ML22165A114

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NRC Staff Presentation Slides for Public Meeting Regarding 10 CFR Part 53 Licensing and Regulation of Commercial Nuclear Plants Framework B - Preliminary Proposed Rule Language Overview Including Alternate Evaluation of Risk Insights
ML22165A114
Person / Time
Issue date: 06/16/2022
From: Robert Beall
NRC/NMSS/DREFS/RRPB
To:
Beall, Robert
References
10 CFR Part 53, NRC-2019-0062, RIN 3150-AK31
Download: ML22165A114 (43)
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Text

Par t 5 3 F ram ewo rk B O ve r v i ew Public Meeting 6/16/22

Agenda

  • Overview of Part 53 Structure
  • Comparison of Part 53 Frameworks
  • Framework B Development Approach
  • Framework B Subparts Overview
  • Alternative Evaluation of Risk Insights (AERI)
  • Next steps 2

Welcome and Introductions Welcome:

Rob Taylor, Office of Nuclear Reactor Regulation NRC Speakers / Presenters:

Office of Nuclear Material Safety and Safeguards

  • Bob Beall Office of Nuclear Reactor Regulation
  • Bill Jessup
  • Marty Stutzke

ADAMS Accession No. ML22165A114 3

Purpose of Todays Meeting

  • Overview of the Part 53 proposed Framework B rulemaking effort.
  • Todays meeting is a Comment-Gathering meeting, which means that public participation is actively sought in the discussion of the regulatory issues during the meeting.
  • The meeting is being transcribed and the transcription will be available with the meeting summary by July 16, 2022.
  • No regulatory decisions will be made at todays meeting.

4

Part 53 Licensing Subpart B - Safety Requirements Frameworks Subpart C - Design Requirements Framework A o Probabilistic risk assessment Subpart D - Siting (PRA)-led approach Subpart E - Construction/Manufacturing o Functional design criteria Subpart F - Operations Subpart G - Decommissioning Subpart H - Application Requirements Subpart I - License Maintenance Subpart J - Reporting Subpart K - Quality Assurance Subpart A - General Provisions Framework B Subpart N - Definitions o Traditional use of risk insights Subpart O - Construction/Manufacturing o Principal design criteria Subpart P - Operations o Includes an AERI approach Subpart Q - Decommissioning Subpart R - Application Requirements Subpart S - License Maintenance Subpart T - Reporting 5

Subpart U - Quality Assurance

Part 53 Subpart Comparison Framework A Framework B Subpart Title Subpart Subpart General Provisions Subpart A (Common)

Technology-Inclusive Safety Requirements Subpart B Design and Analysis Requirements Subpart C Siting Requirements Subpart D (Part 100)

Definitions - Subpart N Construction and Manufacturing Requirements Subpart E Subpart O Requirements for Operation Subpart F Subpart P Decommissioning Requirements Subpart G Subpart Q Licenses, Certifications, and Approvals Subpart H Subpart R Maintaining and Revising Licensing Basis Information Subpart I Subpart S Reporting and Other Administrative Requirements Subpart J Subpart T Quality Assurance Criteria Subpart K Subpart U 6

Framework B Development Approach 7

Subpart N - Definitions

  • Common definitions remain in Subpart A (§ 53.020) 8

Subpart O - Construction and Manufacturing Requirements

  • Parallel structure and content to Framework A Subpart E
  • Variations largely limited to conforming changes needed to adapt Framework A provisions to Framework B 9

Subpart P - Requirements for Operation

§ 53.4210 Maintenance, repair, and inspection programs.

§ 53.4213 Technical specifications.

General staffing, training, personnel qualifications, and human factors

§§ 53.4220 - 53.4299 requirements.

§ 53.4300 Programs.

§ 53.4310 Programs: Radiation protection.

§ 53.4320 Programs: Emergency preparedness.

§ 53.4330 Programs: Security programs.

§ 53.4340 Programs: Quality assurance.

§ 53.4350 Programs: Fire protection.

§ 53.4360 Programs: Inservice inspection/inservice testing.

§ 53.4380 Programs: Environmental qualification of electric equipment

§ 53.4390 Programs: Procedures and guidelines.

