (EPRI Report #3002010345)

N715 for Streamlined RI-ISIN (EPRI Report

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

3002010353 )

Risk-informed Repair / Replacement (EPRI Report

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

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Strategic Elements of the EPRI/NEI AR Roadmap Regulatory Efficiency Licensing 7 Actions Environmental 7 Actions Oversight 2 Actions Technology Readiness Fuel Cycle 3 Actions Plant/SSC Design 3 Actions Supply Chain 7 Actions Nuclear Beyond Electricity 3 Actions Codes & Standards 2 Actions Project Execution Project Management 4 Actions Engineering & Procurement 2 Actions Construction & Commissioning 3 Actions Initial Operations & Maintenance 1 Actions Workforce Development 4 Actions 44

EPRIs Strengths

Technical Process Guidance

Technical Methods Development

Efficient Tools and Software

Technology Transfer and Member Support Standards Development Regulatory Guidance & Interface Plant Operation & Maintenance Component Manufacturing 45

Example: Fuel Qualification from NUREG-2246 46

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!

Example: Fuel Qualification for an Advanced Reactor 47

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

Prescriptive provides certainty; RIPB provides flexibility to meet the same intent 48

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 49

EPRI Evaluation of Risk Analysis Methods & Tools for ARs

Common methods, tools, and data that support realistic risk analysis in support of design and licensing activities

Streamlined risk analysis approaches, results, and insights that are appropriate for advanced reactors Challenges

Risk analysis is an important input to final designs and initial licensing

New technologies used in advanced reactor designs present new challenges to the existing risk analysis toolset

Risk analysis for advanced reactors is expected to produce different results and insights than the current fleet and regulators are familiar with

The current risk-informed decision-making approaches may not be a realistic approach for advanced reactors Solutions 50

EPRI Support for the AR Roadmap Action:

Demonstrate Risk-Informed & Performance-Based Approach 2023 Human Reliability Analysis Methods for ARs Guidance for Very Low Freq.

External Events Evaluate Risk Methods & Tools Risk Assessments with Digital I&C Systems Guidance for Selecting Risk Metrics Common Approaches for Passive System Reliability Methods for Economic Risk Analysis Data Needs for Advanced Reactor Risk Analysis EPRI Report - 3002026495 - Evaluation of Risk Analysis Methods & Tools for Advanced Reactors 51

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 52

TogetherShaping the Future of Energy 53

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