ML23277A155
| ML23277A155 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/2024 |
| From: | NRC/NRR/DANU/UARP |
| To: | |
| Shared Package | |
| ML23277A105 | List:
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| References | |
| DANU-ISG-2022-08, NRC-2022-0081, ML23277A105 | |
| Download: ML23277A155 (6) | |
Text
1 Analysis of Public Comments on Draft DANU-ISG-2022-08 Advanced Reactor Content of Application Project Risk-Informed Technical Specifications Comments on the draft interim staff guidance (ISG) are available electronically at http://www.nrc.gov/reading-rm/adams.html. From this page, the public can access the Agencywide Documents Access and Management System (ADAMS), which provides text and image files of the U. S.
Nuclear Regulatory Commission (NRC) public documents. The following table lists the comments the NRC received on the draft ISG.
Comment Number ADAMS Accession Number Commenter Affiliation Commenter Name NRC-2022-0081-DRAFT-0001 ML23167A480 Hybrid Power Technologies LLC Michael Keller NRC-2022-0074-DRAFT-0006 ML23229A120 Nuclear Energy Institute Ben Holtzman NRC-2022-0075-DRAFT-0004 ML23234A052 X-energy, LLC Travis Chapman Commenter Identifier Topics Section of Document Specific Comment NRC Staff Response NRC-2022-0081-DRAFT-0001-1 General Not Applicable The NRC is issuing a large number of complicated documents while expecting comments in a short period of time. There is little question that the NRC is attempting to simply short circuit the process of conducting meaningful reviews and providing comments. I seriously doubt the NRC's actions comply with the Nuclear Modernization Act which makes the NRC's actions of doubtful legality. Stagger the documents out over a reasonable time frame.
The NRC staff responded to the request as documented in ML23174A004. As a result of this comment and request from the Nuclear Energy Institute (ML23171B098) the NRC staff extended the comment period for nine interim staff guidance documents and DG 1404, revision 0, from July 10, 2023, to August 10, 2023.
NRC-2022 0074-DRAFT-0006-1 General General Please rephrase to indicate the guidance is technology-inclusive and is equally applicable to both LWR and non-LWR designs.
Throughout all the documents of the package, there are statements that this guidance is applicable to nonLight Water Reactors (LWRs).
However, all the guidance is technology-inclusive and is equally applicable to LWRs. ARCAP is supposed to be applicable for any technology The NRC staff disagrees with the comment.
The NRC staff is considering expanding the applicability of ARCAP guidance documents beyond non-light water reactors (non-LWRs). However, expansion of the guidance beyond non-LWRs at this time is considered premature.
2 Commenter Identifier Topics Section of Document Specific Comment NRC Staff Response (non-LWR and LWR), any licensing approach (LMP, classical, etc.), and any licensing path (CP, COL, DC etc.).
For the ARCAP guidance, industry specifically requested the NRC develop guidance applicable to both non-LWRs and LWR SMRs, and we were informed in various meetings that this would be the NRCs approach. While NEI 18-04 and NEI 21-07 were developed specifically for advanced non-LWRs, applicants with LWR designs should also be able to use the Licensing Modernization Project (LMP) methodology if they elect to do so (e.g., NEI 18-04 and NEI 21-07). It would be up to the applicants to justify the use of the guidance documents and associated regulatory guides.
The final ISG continues to note that the NRC is developing an optional performance-based, technology-inclusive regulatory framework for licensing nuclear power plants designated as 10 CFR Part 53, Licensing and Regulation of Advanced Nuclear Reactors, (RIN 3150-AK31). If the NRC promulgates a final 10 CFR Part 53 rule, the NRC staff plans to apply the 10 CFR Part 53 guidance to both LWRs and non-LWRs. Should the 10 CFR Part 53 rulemaking include requirements for both LWR and non-LWRs, the NRC staff envisions that the guidance documents supporting that rulemaking would provide a basis to expand the concepts found in the ARCAP ISGs guidance beyond non-LWRs. In the interim, the NRC staff notes that the applicability section of the ISG notes that applicants desiring to use the ISG for a light water reactor application should contact the NRC staff to hold pre-application discussions on their proposed approach.
No change to this ISG.
NRC-2022 0074-DRAFT-0006-2 Completion times p.13 NRC should consider providing additional clarification about how the acceptance criteria for CDF and LERF metrics in RG 1.177 should be interpreted with respect to the NEI 18-04 integrated risk metrics. For example, should a licensee interpret the incremental conditional core damage probability (ICCDP) metric in RG 1.177 as directly interchangeable with an incremental conditional latent cancer fatality risk metric?
The NRC staff partially agrees with the comment.
In the near term, the NRC staff has no plans to revise RG 1.177 to address LMP (QHO) criteria. However, to provide additional clarity, the NRC staff revised DANU-ISG-2022-08 to add the following text at the end of item (3) in the section
3 Commenter Identifier Topics Section of Document Specific Comment NRC Staff Response The text states: "RG 1.177, position 2.3.4, references the risk metrics of core damage frequency and large early release frequency based on LWRs as factors in determining completion times. Advanced reactor applicants should use other risk metrics, such as those described in NEI 18-04, for determining completion times."