§ 53.4400 Programs: Integrity assessment program.

§ 53.4410 Programs: Primary containment leakage rate testing program.

10

Subpart P - Requirements for Operation

  • Maintenance, repair, and inspection programs generally aligned with § 50.65
  • Technical specifications generally aligned with § 50.36
  • Programs o Security, Emergency Preparedness, Radiation Protection requirements aligned with Framework A o Environmental qualification of electrical equipment derived from § 50.49 o Scope of SSCs in Integrity Assessment Program aligned more closely with

§ 53.4210(b) (§ 50.65(b))

o Containment leak rate requirements from Part 50 (§ 50.54(o))

11

Subpart P - Requirements for Operation Staffing, Training, Personnel Qualifications, and Human Factors

  • Framework B adopts most requirements from Framework A through cross-references or copying requirements with some minor changes
  • Staffing plan requirements in § 53.4226(f) include the need for engineering expertise availability to support on-shift operating personnel o Must be familiar with facility operation and meet at least one educational or credential requirement in §§ 53.4226(f)(1)(i) through (f)(1)(iii) o Developed in response to ACRS feedback on blanket removal of shift technical advisor position
  • Framework A's provisions for alternatives to the use of licensed Reactor Operators and Senior Reactor Operators are not currently translated to Framework B; the staff will continue to evaluate options in this area 12

Subpart P - Requirements for Operation Fire Protection

  • Combination of § 50.48, Appendix R, and NFPA 805 Chapter 3 o All requirements are contained in in-line rule text No appendices in Part 53 No cross-references back to Parts 50 or 52
  • No fire PRA required, but may be useful in performance-based justifications o Provision for performance-based alternatives to detailed requirements with NRC approval (like § 50.48(c)(2)(vii) and § 50.48(c)(4))
  • Technology neutral o Designers must define the safe and stable state for their design o Designers must determine the safe shutdown functions to achieve and maintain safe and stable state 13

Subpart Q - Decommissioning Requirements

  • Parallel structure and content to Framework A Subpart G
  • Variations largely limited to conforming changes needed to adapt Framework A provisions to Framework B 14

Subpart S -

  • Parallel structure and content to Framework A Subpart I Maintaining
  • Notable differentials and Revising o § 53.6010, Application for amendment of license Licensing Basis o § 53.6040, Updating licensing basis information and determining the need for NRC approval Information o § 53.6045, Updating final safety analysis reports o § 53.6050, Evaluating changes to facility as described in final safety analysis reports o § 53.6052, Maintenance of risk evaluations
  • Remaining variations largely limited to conforming changes to adapt Framework A provisions to Framework B 15

Subpart T - Reporting and Other Administrative Requirements

  • Parallel structure and content to Framework A Subpart J
  • Notable differentials o § 53.6320(e) added to align with state-of-practice policy initiative on reporting requirement for fee purposes o § 53.6330, Immediate notification requirements for operating commercial nuclear plants, aligned with § 50.72 o § 53.6340, Licensee event report system, aligned with § 50.73
  • Remaining variations largely limited to conforming changes to adapt Framework A provisions to Framework B 16
  • Subpart U parallels structure and content of Framework A Subpart K
  • Exception: § 53.6635, Control of Subpart U - Quality Purchased Material, Equipment and Assurance Services (10 CFR Part 50 Appendix B Criterion VII) o Commercial nuclear plant used in lieu of nuclear power plant o Ensures consistency with terminology throughout Part 53 17

Subpart R - Licenses, Certifications, and Approvals

§ 53.4700 General Provisions.

§ 53.4725 Standards for review.

§ 53.4730 General technical requirements.

§ 53.4731 Risk-informed classification of structures, systems, and components.

§ 53.4740 Limited work authorizations.

§ 53.4750 Early site permits.

§ 53.4800 Standard design approvals

§ 53.4830 Standard design certifications.

§ 53.4870 Manufacturing licenses.

§ 53.4900 Construction permits.

§ 53.4960 Operating licenses.

