ML22013B183

Preliminary List of Exceptions, Clarifications, and Additions to NEI 21-07, Revision 0-B, Technology Inclusive Guidance for Non-Light Water Reactors: Safety Analysis Report for Applicants Utilizing the NEI 18-04 Methodology

ML22013B183
Person / Time
Issue date:	01/13/2022
From:	Joseph Sebrosky NRC/NRR/DANU/UARP
To:
sebrosky
References
Download: ML22013B183 (11)

Text

Preliminary List of Exceptions, Clarifications, and Additions to NEI 21-07, Revision 0-B, Technology Inclusive Guidance for Non-Light Water Reactors: Safety Analysis Report for Applicants Utilizing the NEI 18-04 Methodology (ADAMS Accession No. ML21343A292)

January 13, 2022 Note: 1) This document provides an update to a document that provided NRC staffs preliminary list of exceptions, clarifications, and additions, that was developed based on NEI 21-07, Revision 0 (see: ML21274A032)

2) The following color coding applies to the disposition column found in this table:

Issue resolved based on NEI 21-07, Revision 0-B proposed change Issue resolved based on forthcoming staff change to TICAP DG Issue resolved based on TICAP DG December 2, 2021 document Issue not resolved - further discussion needed NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID A.2 Background Page 3 (last paragraph) - Further discussion is needed in either NEI 21-07, Revision 1, or Clarification No change proposed Resolved - based on TICAP the TICAP draft RG white paper to clarify that in addition to making a safety case, an DG change found in applicant should also make a licensing case that focuses on compliance with applicable December 2, 2021 version regulations and includes any exemptions, as necessary.

A.3a Supplemental information Page 3 Scope. The staff will continue to reference in its TICAP RG the guidance that is Clarification and Addition No change proposed Resolved - based on NRC affecting first 8 chapters of the relevant to the first 8 chapters of the SAR (e.g., siting, fuel qualification, instrumentation and action to ensure all SAR outside the scope of control Design Review Guide, ASME Section III Division 5). See supplemental information supplemental information has Industry TICAP guidance found in July 8, 2021 version of TICAP RG draft white paper been added to the draft RG https://www.nrc.gov/docs/ML2119/ML21190A014.pdf A.3b Scope Page 4 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification NEI 21-07 revised to Resolved RG white paper to clarify that that an affirmative safety case should include normal address normal operation.

operation and that applicants should also make a licensing case with respect to compliance with regulations and include exemptions, as necessary. That is, the applicant must make the case for and claim compliance with or exemptions from specific regulations. The NRC will not just review the safety case and derive from it those regulations that are met in order to makes its findings.

B.2 SAR Outline Page 7 (bottom) - Further discussion is needed in either NEI 21-07, Revision 1, or the Clarification Addressed via A.3b Resolved TICAP draft RG white paper to clarify that an affirmative safety case should include normal operation as well as LBEs.

All Italicized discussion contained Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white Clarification Various Resolved based on NRC in NEI 21-07 is not considered paper clarifying the meaning of the use of the regular text and text in italics throughout the position to be included in to be guidance. SAR content guidance in Section C of NEI 21-07. Examples of text that the staff believes TICAP DG that all discussion should be in regular font vice in italics can be found in the attachment to this document. in NEI 21-07 is guidance and This attachment contains background information on specific examples of where the staff not requirements, therefore believed the use of italicized text was inappropriate and whether industry made changes to NRC considers the italicized remove the subject italicized text in NEI 21-07, Revision 0-B. The attachment is provided as text to be guidance and is not 1

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID background. As discussed in the last column in this row the staff plans to address this issue limited to background and as one item in the forthcoming revision to the TICAP DG. context only.

