ML21158A223

Meeting Summary for Ticap Workshop #3

ML21158A223
Person / Time
Site:	Grand Gulf, Arkansas Nuclear, River Bend, Waterford
Issue date:	06/08/2021
From:	Eric Oesterle NRC/NRR/DANU/UARP
To:	John Segala NRC/NRR/DANU/UARP
Oesterle E
References
Download: ML21158A223 (29)

Text

June 8, 2021 MEMORANDUM TO: John P. Segala, Chief Advanced Reactor Policy Branch Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation Digitally signed by Eric R.

FROM: Eric R. Oesterle, Senior Project Manager Eric R. Oesterle Oesterle Advanced Reactor Policy Branch Date: 2021.06.09 11:14:09 -04'00' Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation

SUMMARY

OF MAY 26, 2021, PUBLIC MEETING TO DISCUSS TECHNOLOGY INCLUSIVE CONTENT OF APPLICATION PROJECT On May 26, 2021, the U.S. Nuclear Regulatory Commission (NRC) staff held a public meeting with stakeholders, to discuss the technology inclusive content of application project (TICAP).

The meeting notice is available in the NRCs Agencywide Documents Access and Management System (ADAMS) at Accession No. ML21144A002, and the presentation slides are available at ADAMS Accession No. ML21146A088. The Enclosure 1 to this summary provides the attendees for the meeting as captured by Microsoft Teams.

Meeting Highlights The meeting was in the form of a workshop. The purpose of the workshop was to discuss industrys draft TICAP guidance document found at ADAMS Accession No. ML21106A013. Prior to the workshop the NRC staff identified a list of 23 items that were identified as topics to be discussed during this workshop and remaining TICAP workshop scheduled for May 26, 2021. The list of issues can be found at ADAMS Accession No. ML21120A057. Thirteen of the 23 items were discussed during the May 11, 2021 workshop (see meeting summary at ADAMS Accession No. ML21132A295) and seven of the 23 items were discussed during the May 19, 2021 workshop (see meeting summary at ADAMS Accession No. ML21154A290). A path forward for several of the issues discussed during workshop was identified. Enclosure 2 documents the results of the workshop in the disposition column.

CONTACT: Oesterle Eric UARP/DANU (301) 415-1014

J .Segala Two topical areas were identified during this workshop for further focused discussion towards resolution of the content of the TICAP guidance discussions needed for these topics:

Topic 9, reliability and capability targets, from the list found in Enclosure 2. This issue was originally identified as an outcome of the TICAP tabletop exercises that were held in the February through March 2021 time frame. The observations from these TICAP tabletop exercises can be found at ADAMS Accession No. ML21125A139.

The NRC staff noted that industrys draft TICAP guidance document does not appear to be consistent with NEI 18-04, Rev 1, Risk-Informed Performance-Based Technology Guidance for Non-Light Water Reactors, (ADAMS Accession No. ML19241A336) in that the reliability and capability targets are not proposed to be captured in the safety analysis report (SAR). From the staffs perspective the SAR should describe reliability targets and performance requirements used as input to the probabilistic risk assessment and for structures, systems and components that were used to develop the selection of special treatment requirements (i.e., programmatic actions used to maintain performance within the design reliability targets). The staff noted this information is important to capture in the SAR and in some cases could also be captured as part of technical specification requirements. From the industrys perspective, there is a concern that placing such information in the SAR is unnecessary and would potentially create a burden from a change control process standpoint. The staff and industry agreed to discuss this issue further in a future focused meeting.

Topic 6 from the list found in Enclosure 2 associated with the development of principal design criteria (PDC).

The staff believes the TICAP approach to establishing the RFDC as the PDC is too narrow.

The staff believes the following statement is not correct For plants that use the NEI 18-04 methodology, the PDC that flows from the LMP methodology and are needed to support the LMP-based safety case are based on the RSFs and the Required Functional Design Criteria (RFDC). RFDCs are used to supplement or modify ARDCs in developing PDCs. RG 1.232 should be referenced since there are other PDCs that are not tied to RFDCs (e.g., ARDCs 1 through 4). NEI 18-04 4.1 Task 7 states: RFDCs are defined to capture design-specific criteria that may be used to supplement or modify the applicable General Design Criteria or Advanced Reactor Design Criteria in the formulation of Principal Design Criteria.

Industry does not believe the intent of NEI 18-04 was to impose deterministic PDC on a risk-informed, performance-based process. The TICAP methodologies are trying to adapt the PDC concept to the affirmative safety case approach and equate the PDC to those associated with RSFs. In that approach, considering non-reactor sources could have associated RSFs and PDCs if high-consequence events might be associated with such inventories. Other issues associated with the LWR GDC or ARDC may be addressed by other parts of an application.

The issue will be considered further by the staff and industry and discussed again at Workshop #3. Aspects for consideration include cross-cutting GDC/ARDC; areas outside the TICAP scope such as releases during normal operation (GDC 60); and implications of GDC imposing requirements beyond those that might be established by LMP (e.g., GDC 17 and single failure).

J .Segala At the end of the workshop the staff noted the dates for the remaining workshop and the target date of early June 2021 for the NRC staff to provide a complete set of comments on the industrys draft TICAP guidance document and industrys target of late July for providing a revision to the document. The staff noted that the list provided in Enclosure 2 are the high-level issues associated with industrys draft guidance document. The staff informed industry that it was also developing comments embedded within the draft document that did not rise to a level to be discussed during the workshops. The staff and industry also discussed the need for a future meeting focused on resolution of Topics 6 and 9, as discussed above, and agreed to coordinate on scheduling of this during the June 2021 timeframe.

