ML21120A057

NRR E-mail Capture - Info and Action: Potential Issues to Be Discussed During Upcoming Technology Inclusive Content of Application Project (Ticap) Workshops

ML21120A057
Person / Time
Issue date:	04/29/2021
From:	Joseph Sebrosky NRC/NRR/DANU
To:	Afzali A Southern Company Services
References
Download: ML21120A057 (14)

Text

From: Sebrosky, Joseph Sent: Thursday, April 29, 2021 5:17 PM To: Afzali, Amir Cc: Jim C. Kinsey Jr; Christopher P. Chwasz; 'Tom King'; Thomas Hicks; Reckley, William; Uribe, Juan; Oesterle, Eric; Khan, Maryam; Van Wert, Christopher; Jung, Ian; Chowdhury, Prosanta; Travis, Boyce; Siwy, Alexandra; Segala, John; Stutzke, Martin; Cubbage, Amy; Michael Tschiltz; Chisholm, Brandon Michael; AUSTGEN, Kati; NICHOL, Marcus; Cyril Draffin; Steven Nesbit

Subject:

info and action: Potential Issues to be Discussed During Upcoming Technology Inclusive Content of Application Project (TICAP) Workshops Attachments: Potential List of Topics for Technology Inclusive Content of Application Project.docx Amir Afzali Southern Company Services Licensing and Policy Director - Next Generation Reactors Mr. Afzali, The purpose of this email is to transmit the attached document to you that provides the NRC staffs initial recommendations for potential items to be discussed during the technology inclusive content of application project (TICAP) publicly noticed workshops. The purpose of the workshops is to address issues related to the draft TICAP guidance document for Safety Analysis Report (SAR) content for an advanced reactor application based on the licensing modernization project (LMP) as endorsed by the NRC in Regulatory Guide 1.233. The draft TICAP guidance document is available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML21106A013.

As you know the first workshop is scheduled for May 11th, and the public notice for this meeting can be found at: https://www.nrc.gov/pmns/mtg?do=details&Code=20210516. The NRC staff looks forward to working with you and your staff in finalizing the agenda for the first workshop. A subsequent workshop has been tentatively scheduled for May 19th, and if needed a third workshop has been tentatively scheduled for May 26th.

Please let me know if you have any questions.

Sincerely, Joe Sebrosky Senior Project Manager Advanced Reactor Policy Branch Office of Nuclear Reactor Regulation 301-415-1132

Hearing Identifier: NRR_DRMA Email Number: 1162 Mail Envelope Properties (MN2PR09MB53853DE86459110F47FA499EF85F9)

Subject:

info and action: Potential Issues to be Discussed During Upcoming Technology Inclusive Content of Application Project (TICAP) Workshops Sent Date: 4/29/2021 5:16:39 PM Received Date: 4/29/2021 5:16:39 PM From: Sebrosky, Joseph Created By: Joseph.Sebrosky@nrc.gov Recipients:

"Jim C. Kinsey Jr" <jim.kinsey@inl.gov>

Tracking Status: None "Christopher P. Chwasz" <Christopher.Chwasz@inl.gov>

Tracking Status: None

"'Tom King'" <thomasking2993@gmail.com>

Tracking Status: None "Thomas Hicks" <hickste@earthlink.net>

Tracking Status: None "Reckley, William" <William.Reckley@nrc.gov>

Tracking Status: None "Uribe, Juan" <Juan.Uribe@nrc.gov>

Tracking Status: None "Oesterle, Eric" <Eric.Oesterle@nrc.gov>

Tracking Status: None "Khan, Maryam" <Maryam.Khan@nrc.gov>

Tracking Status: None "Van Wert, Christopher" <Christopher.VanWert@nrc.gov>

Tracking Status: None "Jung, Ian" <Ian.Jung@nrc.gov>

Tracking Status: None "Chowdhury, Prosanta" <Prosanta.Chowdhury@nrc.gov>

Tracking Status: None "Travis, Boyce" <Boyce.Travis@nrc.gov>

Tracking Status: None "Siwy, Alexandra" <alexandra.siwy@nrc.gov>

Tracking Status: None "Segala, John" <John.Segala@nrc.gov>

Tracking Status: None "Stutzke, Martin" <Martin.Stutzke@nrc.gov>

Tracking Status: None "Cubbage, Amy" <Amy.Cubbage@nrc.gov>

Tracking Status: None "Michael Tschiltz" <mdt@nei.org>

Tracking Status: None "Chisholm, Brandon Michael" <BMCHISHO@SOUTHERNCO.COM>

Tracking Status: None "AUSTGEN, Kati" <kra@nei.org>

Tracking Status: None "NICHOL, Marcus" <mrn@nei.org>

Tracking Status: None

"Cyril Draffin" <cyril.draffin@usnic.org>

Tracking Status: None "Steven Nesbit" <steve.nesbit@lmnt-consulting.com>

Tracking Status: None "Afzali, Amir" <AAFZALI@southernco.com>

Tracking Status: None Post Office: MN2PR09MB5385.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1416 4/29/2021 5:16:39 PM Potential List of Topics for Technology Inclusive Content of Application Project.docx 47408 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Potential List of Topics for Technology Inclusive Content of Application Project (TICAP) Workshops Updated 4/29/2021 General Notes:

The table identifies initial recommendations for potential items to be discussed during the technology inclusive content of application project (TICAP) publicly noticed workshops.

The purpose of the workshops is to address issues related to the draft TICAP guidance document for Safety Analysis Report (SAR) content for an advanced reactor application based on the licensing modernization project (LMP) as endorsed by the NRC in Regulatory Guide 1.233. The draft guidance document is available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML21106A013.

Example themes for the first two workshops are provided below with the third workshop agenda to be developed based on insights from the first two workshops.

Workshop 1

• Discussion of scope of the guidance document and associated level of detail expected in the SAR (numerous examples are provided in the table below) o The NRC believes working on example content during the workshop would aid in this discussion on this topic during the workshop. Without example content coming to a common understanding on level of detail could be difficult.

• What's included in the application (SAR + material incorporated by reference (IBR)) versus what information is available for audit, and how do NRC staff safety findings relate to the location and control of the information being reviewed.

Workshop 2

• The LMP approach primarily addresses the 50.34 requirements to identify events, plant response to those events, and associated safety margins. What about compliance with everything else in Parts 50 & 52?

• An expanded discussion of principle design criteria (PDC) and complimentary design criteria (CDC) development, with illustrative examples of each category.

Issue Topic Priority Comments Disposition 1 The construction permit (CP) guidance contained in Hi For Sections 1.2, 1.3, 1.4, 2.4 there is no CP guidance. For Section 2.3, Proposed for Workshop #1 the two-step Licensing section is not sufficiently simplified and/or qualitative analyses should be available to support discussion detailed to ensure consistent implementation. reasonable assurance findings (examples are provided in Appendix C of NRCs Construction Permit White Paper found at ADAMS Accession No. ML21043A339)

Chapter 3 - Use of term preliminary assessments. What does that mean? Should reference bounding assumptions and conservative modeling to account for the uncertainty in final design details. Should reference discussion of the major SSCs of the facility that are intended 1

to mitigate the radiological consequences of a design basis accident (DBA).

For Chapter 4, the staff would like to understand better the use of term preliminary description of the integrated plant performance.

For Chapter Chapter 6, guidance for first of a kind (FOAK) structures, systems and components (SSCs) does not appear to be sufficiently detailed to ensure consistent implementation.

The CP guidance should consider including a description of the research and development (R&D) plans supporting the design.

The minimum level of detail to support a CP application should be considered for discussion. The CP white paper provides thoughts regarding minimum level of detail.

The non-light water reactor probabilistic risk assessment (NLWR PRA) standard (ASME/ANS RA-S-1-4-2021) contains numerous supporting requirements to document the assumptions made in lieu of detailed design information. 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 #8 below.

The staff expects that the TICAP guidance document will be used to support near-term non-LWR 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 near-term 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 expanded. Med The source term discussion should require the attenuation mechanisms Workshop #1 be described. These are just as important in limiting radionuclide release as is fuel performance.

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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 general to Hi Workshop #1 - Suggest item 3 ensure consistent and adequate implementation, (and associated items 3a, 3b, such as the use of terms like relevant phenomena, 3c, and 3d be the subject of initial operating conditions, and identify Workshop #1.

treatments. Additional examples in this area are provided in items 3a through 3d below.

3a The guidance should be more specific in specifying For modular nuclear power reactor design; describe and analyze the initial plant parameters, settings of protection system possible operating configurations of the reactor modules with common functions, meteorological assumptions, uncertainty systems, interface requirements, and system interactions.

assumptions, and characteristics of fission product releases assumed in the LBE analysis.