B.5 Scope and Two-Step Licensing Pages 4 and 10 - Clarification of several items should be made: (1) the requirement under Clarification and Addition Item (1) addressed via A.3b. Resolved based on NEI 21-07 (CP/OL) 50.34(a)(4) for demonstration of an affirmative safety case that includes normal operation Item (2) not addressed revision and TICAP RG draft reflecting that the Licensing Modernization Project (LMP) does not address normal change found in December 2, operation; (2) a licensing case also needs to be made by the applicant with respect to claims 2021 document of compliance with or requests for exemption from regulations; and (3) the COL application scope includes Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) whereas the CP/OL scope does not.

Clarification proposed that the LMP-based safety case shifts from compliance with prescriptive regulatory requirements to an approach that focuses on identification and performance of fundamental safety functions to address and satisfy associated regulatory requirements and provide reasonable assurance of adequate protection of public health and safety.

B.6 Design Certification Page 11 - Further discussion is needed in either NEI 21-07, Revision 1, or in the TICAP Clarification and Addition NEI 21-07 revised Resolved draft RG white paper to clarify that the SAR content developed through use of LMP is similar in scope only to the Tier 2 information required for a DC application. Guidance for Tier 1 information, including ITAAC, required for a DC application is neither contemplated by NEI 18-04 nor discussed in the TICAP guidance document.

Also included a proposed change to page 11 (last paragraph) to reference Tier 2 Information 1b Licensing Basis Information Page 15 - Clarify what language in Chapter 1 of a SAR will be included and maintained as Clarification NEI 21-07 revised Resolved part of the licensing basis, and what parts of the regulation those parts seek to fulfill.

1.1.2 Intended Use of the Reactor Page 16 - The NEI proposed text does not seem to fully address 10 CFR 50.34(a)(1)(ii)(A) Addition NEI 21-07 revised Resolved based on NRC staff regarding use of the reactor. Further discussion is needed in either NEI 21-07, Revision 1, action to include discussion in or the TICAP draft RG white paper to address the radioactive materials inventory portion of TICAP DG that describes the the regulation. need to address radioactive materials inventory in the SAR.

1.3.3 Defense in Depth Page 20 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification and Addition NEI 21-07 revised Resolved RG white paper to clarify that DID adequacy is based on 3 elements; plant capability DID, programmatic DID, and risk-informed, performance-based (RIPB) DID. Applicants should address RIPB DID also and cite key examples for this DID element 2a Pre-licensing engagement Page 20 - The highlighted sentence gives the incorrect perception that pre-licensing Clarification NEI 21-07 revised Resolved based on NEI 21-07 interactions affect the level of detail that should be provided within the docketed license revision and NRC action to application and related submittals (e.g., topical reports) add a discussion to the TICAP DG that broadly recognized that separate licensing documents (e.g.,

topical reports) submitted during pre-licensing submittals as well as during application review may reduce the information that needs to be included in the SAR if IBRd. White papers, 2

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID etc., not reviewed and approved by NRC will not reduce info in SAR. IBRd info is part of SAR.

2.1 PRA discussion to be included Page 21- The fourth and fifth sentences in the first paragraph of Section 2.1 provide Clarification NEI 21-07 revised Resolved in the SAR guidance and should therefore be in regular text. In order to reflect the Commissions affirmation in SRM-SECY-2015-002 regarding the need for probabilistic risk assessment (PRA) information for CP/OL applications for new reactors, they should be modified to read, The PRA information included in the SAR should be at a summary level only as described below. It should include a description of the design-specific or plant-specific PRA, as appropriate, and its results.

2.1.1a Conformance (with any Page 21 and 22 - Trial-use RG 1.247 to endorse the std is under development. NRC staff Clarification NEI 21-07 revised Resolved based on NEI 21-07 deviations) with the advanced positions in RG 1.247, once issued, should be addressed along with the Std. revision and NRC action to non-LWR PRA standard, reference RG 1.247 in trial ASME/ANS RA-S-1.4-2021 NEI 20-09, Revision 1, has been submitted to the NRC for endorsement. Revision 1 should use form in supplemental be cited instead of Revision 0. information in TICAP DG.

