SUPPLEMENTARY INFORMATION:

I. Obtaining information and Submitting Comments

A. Obtaining Information

Please refer to Docket ID NRC-2022-0215 when contacting the NRC about the availability of information for this action. You may obtain publicly available information related to this action by any of the following methods:

• Federal Rulemaking Website: Go to www.regulations.gov and search for Docket ID NRC-2022-0215.
• NRC's Agencywide Documents Access and Management System (ADAMS): You may obtain publicly available documents online in the ADAMS Public Documents collection at www.nrc.gov/​reading-rm/​adams.html. To begin the search, select “Begin ADAMS Public Search.” For problems with ADAMS, please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, or by email to PDR.Resource@nrc.gov. The ADAMS accession number for each document referenced (if it is available in ADAMS) is provided the first time that it is mentioned in this document.
• NRC's PDR: The PDR, where you may examine and order copies of publicly available documents, is open by appointment. To make an appointment to visit the PDR, please send an email to PDR.Resource@nrc.gov or call 1-800-397-4209 or 301-415-4737, between 8 a.m. and 4 p.m. eastern time (ET), Monday through Friday, except Federal holidays.

B. Submitting Comments

The NRC encourages electronic comment submission through the Federal rulemaking website ( www.regulations.gov). Please include Docket ID NRC-2022-0215 in your comment submission.

The NRC cautions you not to include identifying or contact information that you do not want to be publicly disclosed in your comment submission. The NRC will post all comment submissions at www.regulations.gov as well as enter the comment submissions into ADAMS. The NRC does not routinely edit comment submissions to remove identifying or contact information.

If you are requesting or aggregating comments from other persons for submission to the NRC, then you should inform those persons not to include identifying or contact information that they do not want to be publicly disclosed in their comment submission. Your request should state that the NRC does not routinely edit comment submissions to remove such information before making the comment submissions available to the public or entering the comment into ADAMS.

II. Background

As part of its review of advanced non-light water reactor applications, the NRC staff evaluates materials performance to ensure passive components fulfill design requirements for the design life, and that adequate surveillance and monitoring programs are in place. NRC regulations in parts 50, 52, and 53 of title 10 of the Code of Federal Regulations (10 CFR) describe the information applicants must include in applications for construction permits, operating licenses, combined operating licenses, standard design approvals, standard design certifications, and manufacturing licenses. This includes information related to requirements to ensure passive materials performance and performance monitoring. The NRC endorsed, with exceptions and limitations, American Society of Mechanical Engineers (ASME) Code Section III, Division 5, “High Temperature Reactors” (III-5), with conditions, in Revision 3 of Regulatory Guide (RG) 1.87, “Acceptability of ASME Code, Section III, Division 5, `High Temperature Reactors,'” (ADAMS Accession No. ML25176A084) for use by non-LWR applicants and licensees subject to 10 CFR parts 50 and 52. The NRC staff has not endorsed this document for use by applicants and licensees subject to 10 CFR part 53. The NRC staff is currently considering whether to endorse both III-5 for applicants and licensees subject to 10 CFR part 53. If, based on the NRC staff's review, the NRC staff determines that it cannot endorse either III-5 for use by applicants and licensees subject to 10 CFR part 53, it will revise this ISG accordingly before issuing it for use.

This revision to DANU-ISG-2023-01 adds an appendix providing risk-informed guidance on information related to materials performance that applicants should include in various applications. It also updates miscellaneous information and extends the ISG's applicability to applications under 10 CFR part 53.

III. Discussion

The purpose of this draft ISG, “Material Compatibility for non-Light-Water Reactors, DANU-ISG-2023-01, Revision 1” (ADAMS Accession No. ML26155A114), is to aid the NRC staff reviewing non-light water reactor applications for permits, licenses, certifications, and approvals under 10 CFR parts 50, 52 and 53. III-5 and other codes and standards used for the design and construction of mechanical components specify the mechanical properties and allowable stresses for design of components in high temperature reactors. Because III-5 and other design and construction codes and standards do not provide methods to evaluate deterioration that may occur in service as a result of corrosion, mass transfer phenomena, radiation effects, or other material instabilities, this draft ISG revision identifies information that the staff should consider as part of its evaluation of a non-light water reactor application with respect to applicable design requirements including materials performance, environmental compatibility, and performance monitoring programs for safety-significant SSCs.

This revision of DANU-ISG-2023-01 adds an appendix to provide guidance related to information the NRC staff generally have used to perform the review of materials of construction and passive SSC performance for non-LWRs. This appendix provides guidance across key application content areas for materials performance, including description of the design and operating environment as well as performance evaluation and monitoring. Description of the design and operating environment includes identification of materials of construction, identification of ( printed page 59815) environmental conditions, and use of codes and standards. Performance evaluation and monitoring covers primarily an environmental compatibility assessment and performance monitoring. The appendix concludes with tables providing guidance on what information is acceptable at the preliminary and final design stages across these key application content areas as a function of safety significance.

In addition to adding the appendix, this revision also makes the ISG applicable to applications under 10 CFR part 53 and makes other miscellaneous changes to the ISG.

(Authority: 42 U.S.C. 2011 et seq.)

91 FR 59813