§ 53.5010 Combined licenses. 18

Subpart R - Licenses, Certifications, and Approvals

  • Subpart R developed to parallel Subpart H in Framework A o Covers all application types (e.g., Construction Permit (CP), Operating License (OL), Combined License (COL))

o Process-related requirements (e.g., duration of a license) similar or the same between frameworks o Technical contents of application structures derived from Parts 50 and 52 and represent primary differentiator between Subparts H and R o Includes § 53.4731 that parallels § 50.69 regarding risk-informed SSC classification 19

Subpart R - Licenses, Certifications, and Approvals Application Type

  • Section § 53.4730, General technical requirements, consolidates technical content of application requirements COL OL CP ML DC SDA ESP for the various application types o COL technical contents of (1) X X X X X X X application (§ 52.79) used as a 53.4730(a) starting point (2) X X X X X X X o Each application type references (3) X X X X X X Requirement back to § 53.4730 Reduces rule length Minimizes the potential for requirements to diverge between (37) X X X X X X X application types 20

Subpart R - Licenses, Certifications, and Approvals Accident Analyses and Initiating Event Requirements

  • Requirements in § 53.4730(a)(5) derived from previous Part 5X work undertaken in 2021 that proposed technology-inclusive alternatives to some requirements in Parts 50 and 52
  • AOOs (§ 53.4730(a)(5)(iii)): Requirements consistent with existing requirements in traditional frameworks with Part 20 acceptance criteria
  • Design Basis Accidents (DBAs) (§ 53.4730(a)(5)(ii)): New technology-neutral requirements for DBA analyses and SSC classification based loosely on §§ 50.34(a)(4) and 50.46
  • Beyond Design Basis Events (BDBEs) (§ 53.4730(a)(5)(iv)): Provides technology-inclusive requirements for relevant BDBEs and analysis requirements for other BDBEs, drawn from Anticipated Transient Without Scram/Station Black Out rulemakings; similar to international defense in depth requirements.
  • Severe Accidents (§ 53.4730(a)(5)(v)): Derived from current requirements in § 52.79(a)(38), with modifications made to support technology-inclusiveness
  • Chemical Hazards (§ 53.4730(a)(5)(vi)): Requirements based on language proposed in Framework A to address potential chemical hazards associated with licensed material 21

Subpart R - Licenses, Certifications, and Approvals Assessing Risk in Framework B

  • Risk insights support or complement deterministic analyses, consistent with traditional approach
  • Includes requirement to provide a description of the plant-specific PRA and its results translated to Framework B

§ 52.79(a)(44) § 53.4730(a)(34)(i)

  • Optional alternative risk evaluation for applicants that meet the criteria in § 53.4730(a)(34)(ii) o No PRA required o Implicitly demonstrates that quantitative health objectives (QHOs) are met, searches for severe accident vulnerabilities, and provides risk insights without a requirement for a PRA o Inherently addresses the mitigation of beyond-design-basis events requirements when AERI entry criteria are met o Cannot implement risk-informed applications if AERI approach is used
  • Risk evaluations (PRA or AERI) must be maintained consistent with requirements in Subpart S

(§ 53.6052, informed by § 50.71(h))

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Alternative Evaluation for Risk Insights

  • Evolved from the staffs graded PRA initiative starting in Spring 2021 o Grade the technical content of the PRA o Grade the uses of the PRA in the design and licensing process PRA in an enhanced/leading role PRA in a supporting/confirmatory/traditional role
  • Various names have been used to describe the concept:

o Dose/consequence-based approach o Technology-inclusive, risk-informed maximum accident (TIRIMA) approach o Part 53-BE (bounding event) o AERI 23

Uses of PRA

  • The Policy Statement on the Regulation of Advanced Reactors (73 FR 60612; October 14, 2008) references three PRA-related policy statements:

o Safety Goals for the Operation of Nuclear Power Plants (51 FR 28044; August 4, 1986 as corrected and republished at 51 FR 30028; August 21, 1986)

Meet the QHOs o Severe Reactor Accidents Regarding Future Designs and Existing Plants (50 FR 32138; August 8, 1985)

Search for severe accident vulnerabilities o Use of Probabilistic Risk Assessment Methods in Nuclear Regulatory Activities (60 FR 42622; August 16, 1995)