NEI 20-09, Rev. 0 PRA peer review 2.1.1b Discussion of PRA information Page 22 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft Clarification and Addition NEI 21-07 revised Resolved to be included in the SAR RG white paper to cover the level of detail for the PRA information to be included in the SAR as follows: This section should describe PRA assumptions, the identification of PRA-based insights, and an overview of the results and insights from importance, sensitivity, and uncertainty analyses. A pointer should be provided if the information is described in other Chapters (e.g., Chapter 3). Detailed information used in the PRA will not be included in the SAR but will be available for NRC audit.

2.1.1c Discussion of PRA info in SAR Page 22 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft Clarification and Addition NEI 21-07 revised Resolved

- Two-step licensing (CP RG with paper to clarify the basis for omitting peer review for PRA for a CP application as application) follows (italics are used to set off the clarification - final text should be in regular font): To be clear, consistent with the baseline for this guidance, to the extent that an applicant does not request any design finality as part of its CP application, no PRA peer review should be required at the CP application stage.

2.1.2 Summary of Key PRA Results Page 23 - The last bullet in this section states that SAR Chapters 6 and 7 are to address Clarification and Addition NEI 21-07 revised Resolved reliability and capability targets for SR and NSRST SSCs. Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper to address SR and NSRST human actions.

3.3 Anticipated operational Page 30 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification No change proposed Not resolved. Needs further occurrences (AOOs) - RG white paper to clarify that non-DBA LBEs as analyzed in the PRA should be discussion clarification of discussion of summarized in the SAR.

AOOs in the SAR 3.3.1 AOOs - key information Page 31 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification and Exception No change proposed Not resolved. Needs further regarding AOOs should be RG white paper to clarify that a description of the models, site characteristics, and discussion.

captured in the SAR supporting data associated with the calculation of the mechanistic source terms and radiological consequences (to the extent such information is not provided in Section 2.2) should be included in the discussion of AOOs with a release in Section 3.3.1 of the SAR.

The text stating that this information is only in plant records should be removed from NEI 21-07, Revision 1 or addressed by an exception in the TICAP draft RG white paper. The word additional is suggested as a modifier to the information that should be provided for any 3

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID AOO with a release in the sentence preceding the bulleted list to clarify that it is in addition to the narrative that should be provided for each AOO as listed in the same section.

The exception to the statement regarding omission of the information and retention in plant records is appropriate because the safety case for the reactor is tied to appropriately identifying licensing basis events, including Anticipated Operational Occurrences (AOOs),

Design Basis Events (DBEs), Design Basis Accidents (DBAs), and Beyond Design Basis Events (BDBEs). This type of information should be captured in the SAR to ensure that changes to the plant are appropriately assessed under the applicable change process (e.g.,

10 CFR 50.59) reflecting their status as methods of evaluation used in establishing the design bases or in safety analyses.

3.4.1 Design Basis Events (DBEs) - Page 32 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification and Exception No change proposed Not resolved. Needs further key information regarding RG white paper to document the need for a description of the models, site characteristics, discussion.

DBEs should be captured in and supporting data associated with the calculation of the mechanistic source terms and the SAR radiological consequences for DBEs with a release (to the extent such information is not provided in Section 2.2). The text stating that this information is only in plant records should be removed from NEI 21-07, Revision 1 or addressed by an exception in the TICAP draft RG white paper. The word additional is suggested as a modifier to the information that should be provided for the most limiting DBE that was used to map into each DBA to clarify that it is in addition to the narrative that should be provided for each DBE as listed in the same section.

The exception to the statement regarding omission of the information and retention in plant records appropriate because the safety case for the reactor is tied to appropriately identifying licensing basis events, including Anticipated Operational Occurrences (AOOs),

Design Basis Events (DBEs), Design Basis Accidents (DBAs), and Beyond Design Basis Events (BDBEs). This type of information should be captured in the SAR to ensure that changes to the plant are appropriately assessed under the applicable change process (e.g.,

10 CFR 50.59) reflecting their status as methods of evaluation used in establishing the design bases or in safety analyses.

