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{{#Wiki_filter:APPENDIX X NRC REGULATORY POSITION ON NEI 21-07, REVISION 0, TECHNOLOGY INCLUSIVE GUIDANCE FOR NON-LIGHT WATER REACTORS SAFETY ANALYSIS REPORT CONTENT FOR APPLICANTS USING THE NEI 18-04 METHODOLOGY Introduction The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed Nuclear Energy Institute (NEI) 21-07, Revision 0, Technology Inclusive Guidance for Non-Light Water Reactors Safety Analysis Report Content for Applicants Using the NEI 18-04 Methodology. The purpose of this appendix is to supplement the Regulatory Positions discussed in Regulatory Positions C.1 through C.8 of this RG. The staffs detailed position on that applicable portions of NEI 21-07, Revision 0 are found in the following table. The table notes areas where the staff has identified an exception, clarification, addition, or comment/suggested edit. The definition of these terms is as follows:
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* Exception - feedback labeled as an NRC Exception is used to highlight statements, or portions thereof, in NEI 21-07 that are factually incorrect or guidance that would result in the need for an NRC Request for Additional Information (RAI) if followed by an applicant in developing a safety analysis report (SAR).
* Clarification - feedback labeled as an NRC Clarification is used to indicate statements or guidance in NEI 21-07 that are ambiguous and would require clarification by the NRC to limit the possible interpretations by an applicant or other stakeholder consulting NEI 21-07. An applicant relying on NEI 21-07 to develop an application in the absence of the Clarification would likely be subject to RAIs if the guidance was improperly interpreted. Similarly, stakeholders consulting NEI 21-07 in the absence of the Clarification could conclude that publicly available application information is inadequate to the extent that it could form the basis for a contention.
* Addition - feedback labeled as an NRC Addition is used to indicate staff regulatory guidance that should be followed by an applicant in addition to the guidance in NEI 21-07 in order to develop a SAR that addresses their safety case. Additions not related to the LMP-based affirmative safety case will be included in the ARCAP guidance.
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NRC Draft NEI 21-07, Revision 0 Exceptions, Clarifications, Additions, and Comment/Suggested Edit NEI 21-07 Topic                        Discussion                                                                                                                Type              Disposition (i.e.,
Section                                                                                                                                                                            addressed in NEI Number ID                                                                                                                                                                          21-07, Revision 1 or included in this RG)
A.2    Background                    Page 3 (last paragraph) - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper Clarification to clarify that in addition to making a safety case, an applicant should also make a licensing case that focuses on compliance with applicable regulations and includes any exemptions, as necessary.
A.3a    Supplemental information      Page 3 Clarification and addition. The staff will continue to reference in its TICAP RG the guidance that is relevant to  Clarification and affecting first 8 chapters of the first 8 chapters of the SAR (e.g., siting, fuel qualification, instrumentation and control design review guide, ASME  Addition the SAR outside the scope    Section III Division 5). See supplemental information found in 7/8 version of TICAP RG draft white paper of Industry TICAP guidance    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 RG white paper to clarify that  Clarification that an affirmative safety case should include normal 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 TICAP draft RG white paper to      Clarification clarify that an affirmative safety case should include normal operation as well as LBEs.
B.3    Explanation and Use of text  Page 9 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper clarifying the  Clarification that is in italics            meaning of the use of the regular text and text in italics throughout the SAR content guidance in Section C of NEI 21-
: 07. Examples of text that the staff believes should be in regular font vice in italics include:
NEI 21-07        Topic                        Issue Section Number 1a              Guidance in                  The fourth, fifth, and sixth paragraphs of this section should be regular Introduction Section        text since they provide instructions for the applicant regarding should be regular font.      information to be included, formatting, and level of detail.
2b              Discussion of topical        Page 21 - topical reports approved by the NRC during pre-application reports                      engagement activities should be incorporated by reference into the SAR and not simply be listed as general references. Applicants should 2
 
NEI 21-07 Topic Discussion                                                                                                      Type Disposition (i.e.,
Section                                                                                                                            addressed in NEI Number ID                                                                                                                            21-07, Revision 1 or included in this RG) specifically identify documents IBRd into the SAR. The staff also believes the sentence should be in regular text.