Identify risk insights

  • The AERI approach and two pre-decisional draft regulatory guides (PDGs) have been developed to:

o Provide sufficient risk information to inform licensing decisions o Address related ACRS recommendations 24

ACRS Recommendations

  • October 7, 2019 - Letter concerning review of draft SECY paper, "Population - Related Siting Considerations for Advanced Reactors," ML19277H071:

o Need to examine new designs with a clean sheet of paper.

o Think carefully about the failures and combinations of failures that could occur.

o Must remain vigilant and remember that nature provides surprises.

o Creative thinking will be required to identify such unique situations, to thoroughly identify the scenarios that will be the basis of the safety analysis and the source of releases, and to evaluate the suitability of sites.

o Compensate for novel designs with uncertainties due to incompleteness in the knowledge base by performing systematic searches for hazards, initiating events, and accident scenarios with no preconceptions that could limit the creative process.

  • May 5, 2021 - Letter concerning Part 53, ML21140A354:

o Compensate for novel designs with uncertainties due to incompleteness in the knowledge base by performing systematic searches for hazards, initiating events, and accident scenarios with no preconceptions that could limit the creative process.

  • October 26, 2021 - Letter concerning RG 1.247, ML21288A018:

o Include guidance that the initial search for initiating events and scenarios should be done 25 without preconceptions or using existing lists.

Licensing Frameworks - Risk Evaluation Perspective H I Parts 50 and 52 with LMP Perform Perform design basis Continue design transient and accident radiological and licensing Part 53 Framework A accident analyses consequences analyses activities C D E F Finish PRA Select LBEs Select DBAs Classify SSCs development G

A Evaluate Comprehensive defense-in-and systematic depth initiator search and event B Select Notes:

sequence 1) Each step builds on all of the preceding steps (considers all information available at that point) licensing delineation framework 2) Feedback loops (e.g., the impact of design revisions) are not shown without preconceptions J K L M N or reliance on Select Perform Perform design basis yes Continue design Elect to Finish PRA predefined lists licensing transient and accident radiological and licensing develop PRA development events accident analyses consequences analyses activities Q

Parts 50 and 52 without LMP no AERI Part 53 Framework B ONLY for Part 53 Q1 - Develop demonstrably Framework B no conservative risk estimate Applicant decision using the bounding event O P Identify and yes Continue design AERI entry Q2 - Search all event PDG-1413, Technology-Inclusive Identification of Licensing Events for analyze the and licensing conditions met? sequences for severe Commercial Nuclear Plants bounding event activities accident vulnerabilities PDG-1414, Alternative Evaluation for Risk Insights (AERI) Framework Q3 - Develop risk insights by AERI reviewing all event sequences 26 Licensing Modernization Project (LMP) guidance - NEI 18-04, Rev. 1, as endorsed in RG 1.233 26

Proposed AERI Entry Conditions 53.4730(a)(34) Description of risk evaluation.

A description of the risk evaluation developed for the commercial nuclear plant and its results. The risk evaluation must be based on:

(i) A PRA, or (ii) An AERI, provided that the dose from a postulated bounding event to an individual located 100 meters (328 feet) away from the commercial nuclear plant does not exceed 1 rem total effective dose equivalent (TEDE) over the first four days following a release, an additional 2 rem TEDE in the first year, and 0.5 rem TEDE per year in the second and subsequent years.

  • Provides plants with flexibility in establishing their exclusion area boundaries if the bounding events source term is small.
  • The 100-meter criterion was back-calculated from a scoping consequence model:

o 50-year dose at 100 meters = 27.5 rem TEDE o Conditional individual latent cancer fatality risk = 2 x 10-6 per event o Meet the QHO without developing a PRA to credit accident frequency in the risk estimate

  • Some stakeholders have confused the AERI entry conditions with safety/siting criteria.