The NEI 18-04 approach involves direct quantification of risk metrics for comparison to the Quantitative Health Objectives (QHOs): latent cancer fatalities and early fatalities. RG 1.177, Section 2.4, "Acceptance Guidelines for Technical Specification Changes," provides quantitative acceptance criteria for technical specification changes in terms of CDF and LERF. There is interest in NRC development of similar acceptance criteria for the NEI 18-04 latent cancer fatality and early fatality integrated risk metrics.
titled Limiting Condition for Operation Format:
NEI 18-04, Section 3.3.5, Selection of Risk Metrics for PRA Model Development, describes several possible risk metrics (that are different from CDF and LERF metrics developed for LWRs). These metrics could be used by an applicant to develop LCO completion times. Applicants should discuss their proposed risk metrics for developing LCO completion times with NRC staff during preapplication discussions.
NRC-2022 0074-DRAFT-0006-3 PSAR scope
- p. 13-16 Please provide clarification on the level of detail expected, based on the discussion in this draft guidance, for the surveillance requirements, design features, and administrative controls sections of the PSAR TS.
10 CFR 50.34(a)(5) requires An identification and justification for the selection of those variables, conditions, or other items which are determined as the result of preliminary safety analysis and evaluation to be probable subjects of technical specifications for the facility, with special attention given to those items which may significantly influence the final design.
For the surveillance requirements, design features, and administrative controls sections of the PSAR TS; what level of detail does the NRC staff expect to see in the PSAR?
The NRC staff agrees with the comment.
The CP discussion in the Application Guidance section of this ISG is revised to add the following text:
For preliminary safety analysis report (PSAR) technical specifications, information which may significantly influence the final design should be provided in preliminary LCOs, a preliminary list of the types of surveillance tests being considered, and a preliminary description of important design features.
The PSAR technical specifications need not include surveillance requirement frequencies or administrative controls although inclusion of such information, if available, would assist the staff in
4 Commenter Identifier Topics Section of Document Specific Comment NRC Staff Response understanding the design. Furthermore, the PSAR should include a preliminary Technical Specification Bases document to summarize the information in the PSAR on which the preliminary technical specifications are based.
NRC-2022 0074-DRAFT-0006-4 Exemption s
- p. 17 Please clarify whether there is a plan to minimize the need for lengthy and costly exemptions for all non-LWR applicants. Either by revising 50.36 or otherwise.
Item (8) mentions that TS are to meet 50.36, which were developed for LWRs. The draft ARCAP Roadmap DANUISG202201 denotes that this regulation is applicable for non-LWRs but that in some cases, exemptions are expected to be taken.
The comment requests clarification but not of any language in the ISG. At present, the NRC staff does not plan to revise 10 CFR 50.36 to address non-LWR applications. In the Federal Register notice related to this ISG, the staff requested public comment on whether the correlation in the ISG between the 50.36 text and the outputs described in NEI 18-04 can be interpreted as a departure from the regulation text and whether the NRC staff will need to consider whether exemptions are necessary. The staff received no public input on this question. Therefore, the last paragraph of the "Contents of Technical Specifications" section is revised as follows:
To provide suitable guidance on risk-informed TS for advanced reactors, this ISG correlates the text in 10 CFR 50.36 with the analysis and outputs of the risk-informed approach described in NEI 18-04.In some cases, this correlation may be interpreted as inconsistent with the regulation text, in which case the applicant should include an exemption request as part of its application.
5 Commenter Identifier Topics Section of Document Specific Comment NRC Staff Response NRC-2022-0075-DRAFT-0004-34 PSAR scope Pages 13-16 of 20 Please provide clarification on the level of detail expected for the PSAR technical specifications.
For the surveillance requirements, design features, and administrative controls sections of the Preliminary Safety Analysis Report (PSAR) technical specifications, what level of detail does the NRC staff expect to see in the PSAR?
Refer to the response to comment NRC-2022-0074-DRAFT-0006-3.
NRC-2022-0075-DRAFT-0004-35 Exemption s
Page 17 of 20 Please clarify if exemptions will be needed from 50.36 or provide a revision to 50.36 to reflect this ISG and NEI 18-04 to avoid lengthy and costly exemptions.
Item (8) mentions that Technical Specifications (TS) are to meet the regulations in 10 CFR 50.36, which are the TS requirements for LWRs. Is 50.36 going to be revised to reflect NEI 18-04 methodology, or will every advanced reactor applicant require exemptions from 50.36?
Refer to the response to comment NRC-2022-0074-DRAFT-0006-4.
NRC-2022-0075-DRAFT-0004-36 Completion times Page 13 of 20 Please provide additional clarification about how the acceptance criteria for CDF and LERF metrics in RG 1.177 should be interpreted with respect to the NEI 18-04 integrated risk metrics. For example, should a licensee interpret the incremental conditional core damage probability (ICCDP) metric in RG 1.177 as directly interchangeable with an incremental conditional latent cancer fatality risk metric?
The guidance states, "RG 1.177, position 2.3.4, references the risk metrics of core damage frequency and large early release frequency based on LWRs as factors in determining completion times. Advanced reactor applicants should use other risk metrics, such as those described in NEI 18-04, for determining completion times." The NEI 18-04 approach involves direct quantification of risk metrics for comparison to the Quantitative Refer to the response to comment NRC-2022-0074-DRAFT-0006-2.
6 Commenter Identifier Topics Section of Document Specific Comment NRC Staff Response Health Objectives (QHOs): latent cancer fatalities and early fatalities. RG 1.177, Section 2.4, "Acceptance Guidelines for Technical Specification Changes" provides quantitative acceptance criteria for technical specification changes in terms of CDF and LERF. X-energy is interested in NRC development of similar acceptance criteria for the NEI 18-04 latent cancer fatality and early fatality integrated risk metrics.