3.5.1 Beyond Design Basis Events Page 33 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white Clarification and Exception No change proposed Not resolved. Needs further (BDBEs) - key information paper to document the need for a description of the models, site characteristics, and discussion.

regarding BDBEs should be supporting data associated with the calculation of the mechanistic source terms and captured in the SAR radiological consequences for BDBEs with a release (to the extent such information is not provided in Section 2.2). The text stating that this information is only in plant records should be removed from NEI 21-07, Revision 1 or addressed by an exception in the TICAP draft RG white paper. The word additional is suggested as a modifier to the information that should be provided for information provided for BDBEs with a release to clarify that it is in addition to the narrative that should be provided for each BDBE.

The exception to the statement regarding omission of the information and retention in plant records appropriate because the safety case for the reactor is tied to appropriately identifying licensing basis events, including Anticipated Operational Occurrences (AOOs),

Design Basis Events (DBEs), Design Basis Accidents (DBAs), and Beyond Design Basis Events (BDBEs). This type of information should be captured in the SAR to ensure that changes to the plant are appropriately assessed under the applicable change process (e.g.,

4

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID 10 CFR 50.59) reflecting their status as methods of evaluation used in establishing the design bases or in safety analyses.

4.1 Discussion of overall plant risk Page 36 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Addition No change proposed Not resolved. Need further information found in the SAR RG white paper to document the need for a discussion of the following items where different discussion.

from the analysis performed under Chapter 3:

• The site parameters (e.g., meteorology, off-site population distribution, EAB size) used in the analysis,

• Assumptions on location of individual members of the public,

• Source of dose (cloud shine, inhalation, ground shine),

• The analysis method used,

• Key assumptions (e.g., emergency preparedness measures, source terms, timing and duration of release, credit for medical treatment, early and latent fatality risk coefficients) used in the analysis,

• Modes of operation (full power, low power & shutdown, refueling) considered in the analysis,

• How multiple units on the site were considered,

• Uncertainty/sensitivity analysis performed.

4.2.1 Guidance for DID evaluation Page 38- Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification No change proposed Resolved RG white paper to document that For SSCs that are relied upon to perform DID prevention and mitigation functions for risk-significant LBEs, and where not described elsewhere in the SAR, this section should describe the set of requirements related to the performance, reliability, and availability of the SSC functions that are relied upon to ensure the accomplishment of their tasks, as defined by the PRA or deterministic analysis. This description should include how that capability is ensured through testing, maintenance, inspection and performance monitoring.

4.2.1.4 Prevention-Mitigation Balance Page 41 - ADAMS ML numbers or hyperlinks to referenced documents and reports should Clarification Deferred. Can be added later.

be added to promote efficient user interface with this guidance document.

4.2.2b Guidance for programmatic Page 41 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification No change proposed Resolved via withdrawal of DID added RG white paper to document that The applicant should provide the justification for where comment by NRC.

the design does not incorporate the programmatic capability attributes provided in NEI 18-04 Table 5-6. This text should be regular font.

4.2.2.2 Human Factors Considerations Page 42, Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft Addition No change proposed Resolved based on staff

- SR SSC performance RG white paper to state that an applicant should include the description of programs to action to add reference in Monitoring assure human performance for risk-significant functions should address human factors TICAP DG to ARCAP Chapter considerations such as operating experience review, safety function review, human action 11 ISG to ensure holistic task analysis, human system interface design, procedures, training, and verification and approach to HFE program validation (V&V), human performance monitoring (where not described in Chapter 6).

4.2.2.3 Human Factors Considerations Page 43, Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft Addition No change proposed Resolved based on staff

- NSRST SSC performance RG white paper to state that an applicant should include the description of programs to action to add reference in monitoring assure human performance for safety-significant functions should address human factors TICAP DG to ARCAP Chapter considerations such as operating experience review, safety function review, human action 11 ISG to ensure holistic task analysis, human system interface design, procedures, training and V&V, human approach to HFE program.

performance monitoring (where not described in Chapter 7).