3        Guidance regarding      Page 27 - The third paragraph should be in regular font because it licensing basis events  provides guidance regarding LBEs.
should be regular font 3.6      DBA guidance should be  Page 35 - The fourth paragraph in this section should be regular font regular font.          because it provides guidance regarding the documentation of conservative deterministic DBA analyses that is generally modeled after accident analysis descriptions found in Chapter 15 of SARs for current LWRs.
4.2a      Guidance regarding DID  Page 38- the final sentence in the first paragraph of Section 4.2 should be should be regular font. in regular font because it provides guidance.
4.2b      Defense in depth        Page 39 - the second paragraph of Section 4.2 and the bulleted list discussion and          immediately below it should be in regular font and not in italics since it clarification that some provides guidance.
of the guidance should be in regular text      The sixth bullet of this list should be modified to read, Evaluation of single features that are risk significant to assure no overdependence on that feature ."
The first sentence of the paragraph following these bullets in Section 4.2 should be revised to state: Note that the information responsive to this bulleted list should be provided in either this chapter or in Chapters 3, 5, 6, 7, and 8.
4.2.1    DID plant capability    Page 40 - portion of second paragraph should be in regular font because summary                it provides guidance 4.2.1.2  DID guidance should be  Page 41 - The first paragraph in this section should be regular font regular font.          because it provides guidance regarding the DID evaluation.
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NEI 21-07 Topic Discussion                                                                                                        Type Disposition (i.e.,
Section                                                                                                                              addressed in NEI Number ID                                                                                                                              21-07, Revision 1 or included in this RG) 4.2.2a    Defense in Depth          Page 42 and 43, the second paragraph in Section 4.2.2, which starts with Summary discussion in    Programmatic DID should be used ... should be in regular font and not the SAR                  in italics since it provides guidance.
4.2.3b    Integrated defense in    Page 44, the following text should be in regular font and not in italics depth discussion in the  since it provides guidance: The baseline DID evaluation results in the SAR SAR                      reflect the finalization of all DID adequacy evaluations. The evaluation in this section determines that incremental evaluations of DID outlined in NEI 1804 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.
4.2.2.1  Evaluation of Significant Page 44 - Further discussion in needed in either NEI 21-07, Revision 1 or Uncertainties            the TICAP draft RG white paper to document that The consideration of uncertainties may also identify 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            Page 45 - the following text should be in regular font and not in italics evaluation                since it provides guidance: The baseline DID evaluation results in the SAR reflect the finalization of all DID 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            Page 49 - Section 5.4 first paragraph text should be in regular font vice in Structures, Systems, and italics since it provides guidance. The staff will also revise the following Components (SSC)          text in the TICAP RG regarding Safety-related SSC discussion in the SAR:
description in the SAR    The information reflected in Table 5-2, which describes combinations of SSCs that are provided in the design to fulfill each RSF and identifying 4
 
NEI 21-07 Topic Discussion                                                                                                              Type Disposition (i.e.,
Section                                                                                                                                      addressed in NEI Number ID                                                                                                                                    21-07, Revision 1 or included in this RG) 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 55 - The following text should be in regular font vice in italics since it Level discussion in the provides guidance: Note that this guidance document uses the nomenclature of SAR                    DBHL instead of the DBEHL term from NEI 18-04. While not discussed comprehensively in NEI 18-04, there 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    Guidance regarding      Page 57 - In the second paragraph, the following text should be regular SRDC description should font because it provides guidance: For each of the RFDC, this section be regular font        should identify a set of SRDC appropriate to the SR SSCs selected to perform the RSFs. These SRDC exclude Special Treatment Requirements, which are separately covered in Section 6.2. The RFDC, which 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.