Enclosure:

1. Attendance List

2. List of Topics of Discussion for TICAP Workshops

ML21158A223 NRC-001 OFFICE NRR/DANU/UARP/PM NRR/DANU/UARP/BC NRR/DANU/UARP/PM NAME EOesterle JSegala EOesterle DATE 6/7/2021 6/8/2021 6/8/2021 May 26, 2021, Public Meeting to Discuss Technology Inclusive Content of Application Project Attendance List*

NAME AFFILIATION NAME AFFILIATION Nathan Sanfilippo NRC/NRR/DANU Amir Afzali Southern Company Martin Stutzke NRC/NRR/DANU Jason Redd Southern Nuclear William Reckley NRC/NRR/DANU/UARP Brandon Chisholm Southern Company John Segala NRC/NRR/DANU/UARP Mike Tschiltz NEI Prosanta NRC/NRR/DANU/UARP Cyril Draffin US Nuclear Industry Chowdhury Council Maryam Khan NRC/NRR/DANU/UARP George Flanagan Oak Ridge National Lab Eric Oesterle NRC/NRR/DANU/UARP Ed Wallace GNBC Associates Arlon Costa NRC/NRR/DANU/UARP Steven Nesbit LMNT Consulting Juan Uribe NRC/NRR/DANU/UARP Frank Akstulewicz A to Z Reactor Consulting Services Amy Cubbage NRC/NRR/DANU/UARP Steve Vaughn X-energy Joe Sebrosky NRC/NRR/DANU/UARP Travis X-Energy Chapman Nan Valliere NRC/NRR/DANU/UARP Jim Kinsey Idaho National Laboratory (INL)

Jordan Hoellman NRC/NRR/DANU/UARP Tom King INL Stephen Philpott NRC/NRR/DANU/UARP Christopher Chwasz INL Alex Chereskin NRC/NRR/DANU/UART Tom Hicks INL Margaret OBanion NRC/NRR/DANU/UARP Ricardo Davis-Zapata GE Power Jan Mazza NRC/NRR/DANU/UARL Dennis Henneke GE Power Mallecia Sutton NRC/NRR/DANU/UARL George GE Power Wadkins Hanh Phan NRC/NRR/DANU/UART Archana Not Available (NA)

Manoharan Alexandra Siwy NRC/NRR/DANU/UARL Farshid Shahrokhi NA Michelle Hayes NRC/NRR/DANU/UART Lance Sterling NA Michelle Hart NRC/NRR/DANU/UART Bill Fowler NA Timothy Lupold NRC/NRR/DANU/UART Michael Mayfield NA Ian Jung NRC/NRR/DANU/UART Alan Levin NA Chris Van Wert NRC/NRR/DANU/UART Tom Braudt NA Boyce Travis NRC/NRR/DANU/UART Karl Fleming NA Tim Drzewiecki NRC/NRR/DANU/UART Jana Bergman NA Carolyn Lauron NRC/NRR/DNRL/NLRB Rob Burg NA Eric Bowman NRC/COMM/CS Barton Landon Pate NA Yuan Cheng NRR/NRC/DEX/EXHB Amanda Spalding NA Julie Ezell NRC/OGC Narasimha Kadambi NA Marcia Carpentier NRC/OGC Stephen Burns NA David Heeszel NRC/NRR/DEX/EXHB Parthasarathy NA Chandran Barbara Hayes NRC/NRR/DEX/EXHB Steven Pope NA Baindur Satyen NA Alan Jelalian NA Kamal Manoly NRC/NRR/DEX Jason Andrus NA Andrew Zach EPW Anthony Schoedel NA Enclosure 1

NAME AFFILIATION NAME AFFILIATION Caroline Cochran Oklo Rachel Turney NA Chantal Morin NA

• Attendance list based on Microsoft Teams Participant list. List does not include 5 unidentified individuals that connected via phone.

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List of Topics of Discussion for Technology Inclusive Content of Application Project Workshops Workshop 1 Red font indicates Cell color denotes Workshop 2 Workshop #3 updates on workshop in which issue Workshop 3 topics discussed in prior was first discussed workshops Issue

1. Topic Priority Comments Disposition 1 The construction permit (CP) guidance Hi For Sections 1.2, 1.3, 1.4, 2.4 there is no CP guidance. For Workshop #2 contained in the twostep Licensing Section 2.3, simplified and/or qualitative analyses should be section is not sufficiently detailed to available to support reasonable assurance findings Comment 4: TICAP reiterated its intention to ensure consistent implementation. (examples are provided in Appendix C of NRCs Construction take another look at how/if TICAP guidance Permit White Paper found at ADAMS Accession No. needs to address 50.43(e) (see Issue 7 from ML21043A339) Workshop 1).

Chapter 3 - Use of term preliminary assessments. What Comment 5: TICAP will expand guidance on does that mean? Should reference bounding assumptions R&D plans. Currently this is in Section 2.3, but it and conservative modeling to account for the uncertainty in could be expanded to SSC system descriptions final design details. Should reference discussion of the in Chapters 6 and 7.

major SSCs of the facility that are intended to mitigate the radiological consequences of a design basis accident (DBA). Comment 7: TICAP will revise Section 2.1.1 to clarify that the PRA assumptions should be For Chapter 4, the staff would like to understand better the available for NRC audit but are not required to use of term preliminary description of the integrated plant be provided in the PSAR.

performance.

TICAP will consider adding CP guidance for For Chapter 6, guidance for first of a kind (FOAK) structures, Section 2.4 as well, recognizing that it will systems and components (SSCs) does not appear to be necessarily be general.

sufficiently detailed to ensure consistent implementation.

TICAP will consider NRC expectations in the The CP guidance should consider including a description of draft TICAP Guidance Document Reg Guide for the research and development (R&D) plans supporting the incorporation into the Guidance Document.

design. This includes PRA documentation at the CP stage.