27

Technology-Inclusive Identification of Licensing Events for Commercial Nuclear Plants (Pre-decisional DG-1413)

  • Formatted like a regulatory guide; currently a pre-decisional draft regulatory guide
  • Section A: Applies to light water reactors (LWRs) and non-LWRs licensed under Parts 50, 52, and 53 (Frameworks A and B)
  • Section B:

o Identifies licensing events for each licensing framework o Provides historical perspectives (early licensing, development of the standard review plan) o Addresses ACRS recommendations to start with a blank sheet of paper (10/7/2019, 10/21/2020, 5/30/2021, and 10/26/2021)

  • Section C provides an integrated approach for:

o Conducting a systematic and comprehensive search for initiating events o Delineating a systematic and comprehensive sets of event sequences o Grouping the lists of initiating events and event sequences into licensing events

  • Appendix:

o Recommends the use of one inductive method and one deductive method when searching for initiating events o Points the user to helpful references (NRC, IAEA, IEC, ASME/ANS, AIChE, EPRI, open literature) o Does not endorse or recommend any specific method 28

Alternative Evaluation for Risk Insights (AERI) Framework (Pre-decisional DG-1414)

  • Formatted like a regulatory guide; currently a pre-decisional draft regulatory guide
  • Section A: Only applies to LWRs and non-LWRs licensed under Part 53 Framework B
  • Sections B & C: Components of the AERI approach:

o Identification and characterization of the bounding event o Definition of a bounding event Multiple events may need to be considered as bounding events o Determination of a consequence estimate for the bounding event to confirm that the reactor design meets the AERI entry conditions o Determination of a demonstrably conservative risk estimate for the bounding event to demonstrate that the QHOs are met Assumed frequency of 1/yr consistent with frequency of all event sequences for LWRs Applicant may use a lower frequency with justification o Search for severe accident vulnerabilities for the entire set of licensing events Definitions of severe accident and severe accident vulnerability o Identification of risk insights for the entire set of licensing events o Assessment of defense-in-depth adequacy for the entire set of licensing events 29

Many Framework A and B guidance development activities are linked Framework B May involve updates or supplements Guidance to existing guidance covering existing regulatory frameworks Development Guidance for technical content of application requirements now part of Advanced Reactor Content of Application Project effort 30

Areas of Focus for Merger of Frameworks A and B Ensure consistency between parallel provisions Evaluate other provisions for potential alignment

  • Siting
  • Seismic Design Criteria
  • Requirements for Operation Commonalities in Subpart A
  • Definitions
  • General Provisions Continue consideration of stakeholder feedback 31

Next Steps Advisory Committee on Reactor Safeguards

  • Subcommittee:

June 23 - 24, 2022

  • Full Committee:

July 6 - 9, 2022 Advanced Reactor Public Stakeholder Meeting:

June 30, 2022 Commission Meeting:

July 21, 2022 32

Additional Information Additional information on the 10 CFR Part 53 rulemaking is available at https://www.nrc.gov/reactors/new-reactors/advanced/rulemaking-and-guidance/part-53.html For information on how to submit comments go to https://www.regulations.gov and search for Docket ID NRC-2019-0062 For further information, contact Robert Beall, Office of Nuclear Material Safety and Safeguards, telephone: 301-415-3874; email:

Robert.Beall@nrc.gov 33

Acronyms IAEA International Atomic Energy Agency ACRS Advisory Committee on Reactor Safeguards IEC The Incident and Emergency Centre Agencywide Documents Access and LBE Licensing basis event ADAMS Management System LMP Licensing Modernization Project AERI Alternative evaluation of risk insights LWR Light water reactor AIChe American Institute of Chemical Engineers ML Manufacturing license ANS American Nuclear Society NEI Nuclear Energy Institute AOO Anticipated operational occurrence NFPA National Fire Protection Association ASME American Society of Mechanical Engineers NRC U.S. Nuclear Regulatory Commission BDBE Beyond design basis event OL Operating license BE Bounding event PDG Pre-decisional draft regulatory guide CFR Code of Federal Regulations PRA Probabilistic risk assessment COL Combined license QHO Quantitative health objective CP Construction permit RG Regulatory guide DBA Design basis accident SDA Standard design approval DC Design certification SSCs Structures, systems, and components EPRI Electric Power Research Institute TEDE Total effective dose equivalent ESP Early site permit Technology-inclusive, risk-informed maximum 34 TIRIMA FR Federal Register accident

Backup Slides 35

Regulatory Framework Options Framework B: Emphasis Design Criteria Framework A: Emphasis Risk Metrics and Insights

  • Traditional approach represented by figure from
  • With addition of DBA used to set design criteria IAEA guidance. and performance objectives for the design of 36 Safety Related SSCs.