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NEI 21-07 Topic                      Discussion                                                                                                                Type              Disposition (i.e.,
Section                                                                                                                                                                          addressed in NEI Number ID                                                                                                                                                                        21-07, Revision 1 or included in this RG) 7.1          Reliability and Capability  Page 63 - Text in first paragraph should be in regular text since it Targets for NSRST SSCs      provides guidance B.5    Two-Step Licensing (CP/OL)  Page 10 - Clarification of several items should be made: (1) the requirement under 50.34(a)(4) for demonstration of an    Clarification and affirmative safety case that includes normal operation reflecting that LMP does not address normal operation; (2) a      Addition licensing case also needs to be made by the applicant with respect to claims of compliance with or requests for exemption from regulations; and (3) the COL application scope includes 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 draft RG white paper to clarify  Clarification and that the SAR content developed through use of LMP is similar in scope only to the Tier 2 information required for a DC    Addition 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 16 - Clarify what language in Chapter 1 of a SAR will be included and maintained as part of the licensing basis,    Clarification and what parts of the regulation those parts seek to fulfill.
1.1.2  Intended Use of the Reactor Page 17 - The NEI proposed text does not seem to fully address 10 CFR 50.34(a)(1)(ii)(A) regarding use of the reactor. Addition Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to address the radioactive materials inventory portion of the regulation.
1.3.3  Defense in Depth            Page 21 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to clarify that Clarification and DID adequacy is based on 3-elements; plant capability DID, programmatic DID, and RIPB DID. Applicants should              Addition address risk-informed, performance-based DID also and cite key examples for this DID element 6
 
NEI 21-07 Topic                      Discussion                                                                                                                    Type              Disposition (i.e.,
Section                                                                                                                                                                            addressed in NEI Number ID                                                                                                                                                                            21-07, Revision 1 or included in this RG) 2a    Pre-licensing engagement  Page 21 - The highlighted sentence gives the incorrect perception that pre-licensing interactions affect the level of        Clarification detail that should be provided within the docketed license application and related submittals (e.g., topical reports) 2.1  PRA discussion to be      Page 22- The fourth and fifth sentences in the first paragraph of Section 2.1 provide guidance and should therefore be        Clarification included in the SAR        in regular text. In order to reflect the Commissions affirmation in SRM-SECY-2015-002 regarding the need for 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 22 and 23 - Trial-use RG 1.247 to endorse the std is under development. NRC staff positions in RG 1.247, once            Clarification deviations) with the      issued, should be addressed along with the Std.
advanced non-LWR PRA standard, ASME/ANS RA-S-  NEI 20-09, Revision 1, has been submitted to the NRC for endorsement. Revision 1 should be cited instead of Revision 1.4-2021                  0.
NEI 20-09, Rev. 0 PRA peer review 2.1.1b  Discussion of PRA          Page 23 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper to cover the      Clarification and information to be included level of detail for the PRA information to be included in the SAR as follows: This section should describe PRA              Addition in the SAR                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  Page 24 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG with paper to clarify the    Clarification and SAR - Two-step licensing  basis for omitting peer review for PRA for a CP application as follows (italics are used to set off the clarification - final Addition (CP application)          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        Page 24 - The last bullet in this section states that SAR Chapters 6 and 7 are to address reliability and capability targets  Clarification and Results                    for SR and NSRST SSCs. Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper      Addition to address SR and NSRST human actions.
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NEI 21-07 Topic                          Discussion                                                                                                                    Type              Disposition (i.e.,
Section                                                                                                                                                                                addressed in NEI Number ID                                                                                                                                                                                21-07, Revision 1 or included in this RG) 3.3    Anticipated operational        Page 31 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to clarify that    Clarification occurrences (AOOs) -          non-DBA LBE as analyzed in the PRA should be summarized in the SAR.
clarification of discussion of 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 RG white paper to clarify that    Clarification and regarding AOOs should be      a description of the models, site characteristics, and supporting data associated with the calculation of the mechanistic    Exception captured in the SAR            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 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 RG white paper to document        Clarification and key information regarding      the need for a description of the models, site characteristics, and supporting data associated with the calculation of        Exception DBEs should be captured in    the mechanistic source terms and radiological consequences for DBEs with a release (to the extent such information is the SAR                        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, 8
 
NEI 21-07 Topic                      Discussion                                                                                                              Type              Disposition (i.e.,
Section                                                                                                                                                                        addressed in NEI Number ID                                                                                                                                                                        21-07, Revision 1 or included in this RG) 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 paper to document    Clarification and (BDBEs) - key information  the need for a description of the models, site characteristics, and supporting data associated with the calculation of  Exception regarding BDBEs should be  the mechanistic source terms and radiological consequences for BDBEs with a release (to the extent such information captured in the SAR        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., 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 Page 37 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to document    Addition risk information found in  the need for a discussion of the following items where different from the analysis performed under Chapter 3:
the SAR
* 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.