The minimum level of detail to support a CP application should be considered for discussion. The CP white paper TICAP will look at early site permit (ESP) provides thoughts regarding minimum level of detail. guidance in Reg Guide 1.206 for potential application to CP guidance, but noted that the The nonlight water reactor probabilistic risk assessment inherent differences between ESPs and CPs may (NLWR PRA) standard (ASME/ANS RAS142021) contains Enclosure 2

Issue

1. Topic Priority Comments Disposition numerous supporting requirements to document the limit applicability. NRC also noted the Clinch assumptions made in lieu of detailed design information. River ESP as a possible resource.

Will these assumptions be identified in the preliminary safety analysis report (PSAR) or will they be provided in the detailed PRA information (which is only available to the staff via an onsite audit)? This comment is related to Issue

1. 8 below.

The staff expects that the TICAP guidance document will be used to support nearterm nonLWR CP applications.

Discussions of how the TICAP guidance document might be used along with preapplication discussions to aid the near term reviews could be a topic of a workshop. Such an approach could potentially be used to develop nearterm guidance with revised updated guidance being issued at a later date. The revised guidance could be based on lessons learned from the initial construction permit reviews.

2 Source term guidance might need to be Med The source term discussion should require the attenuation Workshop #1 expanded. mechanisms be described. These are just as important in limiting radionuclide release as is fuel performance. TICAP to clarify in guidance that attenuation mechanisms are to be described.

Source terms should be detailed for each licensing basis event (LBE), but no confirmatory analyses is done to ensure inclusion of all source terms.

3 The guidance in several areas is too Workshop #1 general to ensure consistent and adequate implementation, such as the TICAP acknowledges that some guidance can be use of terms like relevant made more specific but there are limitations on phenomena, initial operating how specific for technology inclusive guidance.

conditions, and identify treatments.

Additional examples in this area are NRC to provide additional examples as part of provided in items 3a through 3d below. written comments.

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Issue

1. Topic Priority Comments Disposition 3a The guidance should be more specific For modular nuclear power reactor design; describe and TICAP believes multiple modules are addressed in specifying initial plant parameters, analyze the possible operating configurations of the reactor in LBE descriptions (Chapter 3) and interface settings of protection system functions, modules with common systems, interface requirements, requirements and system interactions are meteorological assumptions, and system interactions. addressed in system descriptions (Chapters 6 uncertainty assumptions, and and 7). However, TICAP will review the current characteristics of fission product wording to see if enhancements are warranted.

releases assumed in the LBE analysis.

3b The guidance regarding the defense in Section 4.2 (DID) states that the scope and content of the TICAP discussed desire to focus SAR content on depth (DID) content should be final safety analysis report (FSAR) are focused on presenting results rather than process.

expanded to address the areas results, not details of the process. It goes on to say that the discussed in the staffs April 2020 topics to be addressed in the evaluation of DID are for NRC to provide specific recommendations annotated outline in Chapter 7 (see: background and there is no requirement to address each where additional DID content is desired in the ADAMS Accession No. ML20107J565) topic in the FSAR. Why isnt discussion of the evaluation SAR, along with the rationale.

which were derived from NEI 1804 topics important enough to be placed in the FSAR? This provides the technical basis for the DID adequacy NRC provided additional comments on DID on determination. Other sections (4.2.1, 5.4) make similar May 17, 2021. Response to those several statements with no basis. comments follow; note that these issues were crosscutting for Topics 3b, 10, 12.

NEI 1804 (Section 5.9.3) states that the adequacy of DID is confirmed when the actions and decisions (listed in 5.9.3) are completed by the Integrated DecisionMaking Process (IDP). There is hardly any mention of the IDP in the TICAP guidance, yet NEI 1804 emphasizes it.

Section 5.4 (SafetyRelated SSCs) states in the introduction that in identifying safetyrelated SSCs, the SSCs not selected as safetyrelated constitute one element of Plant Capability DID. However, the introduction goes on to say that these DID SSCs are not design basis information. Why aren't DID SSCs in the design basis? What is the basis for excluding the information used to select the safetyrelated SSCs from the SAR?"

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated TICAP guidance document Section 4.2 addresses defensein General Comment Response:

May 17, 2021 depth (DID). It is unclear from the guidance that an Multiple comments have overlapping themes adequate level of detail would be included in the SAR and content. TICAP reconciliation of the basic regarding the evaluation of DID. comments required to extract individual points for inclusion in TICAP guidance updates.

TICAP plans to update the DID guidance with the following common understanding:

o TICAP DID content will focus on the final results of the Integrated Review Process.

o Supporting records will contain additional details of the IDP deliberations.

o DID baseline content, i.e. that necessary to set the framework for future DID change evaluations should be provided in the SAR.

o DID topic discussion outlined in NEI 1804 will be parsed among multiple TICAP chapters, i.e, 3, 4, 5, 6, 7 and 8 as appropriate to support the specific topic discussions in those chapters.

The revised DID guidance will also reflect the dispositions associated with Comments 17 below.

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated Comment 1 See General Comment Response above May 17, 2021 Add the following to Section 4.2: Baseline Evaluation of Defense in Depth This section should describe the baseline level of defense in depth provided by the proposed facility. This baseline is established when the recurring evaluation of plant capability and programmatic capability associated with design and PRA update cycles no longer identifies risk significant vulnerabilities where potential compensatory actions can make a practical, significant improvement to the LBE risk profiles or risksignificant reductions in the level of uncertainty in characterizing the LBE frequencies and consequences. This baseline DID evaluation and its outcome are to be documented in sufficient detail to assure that future changes to physical, functional, operational, or programmatic features of the facility can be effectively evaluated for their potential for reduction of DID before proceeding.