3b The guidance regarding the defense in depth (DID) Section 4.2 (DID) states that the scope and content of the final safety content should be expanded to address the areas analysis report (FSAR) are focused on presenting results, not details of discussed in the staffs April 2020 annotated outline the process. It goes on to say that the topics to be addressed in the in Chapter 7 (see: ADAMS Accession No. evaluation of DID are for background and there is no requirement to ML20107J565) which were derived from NEI 18-04 address each topic in the FSAR. Why isnt discussion of the evaluation topics important enough to be placed in the FSAR? This provides the technical basis for the DID adequacy determination. Other sections (4.2.1, 5.4) make similar statements with no basis.

NEI 18-04 (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 Decision-Making Process (IDP). There is hardly any mention of the IDP in the TICAP guidance, yet NEI 18-04 emphasizes it.

Section 5.4 (Safety-Related SSCs) states in the introduction that in identifying safety-related SSCs, the SSCs not selected as safety-related 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 safety-related SSCs from the SAR?"

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3c In addressing the special treatments the guidance Describe safety related (SR) SSC reliability targets and performance should specify that the application address the requirements used as input to the PRA for SSCs that were used to special treatment requirements from NEI 18-04, develop the selection of special treatment requirements (i.e.,

Table 4-1, on a case-by-case basis and in the programmatic actions used to maintain performance within the design context of the SSC functions in the prevention and reliability targets).

mitigation of applicable LBEs. Guidance should point to NEI 18-04 Table 4-1 and have the applicant address the items in that list:

from NEI 18-04, Table 4-1, as applicable:

i. Equipment qualification ii. Seismic qualification iii. Materials qualification iv. Pre-service and risk-informed in-service inspections

v. Pre-op and startup testing requirements vi. Surveillance testing requirements 3d Similarly, guidance discussion of "optional" programs The programmatic actions used to maintain performance within the should instead make a clearer tie between identified design reliability targets should include a description of how actual SSC special treatments and the programs that implement reliability is determined and compared against the design reliability those treatments target (e.g., as part of the Maintenance Rule program).

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

information document (PSID) as guidance but does not reference the staffs safety evaluation report on Some events were not defined explicitly enough to quantify properly.

that PSID which identified gaps in necessary content. Common-mode and common-cause events were not present explicitly Discuss whether actual guidance that is referenced in the models. Human failure events were too vaguely described to should be placed in the TICAP guidance document determine whether they were assumed to occur before the event instead of referencing the document initiation or afterMost restrictive in tracing the results of the PRA was the fact that there is no list of basic events that includes the occurrence probability associated with each event.

5 The document describes a move away from Hi The TICAP guidance does not require the NRC regulations applicable to Workshop #2 compliance-based applications to a more the design be identified or discussed. Isnt the purpose of the FSAR to performance-based approach. It's not clear from demonstrate compliance with the applicable regulations?

these statements whether applicants will be expected to describe how they comply with the LMP primarily addresses the 50.34 requirements to identify events, regulations that are associated with the performance- plant response to those events, and associated safety margins. This based scope and outcomes of the affirmative safety provides an alternative to the LWR-based regulations that directly case approach. regulations is an expectation for connect to this part of 50.34 (50.46 requirements for ECCS, for application content.

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example). Is this the basic population of regulations industry is referring to in its proposed change from compliance-based?

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 Non-Light Water Reactors, as discussed in recent non-LWR 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.

6 The guidance for inclusion of principal design criteria Hi This statement is not correct For plants that use the NEI 18-04 Workshop #2 (PDC) may be incomplete, since only "LMP methodology, the PDC that flows from the LMP methodology and are outcomes" are addressed, and other topics from Part needed to support the LMP-based safety case are based on the RSFs 50 App. A (like Monitoring Fuel & Waste Storage) are and the Required Functional Design Criteria (RFDC). RFDCs are used not clearly included for consideration 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).

Section 5.3 seems to imply that PDCs are only for DBEs and DBAs.

What design criteria are applied to address BDBEs?

Section 5.3: 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)

Section 5.6: Thus, the PSAR content for Chapter 5 should include functional decomposition of FSFs to RSFs, a preliminary set of RFDC/PDC with performance-based criteria 5

From NEI 18-04 4.1 Task 7: 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.

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.