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NEI 21-07 Topic                      Discussion                                                                                                                Type          Disposition (i.e.,
Section                                                                                                                                                                      addressed in NEI Number ID                                                                                                                                                                    21-07, Revision 1 or included in this RG) 4.2.1  Guidance for DID evaluation Page 40- Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to document      Clarification 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      Page 43 - ADAMS ML numbers or hyperlinks to referenced documents and reports should be added to promote                  Clarification Balance                    efficient user interface with this guidance document.
4.2.2b  Guidance for programmatic  Page 44 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to document    Clarification DID added                  that The applicant should provide the justification for where 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              Page 44, Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper to state that  Addition Considerations - SR SSC    an applicant should include the description of programs to assure human performance for risk-significant functions performance Monitoring      should address human factors considerations such as operating experience review, safety function review, human action task analysis, human system interface design, procedures, training and V&V, human performance monitoring (where not described in Chapter 6).
4.2.2.3  Human Factors              Page 45, Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper to state that  Addition Considerations - NSRST SSC  an applicant should include the description of programs to assure human performance for safety-significant functions performance monitoring      should address human factors considerations such as operating experience review, safety function review, human action task analysis, human system interface design, procedures, training and V&V, human performance monitoring (where not described in Chapter 7).
4.2.3b  Integrated defense in depth Page 45 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to document    Addition discussion in the SAR      that an applicant should address the following to describe how the integrated DID analysis meets the standards in NEI 18-04: The applicant should summarize how the integrated DID process was applied in evaluating the overall adequacy of DID. The description should address how each of the decision guidelines listed in NEI 18-04, 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 integrated DID process are documented and available for future DID decision-making and operations support should also be provided.
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NEI 21-07 Topic                      Discussion                                                                                                              Type                      Disposition (i.e.,
Section                                                                                                                                                                                addressed in NEI Number ID                                                                                                                                                                                21-07, Revision 1 or included in this RG) 4.2.3c  Added guidance to include a Page 46 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to document    Clarification and description of the change  that an applicant should include a discussion of the change process associated with defense in depth analysis            Addition process to defense in depth described in Section 4.2.3 of the NEI guidance document: The change control process should be described addressing discussion found in the SAR how the baseline DID evaluation will be re-evaluated, based on proposed changes, to determine which programmatic or plant capability attributes have been affected for each layer of defense. Changes that impact the definition and evaluation of LBEs, safety classification of SSCs, or risk significance of LBEs or SSCs should be assessed.
5.3    Principal Design Criteria  Page 47 and 48- considering whether following proposed addition is appropriate related to PDC guidance: These LMP      Note - staff still (PDC)                      derived requirements may be considered together with generic applicable Advanced Reactor Design Criteria (ARDC) in      developing position formulating the principal design criteria for the license application. When considering the use of generic ARDC for this and path forward purpose, the LMP methodology does not include the application of the Single Failure Criterion (SFC) that is included in  regarding PDC the ARDC language. In the LMP approach to formulating design requirements for SSCs, reliability and capability targets  guidance. It is unclear are used to inform the selection of special treatment requirements. This obviates the need to applying the SFC. Hence    at this point as to when ARDCs are considered in developing the principal design criteria, the SFC language should be removed.              whether an exception, clarification or addition Last sentence, third paragraph proposed edits to be more consistent with stated NRC positions:                          (or a combination of However, the General Design Criteria and Advanced Reactor Design Criteria are intended to provide guidance in            these) will be included establishing the principal design criteria for non-LWR designs.                                                          in the staff TICAP RG Fourth paragraph proposed edits to be more consistent with stated NRC positions. Proposed revised paragraph 5.5.1  Non Safety Related SSCs    Page 51 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to document    Addition performing risk significant that information similar to that found in Tables 5-1 and 5-2 for safety related SSCs should be provided for non-safety functions discussion in the related SSCs performing a risk-significant function.