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated Comment 2 Response 2.1 See General Comment Response May 17, 2021 Section 4.2.1 describes SAR content guidance for plant above.

capability DID evaluations. Suggest the following changes to Section 4.2.1: Response 2.2 - re minimization The parties agreed that minimization was not The purpose of this section is to provide a description of the objective.

the SSCs and the layers of defense they represent in the overall achievement of an acceptable level of DID. The TICAP agreed to review the chain of evidence application should describe how the design meets the required across the chapters to make sure the guidelines for plant capability attributes provided in NEI 18 DID Attributes in NEI 1804 are captured in the 04 Table 52 [Guidelines for Establishing the Adequacy of various guidance sections.

Overall Plant Capability DefenseinDepth]. Separate discussions of plant capabilities that are relied upon to meet these plant capability attributes should be provided in this section. For example, describe how the design minimizes the frequency of challenges to safetyrelated SSCs including controlling abnormal operation, detecting failures and preventing design basis accidents.

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated Comment 3 Response 3.1 See General Comment Response May 17, 2021 Modify TICAP text in Section 4.2.1.2 as follows: above.

This section should describe how the design addresses Response 3.2 - TICAP clarified that single each qualitative guideline in NEI 1804 Table 52 for each feature evaluation would be summarized in LBE and describe any departures from the stated criteria. Chapter 4. TICAP also emphasized that the SAR The applicant should provide a summary identification of content for DID adequacy focused on results the layers of defense for each risksignificant LBE and and should not have to document negative describe the extent of independence between different LBE findings of the review that had no impact on layers of defense. The applicant should describe for each the design or operational programs. Such risksignificant LBE how the design does not have an over negative findings should be available in reliance on a single design feature, barrier, or operational supporting records of the IDP.

feature relied upon to meet quantitative objectives. The criteria used to decide whether or not an over reliance Response 3.3 - TICAP clarified its position on exists should be provided. The application should describe the term overreliance as used in the TICAP how the process identifies the potential for common cause guidance and NEI 1804 and the adequacy of failures and how those vulnerabilities were eliminated. NEI 1804 to deal with this qualitative objective.

Describe how the design provides an appropriate balance between event prevention and mitigation in the layers of Response 3.4 - TICAP identified the PRA defense for risksignificant LBEs. The criteria used to decide standard and resulting records as the source of whether or not there is an appropriate balance between information for common cause evaluations.

prevention and mitigation should be provided. The necessary content is part of the Plant Capability evaluation of LBEs.

Response 3.5 - TICAP clarified that its approach to preventionmitigation balance is contained in the examination of layers of defense. The need for additional guidance on layers of defense in Chapter 3 and 4 will be reviewed.

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated Comment 4 Response 4.1 see related discussion in May 17, 2021 Add new text to section 4.2.1.2 as follows: Response 3.5.

For SSCs that perform prevention and mitigation functions Response 4.2 Performance targets are being for risksignificant LBEs, describe the set of requirements addressed under Topic 9.

related to the performance, reliability, and availability of the SSC functions that are relied upon to ensure the Response 4.3 - TICAP clarified that special accomplishment of their tasks, as defined by the PRA or treatments are discussed in Chapters 5, 6 and 7.

deterministic analysis. This section should also describe the capability of those SSCs relied upon for DID. This should include how that capability is ensured through testing, maintenance, inspection and performance monitoring. If this information is provided in other sections it need not be repeated here.

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated Comment 5 Response 5.1 See General Comment Response May 17, 2021 Section 4.2.2 describes SAR content guidance for above.

programmatic DID evaluations. Suggest modifying the text in Section 4.2.2 as follows: Response 5.2 TICAP clarified that the discussion on uncertainties related to Programmatic DID should be used to address uncertainties evaluating plant capability uncertainties, not when evaluating plant capability DID as well as uncertainties programmatic uncertainties. The TICAP in programmatic measures. It should provide the basis for guidance in Chapter 4 is being revised and will defining special treatment requirements to ensure there is contain additional guidance on the topic of reasonable assurance that the predicted performance of uncertainties.

SSCs and programmatic measures can be achieved throughout the life of the plant. The application should Response 5.3 NRC clarified that the comment describe how the design incorporates the programmatic on unknowns was referring to the DID capability attributes provided in NEI 1804 Table 56 to attributes in NEI 1804 Table 56.

provide adequate assurance that the risk, reliability, and performance targets will be met and maintained throughout the life of the plant with adequate consideration of sources of significant uncertainties. This description should support the discussion of special treatment programs selected for safetysignificant SSCs described in Chapters 6 and 7. Special treatments described in NEI 1804 Table 57 should be considered, although the application does not need to address items that are not applicable. The application should describe how uncertainty in programmatic DID is addressed and how additional measures are in place to address unknowns.

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Issue

1. Topic Priority Comments Disposition 3.b Additional NRC DID Comments dated Comment 6 Response 6.1 TICAP noted that Chapter 4 will May 17, 2021 Add a requirement to summarize the integrated decision focus on the integrated DID results not making process (IDP) which NEI 1804 emphasizes (in contained in other chapters.

Section 5.6) as responsible for making the deliberate, affirmative decision that DID adequacy has been achieved. Response 6.2 reaffirmed that the DID SAR Suggest the following be added to the TICAP guidance content is focused on results for the DID document: baseline and that the results will be distributed across multiple chapters.

The application should summarize how the IDP process was applied in evaluating the overall adequacy of DID. The description should address how each of the decision guidelines listed in NEI 1804, Section 5.9.3, was evaluated and the basis for an affirmative response. The criteria used in making the decisions (e.g., risk margins are sufficient, prevention/mitigation balance is sufficient, etc.) should be provided. If quantitative measures were used as part of the criteria, they should be provided. A description of how the results of the IDP process are documented and available for future DID decisionmaking and operations support should also be provided.