4.2.3b Integrated defense in depth Page 43 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Addition NEI 21-07 revised. Some Resolved based on staff discussion in the SAR RG white paper to document that an applicant should address the following to describe how discussion at the 12/14/21 action to add discussion in the integrated DID analysis meets the standards in NEI 18-04: The applicant should public meeting indicated that TICAP DG that describes the 5

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID summarize how the integrated DID process was applied in evaluating the overall adequacy TICAP may reassess their need to also include a of DID. The description should address how each of the decision guidelines listed in NEI 18- position. summary of DID assessment, 04, Section 5.9.3, was evaluated and the basis for an affirmative response. The criteria used criteria, results, and the basis in making the decisions (e.g., risk margins are sufficient, prevention/mitigation balance is for the results, not just a sufficient, etc.) should be provided. If quantitative measures were used as part of the reference to the process criteria, they should be provided. A description of how the results of the integrated DID process are documented and available for future DID decision-making and operations support should also be provided.

4.2.3c Added guidance to include a Page 43 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification and Addition NEI 21-07 revised Resolved based on staff description of the change RG white paper to document that an applicant should include a discussion of the change action to include reference in process to defense in depth process associated with defense in depth analysis described in Section 4.2.3 of the NEI TICAP DG supplemental discussion found in the SAR guidance document: The change control process should be described addressing how the information to ongoing efforts baseline DID evaluation will be re-evaluated, based on proposed changes, to determine to develop change control which programmatic or plant capability attributes have been affected for each layer of process that will include defense. Changes that impact the definition and evaluation of LBEs, safety classification of assessment of DID SSCs, or risk significance of LBEs or SSCs should be assessed.

5.3 Principal Design Criteria (PDC) Page 45 and 46- considering whether following proposed addition is appropriate related to Note - staff still developing TBD Awaiting TICAP response to PDC guidance: These LMP derived requirements may be considered together with generic position and path forward NRCs PDC position.

applicable Advanced Reactor Design Criteria (ARDC) in formulating the principal design regarding PDC guidance. It criteria for the license application. When considering the use of generic ARDC for this is unclear at this point as to purpose, the LMP methodology does not include the application of the Single Failure whether an exception, Criterion (SFC) that is included in the ARDC language. In the LMP approach to formulating clarification or addition (or a design requirements for SSCs, reliability and capability targets are used to inform the combination of these) will be selection of special treatment requirements. This obviates the need to applying the SFC. included in the staff TICAP Hence when ARDCs are considered in developing the principal design criteria, the SFC RG language should be removed.

Last sentence, third paragraph proposed edits to be more consistent with stated NRC positions:

However, the General Design Criteria and Advanced Reactor Design Criteria are intended to provide guidance in establishing the principal design criteria for non-LWR designs.

Fourth paragraph proposed edits to be more consistent with stated NRC positions.

Proposed revised paragraph 5.5.1 Non-Safety-Related SSCs Page 48 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Addition TBD Awaiting TICAP response to performing risk significant RG white paper to document that information similar to that found in Tables 5-1 and 5-2 for NRCs PDC position.

functions discussion in the safety-related SSCs should be provided for non-safety-related SSCs performing a risk-SAR significant function.

5.6a Complimentary Design Criteria Page 50 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft Clarification and Addition TBD Awaiting TICAP response to (CDC) discussion in the SAR RG white paper regarding CDC information that should be provided in the SAR, similar to NRCs PDC position.

the comments provided in an August 13, 2021, email that was discussed during an August 17, 2021, public meeting (see: ML21225A565)

This could include (a) the CDC are considered part of the affirmative safety case, since they specify safety criteria, (b) when they are defined at the functional level, they are considered equivalent to PDC and (c) when they are defined at the PRA Safety Function level, they are 6

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID considered subparts of a higher level PDC. In addition, the TICAP Guidance Document text should provide examples of both types of defined CDC.

