[Federal Register Volume 90, Number 168 (Wednesday, September 3, 2025)]
[Notices]
[Pages 42627-42628]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-16899]


-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

[NRC-2024-0203]


Regulatory Guide: Acceptability of ASME Code, Section III, 
Division 5, ``High Temperature Reactors''

AGENCY: Nuclear Regulatory Commission.

ACTION: Final guide; issuance.

-----------------------------------------------------------------------

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing 
Revision 3 to Regulatory Guide (RG), 1.87, ``Acceptability of ASME 
Code, Section III, Division 5, ``High Temperature Reactors.'''' This 
regulatory guide (RG) describes an approach that is acceptable to the 
staff of the NRC to assure the mechanical/structural integrity of 
components that operate in elevated temperature environments and that 
are subject to time-dependent material properties and failure modes. It 
endorses, with exceptions and limitations, the American Society of 
Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code (ASME 
Code) Section III, ``Rules for Construction of Nuclear Facility 
Components,'' Division 5, ``High Temperature Reactors,'' and several 
related Code Cases.

DATES: Revision 3 to RG 1.87 is available on September 3, 2025.

ADDRESSES: Please refer to Docket ID NRC-2024-0203 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly available information related to this document 
using any of the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2024-0203. Address 
questions about Docket IDs in Regulations.gov to Bridget Curran; 
telephone: 301-415-1003; email: [email protected]. For technical 
questions, contact the individual(s) listed in the For Further 
Information Contact section of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection at https://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 [email protected]. 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 
[email protected] 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.
    Revision 3 to RG 1.87 and the regulatory analysis may be found in 
ADAMS under Accession Nos. ML25176A084 and ML24275A267, respectively.
    Regulatory guides are not copyrighted, and NRC approval is not 
required to reproduce them.

FOR FURTHER INFORMATION CONTACT: Ram[oacute]n L Gascot Lozada, Office 
of Nuclear Regulatory Research, telephone: 301-415-2004; email: 
[email protected]; Joseph Bass, Office of Nuclear Regulatory 
Research, telephone: 301-287-9278; email: [email protected] or 
Margaret Audrain, Office of Nuclear Reactor Regulation, telephone: 301-
415-2133; email: [email protected]. All are staff of the U.S. 
Nuclear Regulatory Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION:

I. Discussion

    The NRC is issuing a revision in the NRC's ``Regulatory Guide'' 
series. This series was developed to describe methods that are 
acceptable to the NRC staff for implementing specific parts of the 
agency's regulations, to explain techniques that the staff uses in 
evaluating specific issues or postulated events, and to describe 
information that

[[Page 42628]]

the staff needs in its review of applications for permits and licenses.
    The proposed Revision 3 to RG 1.87 was issued with a temporary 
identification of Draft Regulatory Guide, DG-1436 (ADAMS Accession No. 
ML24275A266). This revision (Revision 3) updates the guidance to 
endorse, with exceptions and limitations, the 2023 Edition of ASME Code 
Section III, Division 5, as a method acceptable to the staff for the 
materials, mechanical/structural design, construction, testing, and 
quality assurance of mechanical systems and components and their 
supports in high-temperature reactors. This revision removes conditions 
from Revision 2 of the RG that have been addressed in the 2023 version 
of the Code. This revision also endorses, with exceptions and 
limitations, the Code Cases N-812-1, N-861-2, N-862-2, N-872, N-898-1, 
N-924 and N-940.

II. Additional Information

    The NRC published a notice of the availability of DG-1436 in the 
Federal Register on December 13, 2024 (89 FR 100921) for public 
comment. The NRC extended the public comment period on February 3, 2025 
(90 FR 8782). The public comment period closed on February 26, 2025. 
Public comments on DG-1436 and the staff responses to the public 
comments are available in ADAMS under Accession No. ML25188A048.

III. Congressional Review Act

    This RG is a rule as defined in the Congressional Review Act (5 
U.S.C. 801-808). However, the Office of Management and Budget has not 
found it to be a major rule as defined in the Congressional Review Act.

IV. Backfitting, Forward Fitting, and Issue Finality

    The NRC staff may use this RG as a reference in its regulatory 
processes, such as licensing, inspection, or enforcement. However, the 
NRC staff does not intend to use the guidance in this RG to support NRC 
staff actions in a manner that would constitute backfitting as that 
term is defined in section 50.109 of title 10 of the Code of Federal 
Regulations (10 CFR), ``Backfitting,'' and as described in NRC 
Management Directive (MD) 8.4, ``Management of Backfitting, Forward 
Fitting, Issue Finality, and Information Requests,'' (Ref. 11); nor 
does the NRC staff intend to use the guidance to affect the issue 
finality of an approval under 10 CFR part 52, ``Licenses, 
Certifications, and Approvals for Nuclear Power Plants.'' The staff 
also does not intend to use the guidance to support NRC staff actions 
in a manner that constitutes forward fitting as that term is defined 
and described in MD 8.4. If a licensee believes that the NRC is using 
this RG in a manner inconsistent with the discussion in the 
Implementation section of this RG, then the licensee may file a 
backfitting or forward fitting appeal with the NRC in accordance with 
the process in MD 8.4.

V. Submitting Suggestions for Improvement of Regulatory Guides

    A member of the public may, at any time, submit suggestions to the 
NRC for improvement of existing RGs or for the development of new RGs. 
Suggestions can be submitted on the NRC's public website at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/contactus.html. 
Suggestions will be considered in future updates and enhancements to 
the ``Regulatory Guide'' series.

VI. Executive Order (E.O.) 12866

    The Office of Information and Regulatory Affairs determined that 
this RG is not a significant regulatory action under E.O. 12866.

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

    Dated: August 29, 2025.

    For the Nuclear Regulatory Commission.
Meraj Rahimi,
Chief, Regulatory Guide and Programs Management Branch, Division of 
Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2025-16899 Filed 9-2-25; 8:45 am]
BILLING CODE 7590-01-P