3.b Additional NRC DID Comments dated Comment 7 Response 7.1 TICAP observed that the general May 17, 2021 Add the following to the end of section 4.2: topic of SAR change control was common to Evaluation and Incorporation of Changes to Defense in other portions of the licensing. TICAP Depth confirmed that the discussion of baseline DID information in NEI 1804 was in recognition of The change control process should be described addressing this need.

how the baseline DID evaluation will be reevaluated, based on proposed changes, to determine which programmatic or The parties agreed that the change control plant capability attributes have been affected for each layer topic is broader than TICAP.

of defense. Changes that impact the definition and Further discussion of change control outside of evaluation of LBEs, safety classification of SSCs, or risk TICAP are anticipated.

significance of LBEs or SSCs must be assessed. This section should also describe how any changes to the baseline DID evaluation will be documented and implemented.

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Issue

1. Topic Priority Comments Disposition 3c In addressing the special treatments Describe safety related (SR) SSC reliability targets and TICAP will enhance the linkages between special the guidance should specify that the performance requirements used as input to the PRA for treatments in Chapters 6 and 7 and the application address the special SSCs that were used to develop the selection of special programs in Chapter 8.

treatment requirements from NEI 18 treatment requirements (i.e., programmatic actions used to 04, Table 41, on a casebycase basis maintain performance within the design reliability targets). TICAP stated that the SAR content for the LMP and in the context of the SSC functions based affirmative safety case should focus of in the prevention and mitigation of Guidance should point to NEI 1804 Table 41 and have the the special treatments that were selected applicable LBEs. applicant address the items in that list: through the LMP process, vs. documenting why (from NEI 1804, Table 41, as applicable) special treatments were not selected.

i. Equipment qualification ii. Seismic qualification iii. Materials qualification iv. Preservice and riskinformed inservice inspections

v. Preop and startup testing requirements vi. Surveillance testing requirements 3d Similarly, guidance discussion of The programmatic actions used to maintain performance TICAP will revisit the linkages between special "optional" programs should instead within the design reliability targets should include a treatments and programs (see 3c).

make a clearer tie between identified description of how actual SSC reliability is determined and special treatments and the programs compared against the design reliability target (e.g., as part NRC clarified that optional refers to whether or that implement those treatments of the Maintenance Rule program). not the special treatment invoking the program was selected.

4 The guidance references the modular Hi An example discussion from the staffs safety evaluation Workshop #1 high temperature gas cooled reactor found at ADAMS Accession No. ML052780497 is as follows:

preliminary safety information The PSID references were for the purposes of document (PSID) as guidance but does Some events were not defined explicitly enough to guidance documentation only; the safety not reference the staffs safety quantify properly. Commonmode and commoncause evaluation is therefore not relevant to the evaluation report on that PSID which events were not present explicitly in the models. Human guidance.

identified gaps in necessary content. failure events were too vaguely described to determine Discuss whether actual guidance that is whether they were assumed to occur before the event TICAP will revisit the PSID examples to update referenced should be placed in the initiation or afterMost restrictive in tracing the results of them or, if necessary, replace them with TICAP TICAP guidance document instead of the PRA was the fact that there is no list of basic events that examples.

referencing the document includes the occurrence probability associated with each event. TICAP will endeavor to include the examples directly in the guidance rather than referencing them.

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Issue

1. Topic Priority Comments Disposition 5 The document describes a move away Hi The TICAP guidance does not require the NRC regulations Workshop #2 from compliancebased applications to applicable to the design be identified or discussed. Isnt the a more performancebased approach. purpose of the FSAR to demonstrate compliance with the TICAP will revisit wording of compliance It's not clear from these statements applicable regulations? based in the Guidance Document (p. 4 under whether applicants will be expected to Scope) to ensure there is no unintended describe how they comply with the LMP primarily addresses the 50.34 requirements to identify implication that a TICAP application is not regulations that are associated with the events, plant response to those events, and associated required to comply with regulations.

performancebased scope and safety margins. This provides an alternative to the LWR outcomes of the affirmative safety case based regulations that directly connect to this part of 50.34 approach. regulations is an expectation (50.46 requirements for ECCS, for example). Is this the for application content. basic population of regulations industry is referring to in its proposed change from compliancebased?

Does the content of this TICAP guidance align with the NRCs regulatory applicability assessments in NRC Staff Draft White Paper Analysis of Applicability of NRC Regulations for NonLight Water Reactors, as discussed in recent nonLWR stakeholder meetings?

Potentially another way to consider the affirmative safety case approach is stated in RG 1.233 as safety evaluations may demonstrate compliance with or justify exemptions from specific NRC regulations and identify where design specific regulatory controls are warranted. An application will need to address the results from the safety case in terms of where current regulations do not contribute to safety (exemptions) or where current regulations are lacking (additional requirements). Whereas the safety case should focus on satisfying subject functions, it would be useful to agree on a format for compliance/exemption discussions, be they embedded, in a table, or other format.

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6 The guidance for inclusion of principal Hi This statement is not correct For plants that use the NEI Workshop #2 design criteria (PDC) may be 1804 methodology, the PDC that flows from the LMP incomplete, since only "LMP outcomes" methodology and are needed to support the LMPbased NRC believes the TICAP approach to are addressed, and other topics from safety case are based on the RSFs and the Required establishing the RFDC as the PDC is too narrow.

Part 50 App. A (like Monitoring Fuel & Functional Design Criteria (RFDC). RFDCs are used to Waste Storage) are not clearly included supplement or modify ARDCs in developing PDCs. RG TICAP does not believe the intent of NEI 1804 for consideration 1.232 should be referenced since there are other PDCs that was to impose deterministic PDC on a risk are not tied to RFDCs (e.g., ARDCs 1 through 4). informed, performancebased process.

Section 5.3 seems to imply that PDCs are only for DBEs and The issue will be considered further by TICAP DBAs. What design criteria are applied to address BDBEs? and NRC and discussed again at Workshop #3.