Derivation of AERI Entry Conditions (1 of 7) 1 Risk, R, is the sum of the products of frequency, , and consequence, ,

over the set of delineated event sequences.

2 Suppose we can identify a bounding event. max , ,,

3 Then we can bound the risk.

4 This demonstrably conservative approach

= sum of the initiating event frequencies eliminates the need to estimate the individual 1/plant-year, based on large LWR history event sequence frequencies by developing a PRA.

37

Derivation of AERI Entry Conditions (2 of 7) 5 There are two quantitative health objectives (QHOs):

  • Individual early fatality risk (IEFR) 5 10
  • Individual latent cancer fatality risk (ILCFR) 2 10 Justification for these values is provided in NUREG-0880, Rev. 1, pp. 30-31.

6 Focus on ILCFR: = conditional latent cancer fatality risk,

  • Part 53, Framework B has been developed to provide , of the bounding event the same level of safety as currently operating plants.
  • The State-of-the-Art Reactor Consequence Analysis 1 2 10 (SOARCA) studies indicate that IEFR is essentially zero.

7

= expected number of latent cancer fatalities within 10 miles of the site over 50 years following occurrence of the bounding event CILCFR

= total population within 10 miles of the site 38

Derivation of AERI Entry Conditions (3 of 7) 8 Assume that the plume is confined to one of sixteen 22.5-degree sectors.

22.5° 8

= expected number of latent cancer fatalities in the 10-mile, 22.5° sector over 50 years following occurrence 1 1 10 of the bounding event 9

This assumption eliminates the Assume a uniform population density, .

need to consider the wind direction 39

Derivation of AERI Entry Conditions (4 of 7) 10 On a differential basis, the number of latent cancer fatalities is a random variable that is characterized by a binomial probability distribution:

= probability that an individual located

~ ,

at distance r dies within 50 years Accordingly, the expected (mean) value is: = differential number of individuals in the 22.5° sector that are located

  • between r and r + dr 11 Apply the linear no-threshold model, which relates = risk coefficient (per rem) cumulative radiation exposure to fatality risk. 6 10 according to BEIR-VII*

= 50-year dose at distance r (rem)

The Commission affirmed the NRCs use of the *National Research Council. 2006. Health Risks from Exposure LNT model in SRM-SECY-19-0008, July 16, 2021. to Low Levels of Ionizing Radiation: BEIR VII Phase 2.

Washington, DC: The National Academies Press.

https://doi.org/10.17226/11340.

40

Derivation of AERI Entry Conditions (5 of 7) 12 Assume a power-law dose vs. distance model:

Consistent with NUREG-0396, Planning Basis for the Development of State and Local Government The subscript 0 refers to an arbitrary Radiological Emergency Response Plans in Support of reference location and dose. Light Water Nuclear Power Plants, November 1978.

13

  • Integrate over the 10-mile area surrounding the site.

. 1 Apply the uniform population density, LNT, and power-

  • * *2 law dose vs. distance assumptions.

16

. = expected number of latent cancer fatalities in 10 the 10-mile, 22.5° sector over 50 years following 4 occurrence of the bounding event 41

Derivation of AERI Entry Conditions (6 of 7) 14 The total population in the 10-mile area is: Apply the uniform population density assumption.

  • 10 20 5 15 Scoping consequence model.

10 80 5 Note: decreases as increases.

16 10 Upper bound of the scoping consequence model 400 400

  • 0.422 Criterion for the reference point 10 42

Derivation of AERI Entry Conditions (7 of 7) 17 Dose (rem TEDE) Condition 1 First 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> Additional dose 2

during the 1st year Additional dose 0.5 x 49 = 24.5 during the second and subsequent years 27.5 TOTAL Note: The reference location is not necessarily the same as the EAB 43

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