ML24158A062
| ML24158A062 | |
| Person / Time | |
|---|---|
| Issue date: | 08/21/2024 |
| From: | Mohammad Sadollah NRC/RES/DE/CIB |
| To: | |
| Shared Package | |
| ML22202A001 | List: |
| References | |
| RG-1.032, Rev 4 DG-1420 | |
| Download: ML24158A062 (3) | |
Text
REGULATORY ANALYSIS DRAFT REGULATORY GUIDE DG-1420 CRITERIA FOR POWER SYSTEMS FOR NUCLEAR POWER PLANTS (Proposed Revision 4 of Regulatory Guide 1.32, Dated March 2002, and Inclusion of the Provisions of Regulatory Guide 1.41, dated March 1973)
- 1. Introduction This document presents the results of a regulatory analysis of the U.S. Nuclear Regulatory Commissions (NRCs) determination of whether to issue Draft Regulatory Guide (DG)-1420, Criteria for Power Systems for Nuclear Power Plants. The proposed revision will also include consolidation of provisions of Regulatory Guide (RG) 1.41, Preoperational Testing of Redundant On-Site Electric Power Systems to Verify Proper Load Group Assignments, which is proposed to be withdrawn with the issuance of Revision 4 to RG 1.32 Criteria for Power Systems for Nuclear Power Plants. The analysis provides the public with an insight in how the NRC arrives at a decision.
- 2.
Statement of the Problem The U.S. Nuclear Regulatory Commission (NRC) is considering revising RG 1.32, Criteria for Power Systems for Nuclear Power Plants, to endorse (with exception) the latest version of the subject IEEE Standard (IEEE Std. 308-2020, IEEE Standard Criteria for Class 1E Power Systems for Nuclear Power Generating Stations published March 16, 2020), and to incorporate provisions of RG 1.41, Preoperational Testing of Redundant On-Site Electric Power Systems to Verify Proper Load Group Assignments, which is proposed to be withdrawn along with the issuance of Revision 4 to RG 1.32.
The NRC issued Revision 3 of RG 1.32, Criteria for Power Systems for Nuclear Power Plants in March 2002. Revision 3 of RG 1.32 endorsed (with exception) IEEE Std. 308 - 2001, Criteria for Class 1E Power Systems for Nuclear Power Generating Stations. The current version of RG 1.32 (Revision 3) does not address the latest version of the IEEE Standard which was issued in March 2020.
The NRC also issued RG 1.41, Preoperational Testing of Redundant On-Site Electric Power Systems to Verify Proper Load Group Assignments, in March 1973. For increased efficiency and clarity, it is deemed prudent to withdraw RG 1.41 and incorporate its provisions of preoperational testing into proposed Revision 4 of RG 1.32.
- 3.
Objective The objective of this regulatory action is to assess the need to update NRC guidance and provide applicants with a method to demonstrate compliance with the 10 CFR Part 50 and 10 CFR Part 52 requirements for the design, operation, and testing of electric power systems in nuclear power plants. Specifically, it provides guidance for meeting the General Design Criteria for the safety-related portions of systems and equipment in the alternating current power systems, direct current power systems, and power systems for instrumentation and control devices.
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- 4.
Identification and Analysis of Alternative Approaches The NRC staff considered the following alternative approaches:
- 1. Do not revise RG 1.32
- 2. Withdraw RG 1.32
- 3. Revise RG 1.32 to address the current methods and procedures.
Alternative 1: Do Not Revise RG 1.32 Under this alternative, the NRC would not revise guidance, and the current guidance would be retained. If NRC does not take action, there would not be any changes in costs or benefit to the public, applicant, licensees or NRC. This alternative is considered the no-action alternative and provides a baseline condition from which any other alternatives will be assessed.
However, the no-action alternative would not address identified concerns with the current version of the regulatory. The NRC would continue to review each application on a case-by-case basis.
Alternative 2: Withdraw RG 1.32 Under this alternative the NRC would withdraw this RG. This would eliminate the problems identified above regarding the RG. It would also eliminate the only readily available description of the methods the NRC staff considers acceptable for demonstrating compliance with 10 CFR Part 50 and 10 CFR Part 52 requirements for the design, operation, and testing of electric power systems in nuclear power plants. Specifically, RG 1.32 provides guidance for meeting the General Design Criteria for the safety-related portions of systems and equipment in the alternating current power systems, direct current power systems, and power systems for instrumentation and control devices. Although this alternative would be less costly than the proposed alternative, it would impede the NRC staffs as well as the publics accessibility to the most current regulatory guidance.
Alternative 3: Revise RG 1.32 Under this alternative, the NRC would revise RG 1.32. This revision would incorporate the latest information in the IEEE Std. 308 - 2020 supporting guidance, and review practices.
Additionally, RG 1.41 will be withdrawn, and its provisions will be consolidated in the new revision of RG 1.32. By doing so, the NRC would ensure that the RG guidance available in this area is current, and accurately reflects the staffs position.
The impact to the NRC would be the costs associated with preparing and issuing the RG revision. The impact to the public would be the voluntary costs associated with reviewing and providing comments to the NRC during the public comment period. The value to NRC staff and its applicants and licensees would be the benefits associated with enhanced efficiency and effectiveness in using a common guidance document as the technical basis for license applications, licenses, and other interactions between the NRC and its regulated entities.
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- 5.
Comparison of Alternatives The alternatives were compared against each other with respect to safety, as well as NRCs and applicant/licensees resources.
With respect to safety, Alternative 1 does not signify unsafe results since applicants and licensees would adopt methods that would be evaluated by NRC staff on a case-specific basis to establish its reasonable assurance of safety finding. Alternative 2, would also compel applicants and licensees to develop their own methods acceptable to the NRC staff for meeting the subject regulations and deny the advantage of having access to methods readily acceptable by the NRC. Alternative 3 would be superior to Alternative 1 and 2 in that it would issue a new revision of RG 1.32 to include, where appropriate, updated codes/standards maintaining and or potentially enhancing safety, improving clarity, and increasing uniformity in review of applications and license amendments, etc.
With respect to NRC resources, Alternative 3 represents the greatest initial cost to the NRC, which is attributable to the costs associated with preparing and issuing the RG revision.
However, over the lifetime of the RG the total NRC cost of Alternative 3 is estimated to be less than the overall cost of Alternative 1 and 2 by reducing the cost related to additional staff resources and schedule impacts associated with the staff reviews and request for information (RAI) procedures.
With respect to applicants/licensees resources, Alternative 3 results in the least costs when compared to Alternative 1 and 2. Having a revised RG should reduce the need for RAIs and therefore the need for applicants and licensees to perform additional analyses to address them. Accordingly, costs to applicants and licensees associated with these additional activities are estimated to be lower with Alternative 3.
- 6.
Decision Rationale Based on this regulatory analysis, the NRC staff concludes that revision of RG 1.32 is warranted. The action will enhance the processes of compliance with regulation requirements for the design, operation, and testing of electric power systems in nuclear power plants by providing efficient and clear guidance and methods acceptable to the NRC staff. It could also lead to cost savings for the industry, especially regarding licensing and applications for standard plant design certifications and combined licenses.
Revising this RG to endorse portions of a consensus standard is consistent with the NRC policy of evaluating the latest versions of national consensus standards to determine their suitability for endorsement by RGs. This approach also will comply with the NRCs Management Directive 6.5, NRC Participation in the Development and Use of Consensus Standards (Agencywide Documentation Access and Management System Accession No. ML18073A164).
This is in accordance with Public Law 104-113, National Technology Transfer and Advancement Act of 1995.