Aspects for consideration include crosscutting Section 5.3: For plants that use the NEI 1804 GDC/ARDC; areas outside TICAP scope such as methodology, the PDC that flows from the LMP releases during normal operation (GDC 60); and methodology and are needed to support the LMPbased implications of GDC imposing requirements safety case are based on the RSFs and the Required beyond those that might be established by LMP Functional Design Criteria (RFDC) (e.g., GDC 17 and single failure).

Section 5.6: Thus, the PSAR content for Chapter 5 should A future conversation will be held between include functional decomposition of FSFs to RSFs, a TICAP and NRC/INL staff regarding the preliminary set of RFDC/PDC with performancebased definition of Principal Design Criteria (PDC) in criteria Appendix A of 10 CFR Part 50 and the most efficient way for TICAP PDC to comply with From NEI 1804 4.1 Task 7: RFDCs are defined to capture existing regulations while not losing the designspecific criteria that may be used to supplement or advantages provided by an RIPB approach. One modify the applicable General Design Criteria or Advanced specific aspect to discuss is the amount of Reactor Design Criteria in the formulation of Principal specificity (i.e., how detailed a PDC must be)

Design Criteria. that is appropriate and/or required for the set of PDC (e.g., are derived requirements The TICAP methodologies are trying to adapt the PDC necessary to be identified as PDC?).

concept to the affirmative safety case approach and equate the PDC to those associated with RSFs. In that approach, considering nonreactor sources could have associated RSFs and PDCs if highconsequence events might be associated with such inventories. Other issues associated with the LWR GDC or ARDC may be addressed by other parts of an application.

13

Issue

1. Topic Priority Comments Disposition 7 The guidance includes a requirement to Hi 50.34(e)(1)(i): The performance of each safety feature of Workshop #1 include testing/qualification plans for the design has been demonstrated through either analysis, firstofa kind (FOAK) safetyrelated appropriate test programs, experience, or a combination NRC believes that 50.43(e) testing is inherently SSCs for CP applications. This thereof fundamental to the safety case and should requirement is reflected in 50.43(e), therefore be included under TICAP guidance.

and also applies to the other types of 50.43(e) requires applicants to provide the collection of applications covered in the guidance analyses, tests, OE, etc. necessary to assure the expected TICAP believes that the NEI 1804 methodology (COL, DC, OL) but is not discussed in the performance of safety features. Does this safety does not encompass the 50.43(e) regulation, guidance for those other application feature requirement apply to both SR and NSRST SSCs? but that results of 50.43(e) testing would likely types. appear in the technical justifications supporting Chapters 6 & 7 of the SAR in an application would reflect the safety case (e.g., benchmark data for the required capabilities of SR and NSRST SSCs. Where computer codes used to analyze DBAs).

would the proof of those capabilities be provided to address 50.43(e)? (Its noted that this topic is called out for FOAK SR This is an example of disagreement on the SSCs reflected in twostep CP applications, but the scope of the TICAP guidance. Additional clarity document seems to be silent on the issue for DC, COL, ML). with respect to scope and NRC expectations will be needed.

Nevertheless, TICAP will take another look at whether and, if so, how the 50.43(e) testing could be addressed by TICAP.

TICAP will modify its guidance to reflect that it is not just CPs but DCs and COLs that may invoke FOAK testing as special treatments.

Disposition is as discussed on the slides for workshop #3 modification of guidance for Chapters 2, 6, and 7 as indicated. If the NRC desires a specific section in the SAR covering a 50.43(e) test program, NRC will develop guidance for that section. TICAP believes the appropriate location for such a section would be SAR Chapter 2.

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Issue

1. Topic Priority Comments Disposition 8 The level of detail in the SAR, Hi Discuss that if the staff relies on something they review as Workshop #1 supporting information placed on the part of an audit to make their safety finding, that the docket, and information that is specifics of that item then need to be elevated into the TICAP understands that NRC citing an item in an available for audit were identified as FSAR or an IBR document? audit report does not put that in the licensing potential items for further discussion basis.

during the TICAP tabletop exercises. Make clear that reports that are IBRd are part of the During the TICAP tabletop exercises it licensing basis and change control process. TICAP confirmed that IBR in the SAR makes the was also noted that there is a information in the IBR reference part of the distinction between items incorporated Section 1.2 states that the site attributes relevant to the licensing basis and subject to the NRC change by reference (IBR) into the SAR and safety case are in Chapter 2. There is no site information in control processes.

references to the SAR. IBRd item is Chapter 2.

considered to be part of the licensing TICAP explained that the reference to site basis for the plant. There is no mention of fuel qualification. information in Chapter 2 is based on the understanding that ARCAP will address site RG 1.233 provided clarifications in certain areas. Does the information there.

TICAP guidance document intend to include these?

The treatment of fuel qualification will be discussed in ARCAP/TICAP discussions in Workshop #3.

15

Issue

1. Topic Priority Comments Disposition 9 During the discussion of nonsafety Hi SAR should describe reliability targets and performance Workshop #1 related with special treatment (NSRST) requirements used as input to the PRA for SSCs that were structures, systems, and components used to develop the selection of special treatment NRC believes the reliability targets should be (SSC) SAR content, the NRC staff raised requirements (i.e., programmatic actions used to maintain provided in the SAR. NRC notes that NEI 1804 a question regarding where the performance within the design reliability targets). stated the reliability and capability targets reliability information for these SSCs for SR and NSRST SSCs, and special treatment would be located (e.g., PRA or SAR) and Section 6.2 states that the SSC reliability and availability requirements for SR and NSRST SSCs define what this information might entail. The information will not be in the FSAR. This is design basis safetysignificant aspects of the descriptions of NRC staff believes further discussion on information that is needed for determining the SSCs that should be included in safety analysis this topic would be beneficial. effectiveness of the maintenance program, the reliability reports. NRC further believes the information TICAP stated that the applicant is assurance program and the ISI/IST programs. What is the should be in the SAR.

responsible for ensuring it is addressing basis for excluding it from the FSAR?