7 The guidance includes a requirement to include Hi 50.34(e)(1)(i): The performance of each safety feature of the design Potential Workshop #1 testing/qualification plans for first-of-a kind (FOAK) has been demonstrated through either analysis, appropriate test safety-related SSCs for CP applications. This programs, experience, or a combination thereof requirement is reflected in 50.43(e), and also applies to the other types of applications covered in the 50.43(e) requires applicants to provide the collection of analyses, tests, guidance (COL, DC, OL) but is not discussed in the OE, etc. necessary to assure the expected performance of safety guidance for those other application types. features. Does this safety feature requirement apply to both SR and NSRST SSCs?

Chapters 6 & 7 of the SAR in an application would reflect the required capabilities of SR and NSRST SSCs. Where would the proof of those capabilities be provided to address 50.43(e)? (Its noted that this topic is called out for FOAK SR SSCs reflected in two-step CP applications, but the document seems to be silent on the issue for DC, COL, ML).

8 The level of detail in the SAR, supporting information Hi Discuss that if the staff relies on something they review as part of an Note: items 8 through 13 placed on the docket, and information that is audit to make their safety finding, that the specifics of that item then identified by industry as possible available for audit were identified as potential items need to be elevated into the FSAR or an IBR document? topic based on feedback from for further discussion during the TICAP tabletop NRC observation of TICAP exercises. During the TICAP tabletop exercises it Make clear that reports that are IBRd are part of the licensing basis and tabletop exercises for X-energy was also noted that there is a distinction between change control process. and versatile test reactor items incorporated by reference (IBR) into the SAR and references to the SAR. IBRd item is considered Section 1.2 states that the site attributes relevant to the safety case are Workshop #1 to be part of the licensing basis for the plant. in Chapter 2. There is no site information in Chapter 2.

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There is no mention of fuel qualification.

RG 1.233 provided clarifications in certain areas. Does the TICAP guidance document intend to include these?

9 During the discussion of non-safety related with Hi SAR should describe reliability targets and performance requirements Workshop #1 special treatment (NSRST) structures, systems, and used as input to the PRA for SSCs that were used to develop the components (SSC) SAR content, the NRC staff selection of special treatment requirements (i.e., programmatic actions raised a question regarding where the reliability used to maintain performance within the design reliability targets).

information for these SSCs would be located (e.g.,

PRA or SAR) and what this information might entail. Section 6.2 states that the SSC reliability and availability information will The NRC staff believes further discussion on this not be in the FSAR. This is design basis information that is needed for topic would be beneficial. determining the effectiveness of the maintenance program, the reliability assurance program and the ISI/IST programs. What is the basis for excluding it from the FSAR?

Section 7.1 defines NSRST special treatment requirements, no tie to performance targets Section 8 plant programs has special treatments for SR SSCs and NSRST SSCs may involve programs relied upon to provide reasonable assurance The introduction to Chapter 6 says This further detail [Chapter 6]

includes SRDC, reliability and capability performance-based targets, and special treatment requirements to provide sufficient confidence that the performance-based targets intended in the design will be achieved in the construction of the plant and maintained throughout the licensed plant life. This statement appears to support that these targets should be in SAR.

It may be acceptable to point to where the information resides (e.g.,

reliability assurance program) versus putting actual reliability assumptions in the SAR.

10 The SAR content should focus on presenting the Hi The description should address each of the decision guidelines Related to item 8 results of implementing the LMP process. For described in Section 5.9.3 of NEI 18-04, including the basis for Workshop #1 discussion purposes, it may be beneficial to discuss concluding the guideline has been met. For those guidelines where a 7

what type of documentation may exist from quantitative measure can be provided, those measures used in the implementing the LMP process by the applicant, decision-making should be provided.

including narrative on the iterations in the process, and the deliberations and decisions of the integrated decisionmaking process (IDP) and whether this Numerous places in 18-04 detail documentation needs for bases or documentation may be something that is audited by decisions. The TICAP report should highlight what is documented in a the NRC staff. TR, and what is in the SAR 11 NEI 18-04 (Section 3.2.2 - Task 6) states that, where Hi There is Note on Page 51 that reads Note: The development of the Workshop #3 possible, external events are to be analyzed in the DBEHLs is addressed by ARCAP and summarized in SAR Chapter 2.

PRA but, in some cases, may be selected and treated deterministically. There is no discussion in Section 6.1.1 states that the design only needs to protect against the TICAP guidance document about how to select external hazards with a frequency greater than 1 E-4/yr. Does this and treat external events selected using a exclude BDBE external hazards from consideration?

deterministic approach. Accordingly, the VTR report did not address this topic. Section 2.2 includes external events in the PRA. How are deterministically selected external events addressed in the PRA?