The staff notes that the expectations regarding discussion of the CDC information in the SAR could be influenced by the outcome of the staffs position regarding PDC.

5.6b CDC discussion in the SAR Page 50 - Language should be added to clarify that NSRST SSCs may be included within Clarification TBD Awaiting TICAP response to the PDC rather than being limited to inclusion in the CDC. NRCs PDC position.

5.6c CDC discussion in SAR Page 50 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification TBD Awaiting TICAP response to RG white paper to clarify that the importance and contribution of engineering criteria for the NRCs PDC position.

design will be considered under 10 CFR 50.35(a), as necessary, in the finding of reasonable assurance regardless of whether the NSRST SSCs are addressed by CDC. The focus is on the engineering criteria for the design rather than inclusion of SSCs as part of CDC or PDC.

It is clear from the LMP process that NSRST SSCs are necessary for either PRA Safety Functions or DID. Inclusion of CDC may also bridge the gap between the NRC's expectation for an affirmative safety case and an LMP-based affirmative safety case which does not include normal operations (see comment in earlier Section A.3) 6.1.1b Design Basis Hazard Level Page 52 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Clarification No change proposed Resolved based on staff discussion in the SAR RG white paper to clarify that the SAR Should include discussion regarding the calculation action to include clarification methodology for DBHLS loads on the SSCs in TICAP DG that discussion of non-PRA evaluation Calculation methodology has traditionally been part of the licensing basis. For example, methodology needs to be where the methodology for combining loads is either ABSUM (absolute summation) or included in SAR.

SRSS (square root of sum of the squares) can make a big difference for the design loads on SSCs. Also, there is a 50.59 question that specifically focuses on evaluation methodology.

Not sure if this question will carry over to Part 53 but Part 50 and Part 52 applicants will need to consider it.

6.1.1c Design Basis Hazard Level Page 52 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft Clarification and Addition NEI 21-07 revised Resolved (DBHL) discussion in the SAR RG white paper to clarify that an applicant should summarize the basis for the DBHLs in the SAR.

6.1.1d Editorial correction to Table 6-1 Page 53 - verify that the table title and the second column heading should exclude the term Clarification NEI 21-07 revised Resolved external.

6.3/7.2 First-of-a-kind (FOAK) SR Page 58 and 61 - Text suggests incomplete V&V tests can be covered under special Clarification and Addition NEI 21-07 revised Resolved SSCs and NSRST SSCs treatment at the submittal of a license application. Staff suggests an addition / revision to the text to include the timing of the NRC SER and the possibility of license conditions, consistent with 10 CFR 50.43(e).

6.4.1a Human Factors Considerations Page 58 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Addition NEI 21-07 revised Resolved

- SR SSCs RG white paper to clarify that where human actions perform required safety functions, the description of controls and displays should address human factors considerations such as operating experience review, safety function review, human action task analysis, human system interface design, and V&V.

7.3.1a Human Factors Considerations Page 62 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft Addition NEI 21-07 revised Resolved

- NSRST SSCs RG white paper to clarify that where human actions perform PRA safety functions, the description of controls and displays should address human factors considerations such as operating experience review, safety function review, human action task analysis, human system interface design, and V&V.

6.4.1b and Human Reliability and Pages 58 and 62 - These sections list the design aspects of the various SR and NSRST Addition NEI 21-07 revised Resolved 7.3.1b Capability SSCs, including human actions. Further discussion is needed in either NEI 21-07, Revision 7

NEI 21-07 Topic Discussion Type TICAP Response Disposition Section Number ID 1, or the TICAP draft RG white paper to clarify that the applicant should describe the measures to be taken to ensure that the human actions meet their reliability and capability targets assumed in the PRA. For the reliability and capability of equipment, these measures are called Special Treatment.