Reg Guide 1.233 including clarifications TICAP believes the targets should be owner and limitations therein. TICAP does not Section 7.1 defines NSRST special treatment requirements, controlled information, not maintained in the see much daylight between NEI 1804 no tie to performance targets SAR. TICAP acknowledges the NEI 1804 and Reg Guide 1.233. statement but believes TICAP guidance Section 8 plant programs has special treatments for SR specifically for the SAR can supersede NEI 1804 SSCs and NSRST SSCs may involve programs relied upon to statements on SAR content. TICAP provide reasonable assurance acknowledges that one in the draft guidance (introduction to Chapter 6) is not aligned with The introduction to Chapter 6 says This further detail the TICAP position, but that statement was

[Chapter 6] includes SRDC, reliability and capability mistakenly included in the April 15, 2021 draft performancebased targets, and special treatment guidance.

requirements to provide sufficient confidence that the performancebased targets intended in the design will be TICAP and NRC will consider the issue further achieved in the construction of the plant and maintained and revisit it at Workshop 3.

throughout the licensed plant life. This statement appears to support that these targets should be in SAR. TICAP acknowledges the need to be consistent with the guidance in NEI 1804. The NRC and It may be acceptable to point to where the information the TICAP Team plan to have a focused follow resides (e.g., reliability assurance program) versus putting up meeting on the topic, probably in the mid actual reliability assumptions in the SAR. June time frame.

16

Issue

1. Topic Priority Comments Disposition 10 The SAR content should focus on Hi The description should address each of the decision Related to item 8 presenting the results of implementing guidelines described in Section 5.9.3 of NEI 1804, including Workshop #1 the LMP process. For discussion the basis for concluding the guideline has been met. For purposes, it may be beneficial to those guidelines where a quantitative measure can be See disposition of additional NRC DID discuss what type of documentation provided, those measures used in the decisionmaking comments under Issue 3b.

may exist from implementing the LMP should be provided.

process by the applicant, including narrative on the iterations in the process, and the deliberations and Numerous places in 1804 detail documentation needs for decisions of the integrated bases or decisions. The TICAP report should highlight what decisionmaking process (IDP) and is documented in a TR, and what is in the SAR whether this documentation may be something that is audited by the NRC staff.

17

Issue

1. Topic Priority Comments Disposition 11 NEI 1804 (Section 3.2.2 - Task 6) states Hi There is Note on Page 51 that reads Note: The Workshop #2 that, where possible, external events development of the DBEHLs is addressed by ARCAP and are to be analyzed in the PRA but, in summarized in SAR Chapter 2. TICAP will consider additional guidance in some cases, may be selected and Section 6.1.1 to clarify the deterministic treated deterministically. There is no Section 6.1.1 states that the design only needs to protect selection of DBEHLs.

discussion in the TICAP guidance against external hazards with a frequency greater than 1 E document about how to select and 4/yr. Does this exclude BDBE external hazards from TICAP will consider additional guidance in treat external events selected using a consideration? Chapter 3 about incorporation of external deterministic approach. Accordingly, hazards into the LBE determination process.

the VTR report did not address this Section 2.2 includes external events in the PRA. How are topic. deterministically selected external events addressed in the TICAP will consider typical information in PRA? Chapter 3 of LWR SARs and determine if the level of detail in Section 6.1.1 should be Additionally, incorporation of external hazards into the LBE enhanced.

determination process lacks basis and detail in 1804 and the TICAP document.

Proposed 10 CFR 53.510(a) sets the design basis external hazard levels (DBHELs) at 1E5/plantyear. RG 1.208 (seismic) establishes the sitespecific ground motion response spectrum (GMRS) such that the frequency of significant inelastic deformation (FOSID) is 1E5/y. RG 1.76 (tornados) and RG 1.221 (hurricanes) set DBHELs at 1E7/y.

12 The discussion of DID in Section 4.2 of a Hi Section 4.2 it states Note that the above information Related to one of the subbullets in item 3 -

SAR developed using the TICAP [topics listed in NEI 1804 Table 51] is provided for Workshop #1 guidance is a good candidate for background, and there is no requirement to address each discussion as part of the upcoming topic in the SAR material. How does an applicant address See disposition of additional NRC DID workshops with the NRC/INL staff. this? comments under Issue 3b.

13 Based on internal discussion with the HI Note that the guidance more accurately reflects the NEI 18 Workshop #2 staff - believe a discussion of principal 04 PDC development than was performed by eVinci.

design criteria guidance embedded in No items identified for disposition specific to draft industry document is appropriate this issue. PDC issues are being covered under in accordance with eVinci TICAP Issue 6.

tabletop exercise comments 18

Issue

1. Topic Priority Comments Disposition 14 Currently the scope of the TICAP Hi The guidance document needs to also address scopeof ESP, Workshop #1 guidance document covers only COLs. DC and ML applications. Regarding ESPs, the staff believes The scope of the TICAP guidance an applicant using the TICAP guidance might leverage TICAP to consider changes to clarify that document should be expanded to information from an ESP in developing their application alternative licensing paths twostep licensing include applicability for OL applicants (e.g., informing the DBEHL determination). guidance is applicable to the CP, not to the OL, under Part 50 and the supplemental and that the baseline TICAP guidance is guidance for the twostep licensing The level of detail and design maturity for an OL application applicable to the OL.

process should be limited to just CP is expected to be the same as for a COL applicant. By applicants. incorporating this comment the guidance for CP applicants NRC to provide details of examples of TICAP can be made more clear and specific - currently the entries guidance departing from NEI positions as stated under the Two Part Licensing Process are confusing, in NEI comments on the draft construction inaccurate in some places, and lack specificity in others. permit Interim Staff Guidance.