Additionally, incorporation of external hazards into the LBE determination process lacks basis and detail in 18-04 and the TICAP document.

Proposed 10 CFR 53.510(a) sets the design basis external hazard levels (DBHELs) at 1E-5/plant-year. RG 1.208 (seismic) establishes the site-specific ground motion response spectrum (GMRS) such that the frequency of significant inelastic deformation (FOSID) is 1E-5/y. RG 1.76 (tornados) and RG 1.221 (hurricanes) set DBHELs at 1E-7/y.

12 The discussion of DID in Section 4.2 of a SAR Hi Section 4.2 it states Note that the above information [topics listed in Related to one of the sub-bullets developed using the TICAP guidance is a good NEI 18-04 Table 5-1] is provided for background, and there is no in item 3 - Workshop #1 candidate for discussion as part of the upcoming requirement to address each topic in the SAR material. How does an workshops with the NRC/INL staff. applicant address this?

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

embedded in draft industry document is appropriate in accordance with eVinci TICAP tabletop exercise comments 14 Currently the scope of the TICAP guidance Hi The guidance document needs to also address scopeof ESP, DC and Workshop #1 document covers only COLs. The scope of the ML applications. Regarding ESPs, the staff believes an applicant using 8

TICAP guidance document should be expanded to the TICAP guidance might leverage information from an ESP in include applicability for OL applicants under Part 50 developing their application (e.g., informing the DBEHL determination).

and the supplemental guidance for the two-step licensing process should be limited to just CP The level of detail and design maturity for an OL application is expected applicants. to be the same as for a COL applicant. By incorporating this comment the guidance for CP applicants can be made more clear and specific -

currently the entries under the Two Part Licensing Process are confusing, inaccurate in some places, and lack specificity in others.

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 Certifications Med Similar to #14, all licenses should be covered Workshop #1 there are no entries for several sections. Need to clarify intent for these no entries (I.e., guidance provided for COLs applies) or if additional discussion is intended 16 For supplemental guidance for Design Certifications, Med DCs should address DID as part of the design including identification of Workshop #1 it appears that perhaps only limited DID adequacy needed special treatments. The only difference from a COL is the assessments might be able to be performed due to development of the operational program description which would not be the fact that the expectations on operational program expected in a DC.

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 licensing Med The staff notes that this issue could be considered as Part 53 language Workshop #3?

basis, however, there is a definition of current is developed for Subpart H and I.

licensing basis contained in 10 CFR 54.3 which was necessitated by license renewal. Should a reference to that definition be included in the guidance or should that definition be revisited and redefined for the purposes of use of the LMP approach or for inclusion in Part 53 for that matter. Question for discussion is whether or not the definition needs to be modified for the purposes of this guidance 9

document or other advanced reactor guidance documents?

18 There should be alignment on the proposal to not Hi Need to align on the proposal that Chapter 1 is not licensing basis Workshop #3?

include licensing basis information in Chapter 1. The information w/o having a clear definition of licensing basis for LMP-purpose, I think, is to also exclude Chapter 1 for the based SARs or even what the change process would entail.

change process and reduce future regulatory burden.

However, our current concept of the change process is 10 CFR 50.59 and it is not clear as to what the change process under Part 53 might be.

19 Several sections refer to tables in the LMP Tabletop Hi It would be more useful to include the tables and useful guidance Workshop #1 Exercise Report or to useful guidance in the MHTGR referred to within the TICAP guidance document, PSID document. (ERO) 20 Around Workshop #3, the staff is considering Med Workshop #3?

discussion of a draft TICAP RG and an ARCAP roadmap ISG to start the discussion on how industrys guidance is envisioned to fit within TICAP and the staffs initial thinking on 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 used in NRC Hi TICAP page 4 states The term safety case is a collection of statements Workshop #2 licensing processes. that, if confirmed to be true by supporting 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.

22 The staff has provided industry with a list of NRC Hi Workshop depends on insights observations from the TICAP tabletop exercises. To from industry date, industrys feedback on these observations has been limited to the first two TICAP 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 10

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.

23 The NRC staff finds that additional information and Hi In Section 2.1.1, the overview of PRA needs additional clarity regarding clarity on PRA is needed in the TICAP guidance. peer review, the use of technically adequate PRA, the level of details, and so on. In addition, PRA for construction permit applications needs discussion with the NRC staff since there is ongoing discussions on the subject as part of the NRC staffs ongoing development of guidance on construction permit.

In Section 2.1.2, the summary of key PRA results should 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 risk-significant 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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