ML25342A020
| ML25342A020 | |
| Person / Time | |
|---|---|
| Issue date: | 12/08/2025 |
| From: | Sheila Ray NRC/NRR/DEX/EEEB |
| To: | |
| Shared Package | |
| ML25342A018 | List: |
| References | |
| RG 1.63, Rev 3 | |
| Download: ML25342A020 (2) | |
Text
Regulatory Guide Number:
1.63, Revision 3
Title:
Electric Penetration Assemblies in Containment Structures for Nuclear Power Generating Stations Office/division/branch:
NRR/DEX/EEEB Technical Lead:
Sheila Ray Staff Action Decided:
Revise
- 1.
What are the known technical or regulatory issues with the current version of the Regulatory Guide (RG)?
RG 1.63, Revision 3 (Rev. 3), Electric Penetration Assemblies in Containment Structures for Nuclear Power Generating Stations, issued in February 1987, provides a method acceptable to NRC staff for complying with the agencys regulations for the design, construction, testing, qualification, and installation of electric penetration assemblies in containment structures in nuclear power plants. The current version of RG 1.63 endorses the Institute of Electrical and Electronic Engineers (IEEE) Standard (Std.)
317-1983, IEEE Standard for the Electric Penetration Assemblies in Containment Structures for Nuclear Power Generating Stations with a clarification. IEEE Std. 317 has been revised in 2013 and 2025, and the current version IEEE Std. 317-2025 has been published. The staff reviewed both the 2013 and 2025 versions and noted some major changes, additions, and clarifications. Specifically, IEEE Std. 317-2025 references the latest standards on environmental qualification, including the joint logo standard International Electrotechnical Commission (IEC)/IEEE Std. 60780-323:2016, Edition 1, Nuclear facilities -- Electrical equipment important to safety - Qualification. In addition, IEEE Std. 317-2025 updated the definitions and considered small modular reactors.
RG 1.63 complements RG 1.89, Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants, which addresses compliance with Title 10 of the Code of Federal Regulations Section 50.49 (10 CFR 50.49),
Environmental Qualification of Electric Equipment Important to Safety for Nuclear Power Plants. RG 1.89, Rev. 2 was issued in 2023 by the NRC (ML22272A602). RG 1.89, Rev. 2, endorses the joint standard IEC/IEEE Std. 60780-323:2016, Edition 1. Due to the technical nexus between RG 1.89 and RG 1.63, RG 1.63 should be updated for technical and regulatory consistency between the RGs that discuss environmental qualification.
- 2.
What is the impact on internal and external stakeholders of not updating the RG for the known issues, in terms of anticipated numbers of licensing and inspection activities over the next several years?
Based on the staffs review, RG 1.63, Rev.3 remains valid, and the use of the current revision of RG 1.63 will have no known impact on internal or external stakeholders at this time. However, the impact of not updating RG 1.63 increases the potential for technical or regulatory challenges because different versions of IEEE standards on environmental qualification are referenced in NRC guidance.
- 3.
What is an estimate of the level of effort needed to address identified issues in terms of full-time equivalent (FTE) and contractor resources?
0.5 FTE and no contractor resources.
- 4.
Based on the answers to the questions above, what is the staff action for this guide (Reviewed with no issues identified, Reviewed with issues identified for future consideration, Revise, or Withdraw)?
Revise.
- 5.
Provide a conceptual plan and timeframe to address the issues identified during the review.
The staff plans to update RG 1.63, Revision 3 and anticipates that the draft guide will be issued for public comment in 2026.
REFERENCES IEEE Std. 317-2025, IEEE Standard for Electric Penetration Assemblies in Containment Structures for Nuclear Power Generating Stations NOTE: This review was conducted in September 2025 and reflects the staffs plans as of that date. These plans are tentative and subject to change.