On 4/2/2021, NEI submitted comments (ML21092A115) on the draft CP ISG. One comment stated that the NRC should not be requiring that the design and analysis for a CPA be at the same level of completion as for a COLA. This differs from the TICAP statement.

15 For supplemental guidance for Design Med Similar to #14, all licenses should be covered Workshop #1 Certifications there are no entries for several sections. Need to clarify intent TICAP clarified that no entry for DC means no for these no entries (I.e., guidance adjustments to the baseline guidance for DCs.

provided for COLs applies) or if additional discussion is intended 16 For supplemental guidance for Design DCs should address DID as part of the design including Workshop #1 Certifications, it appears that perhaps identification of needed special treatments. The only only limited DID adequacy assessments difference from a COL is the development of the TICAP will revise guidance as needed to reflect might be able to be performed due to operational program description which would not be DC adjustments due to the fact that DC does the fact that the expectations on expected in a DC. not address operating plantspecific topics.

operational program descriptions for DC applicants is not equivalent to COL applicants. May also have some impact on identification of special treatments.

17 The TICAP guidance document refers to Med The staff notes that this issue could be considered as Part Workshop #3 licensing basis, however, there is a 53 language is developed for Subpart H and I.

19

Issue

1. Topic Priority Comments Disposition definition of current licensing basis TICAP did not take issue with the basic contained in 10 CFR 54.3 which was definition of current licensing basis in necessitated by license renewal. 10CFR54.3. TICAP does not plan to include a Should a reference to that definition be licensing basis definition or reference in the included in the guidance or should that TICAP Guidance.

definition be revisited and redefined for the purposes of use of the LMP [Note: TICAP indicated that it would take a approach or for inclusion in Part 53 for further look at the use of that definition more that matter. Question for discussion is broadly and its basis would have any whether or not the definition needs to unintended consequences if the definition was be modified for the purposes of this used outside the scope of Part 54. This review guidance document or other advanced was targeted for completion by midJune.]

reactor guidance documents?

18 There should be alignment on the Need to align on the proposal that Chapter 1 is not licensing Workshop #3 proposal to not include licensing basis basis information w/o having a clear definition of licensing information in Chapter 1. The purpose, basis for LMPbased SARs or even what the change process TICAP to review chapter 1 and the use of I think, is to also exclude Chapter 1 for would entail. licensing Basis terminology to see how it can the change process and reduce future clarify that Chapter 1 is not somehow excluded regulatory burden. However, our from the 50.59 change process since it is a part current concept of the change process of the FSAR. This should be done in the context is 10 CFR 50.59 and it is not clear as to of our review of Issue 17 which is also focused what the change process under Part 53 on licensing basis and the definition in might be. 10CFR54.3.

19 Several sections refer to tables in the Hi It would be more useful to include the tables and useful Workshop #1 LMP Tabletop Exercise Report or to guidance referred to within the TICAP guidance document.

useful guidance in the MHTGR PSID See Disposition of Issue #4 document. (ERO) 20

Issue

1. Topic Priority Comments Disposition 20 Around Workshop #3, the staff is Med Workshop #3 considering discussion of a draft TICAP RG and an ARCAP roadmap ISG to start The NRC will consider the TICAP comments as the discussion on how industrys provided on the Workshop #3 TICAP slides as it guidance is envisioned to fit within continues to develop its ARCAP ISG and TICAP TICAP and the staffs initial thinking on Reg Guide.

where industrys TICAP guidance is envisioned to be supplemented (e.g.,

fuel qualification, ASME Section III Division 5, design review guide for I&C) 21 The term safety case is not currently Hi TICAP page 4 states The term safety case is a collection of No items identified for disposition specific to used in NRC licensing processes. statements that, if confirmed to be true by supporting this issue.

technical information, establishes reasonable assurance of adequate protection for operation of the nuclear power plant described in the application. TICAP Figure 1 on page 6 shows the relation between TICAP and an advanced reactor license application; specifically, the affirmative safety case addressed by TICAP is necessary, but not sufficient, to establish reasonable assurance of adequate protection. Need alignment on what a safety is and, equally important, what it is not.

21

Issue

1. Topic Priority Comments Disposition 22 The staff has provided industry with a Hi Workshop #3 list of NRC observations from the TICAP tabletop exercises. To date, industrys TICAP has not identified additional items for feedback on these observations has discussion which have not already been covered been limited to the first two TICAP by other Issues.

tabletop exercise observations. The NRC staff would be interested in industrys feedback on the NRC observations for the last two TICAP tabletop exercises (i.e., the eVinci microreactor, and the molten chloride reactor experiment (MCRE)). In particular, the NRC staff would be interested in whether industry identifies potential workshop items from eVinci and MCRE TICAP tabletop exercises that are not captured in the items identified above.

22

Issue

1. Topic Priority Comments Disposition 23 The NRC staff finds that additional Hi In Section 2.1.1, the overview of PRA needs additional No items identified for disposition specific to information and clarity on PRA is clarity regarding peer review, the use of technically this issue.

needed in the TICAP guidance. adequate PRA, the level of details, and so on. In addition, PRA for construction permit applications needs discussion The NRC may provide specific written with the NRC staff since there is ongoing discussions on the comments related to this issue.

subject as part of the NRC staffs ongoing development of guidance on construction permit. It is noted that the NRC recently updated CP guidance regarding nonLWR designs and PRAs; In Section 2.1.2, the summary of key PRA results should the CP angle is addressed under Issue #1.

include other information such as key assumptions, the results and insights from importance, sensitivity, and uncertainty analyses, and so on.

Although other Chapters (i.e., Chapter 3 and 4) include some of the PRA results or insights (such as risksignificant SSCs, human actions, etc.), it may be useful to have these key results under Section 2.1.2 to have the comprehensive PRA results in one place. Alternatively, a set of pointers (not at the Chapter level) at the individual topic areas may be included in Section 2.1.2.

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