Appendix B Example LBE Descriptions The staff does not plan to endorse Appendix B Example Descriptions of NEI 21-07 Clarification No change proposed Not resolved. NRC has because the agency does not endorse examples provided in guidance documents due to action to consider whether the need for technical review and approval. statements can be added to the reference to the Appendix associated with endorsement of the appendix Acronyms Editorials 8

Background Information Regarding Use of Italicized Text Note: The information in this table is provided for ease of reference and contains: a description of the original issue, whether NEI 21-07 Revision 0-B made changes, and whether the staff would have found these changes acceptable. As discussed in the master table above the staff intends to make a change in the TICAP DG that would address the use of italicized text in general.

NEI 21-07 Section Topic Issue Type TICAP Response NRC Feedback Number 1a Guidance in Introduction Page 15 - The fourth, fifth, and sixth paragraphs of this section should be regular text since Addresses level of SAR detail No change proposed. 1.a - Use regular font on the Section should be regular they provide instructions for the applicant regarding information to be included, formatting, expected. 6th paragraph.

font. and level of detail.

2b Discussion of topical Page 20 - topical reports approved by the NRC during pre-application engagement Change made to NEI 21- Resolved reports activities should be incorporated by reference into the SAR and not simply be listed as 07 (Pg 21).

general references. Applicants should specifically identify documents IBRd into the SAR.

The staff also believes the sentence should be in regular text.

3 Guidance regarding Page 26 - The third paragraph should be in regular font because it provides guidance Addresses scope of LBE No change proposed. Make 3rd para regular font.

licensing basis events regarding LBEs. analyses.

should be regular font 3.6 DBA guidance should be Page 34 - The fourth paragraph in this section should be regular font because it provides Addresses scope of DBA SAR No change proposed. Make 4th para regular font.

regular font. guidance regarding the documentation of conservative deterministic DBA analyses that is content generally modeled after accident analysis descriptions found in Chapter 15 of SARs for current LWRs.

4.2a Guidance regarding DID Page 37- the final sentence in the first paragraph of Section 4.2 should be in regular font Change made Resolved should be regular font. because it provides guidance.

4.2b Defense in depth Page 37 - the second paragraph of Section 4.2 and the bulleted list immediately below it No change proposed for Page 37 - 2nd paragraph and discussion and should be in regular font and not in italics since it provides guidance. first and third item. bulleted list in 4.2b should be clarification that some of Change proposed for regular font.

the guidance should be in second item (i.e. 6th bullet regular text The sixth bullet of this list should be modified to read, Evaluation of single features that comment 6th bullet issue resolved are risk significant to assure no overdependence on that feature ."

First sentence after bullets -

The first sentence of the paragraph following these bullets in Section 4.2 should be revised should be modified and regular to state: Note that the information responsive to this bulleted list should be provided in font.

either this chapter or in Chapters 3, 5, 6, 7, and 8.

4.2.1 DID Plant Capability Page 38 - portion of 2nd paragraph should be in regular font 2nd sentence describes scope No change proposed 2nd sentence should be regular Summary of evaluation font.

4.2.1.2 DID guidance should be Page 39 - The first paragraph in this section should be regular font because it provides No change proposed Resolved regular font. guidance regarding the DID evaluation.

4.2.2a Defense in Depth Page 41 and 42, the second paragraph in Section 4.2.2, which starts with Programmatic All but 1st sentence Resolved Summary discussion in DID should be used ... should be in regular font and not in italics since it provides changed.

the SAR guidance.

Attachment

NEI 21-07 Section Topic Issue Type TICAP Response NRC Feedback Number 4.2.3b Integrated defense in Page 43, the following text should be in regular font and not in italics since it provides No change in font. One Font should be changed.

depth discussion in the guidance: The baseline DID evaluation results in the SAR reflect the finalization of all DID sentence added in regular Requires the basis for SAR adequacy evaluations. The evaluation in this section determines that incremental font requiring the DID conclusions on DID adequacy evaluations of DID outlined in NEI 18-04, Section 5.9.3, for plant capability are collectively decision process be (from the IDP) be documented complete, programmatic actions are appropriate to sustain identified safety significant summarized in the SAR.

performance requirements and residual risks are very low.