SAR 11
 
NEI 21-07 Topic                        Discussion                                                                                                                  Type              Disposition (i.e.,
Section                                                                                                                                                                            addressed in NEI Number ID                                                                                                                                                                            21-07, Revision 1 or included in this RG) 5.6a  Complimentary Design        Page 53 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper regarding      Clarification and Criteria (CDC) discussion in CDC information that should be provided in the SAR, similar to the comments provided in an August 13, 2021, email          Addition the SAR                      that was discussed during an August 17, 2021, public meeting (see:
https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=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 PDCs and (c) when they are defined at the PRA Safety Function level, they are considered subparts of a higher level PDC. In addition, the TICAP Guidance Document text should provide examples of both types of defined CDCs.
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 53 - Language should be added to clarify that NSRST SSCs may be included within the PDC rather than being              Clarification limited to inclusion in the CDCs.
5.6c  CDC discussion in SAR        Page 53 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to clarify that  Clarification the importance and contribution of engineering criteria for the 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 CDCs. The focus is on the engineering criteria for the design rather than inclusion of SSCs as part of CDCs or PDCs. It is clear from the LMP process that NSRST SSCs are necessary for either PRA Safety Functions or DID. Inclusion of CDCs 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 56 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to clarify that  Clarification discussion in the SAR        the SAR Should include discussion regarding the calculation methodology for DBHLS loads on the SSCs Calculation methodology has traditionally been part of the licensing basis. For example, where the methodology for combining loads is either ABSUM (absolute summation) or 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.
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NEI 21-07 Topic                        Discussion                                                                                                                Type              Disposition (i.e.,
Section                                                                                                                                                                            addressed in NEI Number ID                                                                                                                                                                            21-07, Revision 1 or included in this RG) 6.1.1c  Design Basis Hazard Level    Page 56 - Further discussion is necessary in either NEI 21-07, Revision 1, or in TICAP draft RG white paper to clarify    Clarification and discussion in the SAR        that an applicant should summarize the basis for the DBHLs in the SAR.                                                    Addition 6.1.1d  Editorial correction to Table Page 56 - verify that the table title and the second column heading should exclude the term external.                    Clarification 6-1 6.3/7.2  FOAK SR SSCs and NSRST        Page 60 and 63 - Text suggests incomplete Validation and Verification tests can be covered under special treatment at      Clarification and SSCs                          the submittal of a license application. Staff suggests an addition / revision to the text to include the timing of the NRC Addition SER and the possibility of license conditions, consistent with 50.43(e).
6.4.1a  Human Factors                Page 62 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to clarify that  Addition Considerations - SR SSCs      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                Page 65 - Further discussion is needed in either NEI 21-07, Revision 1, or the TICAP draft RG white paper to clarify that  Addition Considerations - NSRST        where human actions perform PRA safety functions, the description of controls and displays should address human SSCs                          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 61 and 65 - These sections list the design aspects of the various SR and NSRST SSCs, including human actions.        Addition 7.3.1b  Capability                    Further discussion is needed in either NEI 21-07, Revision 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 because the agency does not              Clarification endorse examples provided in guidance documents due to the need for technical review and approval.
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Revision as of 19:57, 16 January 2022

Table Containing Draft Exceptions, Clarifications, and Additions, Related to NEI 21-07, Revision 0, Technology Inclusive Guidance for Non-Light Water Reactors Safety Analysis Report Content for Applicants Using the NEI 18-04 Methodology
ML21274A032
Person / Time
Issue date: 10/01/2021
From:
Office of Nuclear Reactor Regulation
To:
Sebrosky J
Shared Package
ML21274A029 List:
References
NEI 18-04, NEI 21-07, Rev 0
Download: ML21274A032 (13)
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