4.2.2.1 Evaluation of Significant Page 42 - Further discussion in needed in either NEI 21-07, Revision 1 or the TICAP draft No change proposed Resolved since subsequent Uncertainties RG white paper to document that The consideration of uncertainties may also identify regular text covers the issue.

some sources of uncertainty that may be safety significant and lead to specific actions for DID purposes. A summary of the sources of significant uncertainty should be describe in the SAR. The details of these analyses should be documented in plant records. This text should be in regular font 4.2.3 Integrated DID evaluation Page 43 - the following text should be in regular font and not in italics since it provides No change proposed Same comment as 4.2.3b guidance: The baseline DID evaluation results in the SAR reflect the finalization of all DID above adequacy evaluations. The evaluation in this section determines that incremental evaluations of DID outlined in NEI 18--04 Section 5.9.3 for plant capability are collectively complete, programmatic actions are appropriate to sustain identified safety significant performance requirements and residual risks are very low.

5.4 Safety Related Structures, Page 46 - Section 5.4 first paragraph text should be in regular font vice in italics since it Paragraph describes how to No change proposed Font and text should be Systems, and provides guidance. The staff will also revise the following text in the TICAP RG regarding display info in the SAR. changed as requested. The Components (SSC) Safety-related SSC discussion in the SAR: The information reflected in Table 5-2, which next to last sentence should be description in the SAR describes combinations of SSCs that are provided in the design to fulfill each RSF and deleted.

identifying whether each set of SSCs is available or not on each of the DBEs, should be included in the application.

6.1.1a Design Basis Hazard Page 52 - The following text should be in regular font vice in italics since it provides Paragraph relates to a No change proposed. Font should be changed as Level discussion in the guidance: Note that this guidance document uses the nomenclature of DBHL instead of departure from NEI 18-04 requested, since it describes SAR the DBEHL term from NEI 18-04. While not discussed comprehensively in NEI 18-04, there affecting LBE scope the scope of DBHLs.

is a need to consider not only hazards external to the plant (traditional external events) but also hazards external to the SSCs performing PRA Safety Functions - i.e., internal plant hazards such as internal fires, floods, turbine missiles, and high energy line breaks. To clarify the original intent of NEI 18-04 to address both categories of hazards, this guidance document uses the DBHL term instead of DBEHL.

This appears to be a deviation from NEI 18-04 and if it is a deviation then it should be noted as such.

6.1.2 Safety related design Page 55 - In the second paragraph, the following text should be regular font because it Font of 1st and 2nd Changes made by TICAP are criteria provides guidance: For each of the RFDC, this section should identify a set of SRDC sentences changed as acceptable since they describe appropriate to the SR SSCs selected to perform the RSFs. These SRDC exclude Special requested. Rest of the scope of SRDC info Treatment Requirements, which are separately covered in Section 6.2. The RFDC, which paragraph not changed required are expressed in the form of functions and involve collections of SSCs and intrinsic capabilities of the plant, may be viewed as a bridge between the RSFs and the SRDC. The SRDC is more detailed requirements for specific SR SSCs in the performance of the RSF functions in specific DBAs. Examples of SRDC that were developed for the MHTGR are found in Appendix A of the LMP SSC report.

It would be more helpful to a user of this guidance document to include some SRDC examples rather than just provide a reference to an external document.

2

NEI 21-07 Section Topic Issue Type TICAP Response NRC Feedback Number 7.1 Reliability and Capability Page 60 - Text in first paragraph should be in No change proposed. OK as is. Sentence can be Targets for NSRST SSCs regular text since it provides guidance considered background.

3