ML24040A098

Rev 4 Periodic Review

ML24040A098
Person / Time
Issue date:	03/06/2024
From:	Sheila Ray NRC/NRR/DEX/EEEB
To:
Shared Package
ML24040A094	List: ML24040A098
References
RG-1.009, Rev 4
Download: ML24040A098 (2)

Text

Regulatory Guide Number:

1.9, Revision 4

Title:

Application and Testing of Safety-Related Diesel Generators in Nuclear Power Plants 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)?

Regulatory Guide 1.9, Revision 4 (Rev. 4), Application and Testing of Safety-Related Diesel Generators in Nuclear Power Plants, issued in March 2007, establishes the NRCs position for an acceptable approach for satisfying the Commissions regulations on the design, qualification, and periodic testing of diesel generators used as onsite electric power systems. RG 1.9, Rev 4 endorses with clarifications and exceptions, Institute of Electrical and Electronics Engineers (IEEE) Standard 387, IEEE Standard Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations (IEEE Std. 387-1995). Since the publication of RG 1.9, Rev.

4, IEEE Std. 387 has been revised and was published in 2017. IEEE Std. 387-2017 provides additional detail on the following:

a) Defining specific qualification requirements b) Clarifying scope and scope diagram c) Providing requirements for no-load and light-load operation, since extended operation under these conditions may be detrimental to unit performance d) Expanding factory production testing and site testing criteria e) Updating specific surveillance requirements f) Providing acceptable method for reliability program elements (Annex D) g) Emergency diesel generators with dedicated battery control power system Furthermore, IEEE Std. 387 is currently in the process of being revised to be a joint logo international standard with the International Electrotechnical Commission (IEC), and additional new information is expected when the next revision is published this year. In addition, since the publication of RG 1.9, Rev. 4, the NRC has reviewed numerous applications under 10 CFR Part 52 and an increase in operating experience notices for the subject. As such, it is the staffs intent to update the guidance to evaluate and potentially, incorporate new information from IEEE Std. 387 and include 10 CFR Part 52 and other nuclear facilities in the scope.

In January 2021, the staff pursued proposed Revision 5 to RG 1.9 and issued draft regulatory guide (DG)-1303 (ADAMS Accession No. ML14281A071) for public comment Federal Register notice 86 FR 5267. However, as noted on March 17, 2022, in the Memorandum from the Office of Nuclear Regulatory Research to the Advisory Committee and Reactor Safeguards (ML22061A199) the staff reassessed the resources needed to complete the proposed revision to RG 1.9 and decided to defer work on the RG update at that time.

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?

If the guidance is not updated, applications in operating reactors and new reactors could be affected, considering 10 CFR Part 52 is not fully addressed in the current guidance and the new information from IEEE Std. 387 is not evaluated. For operating reactors, the staff anticipates approximately 5-10 licensing activities per year (e.g., extension of allowed outage time, draft TSTF-599, "Eliminate Periodic Surveillance Test of Simultaneous Start of Redundant Diesel Generators, (ML23222A261), etc. involve the use of RG 1.9, Rev. 4. For new reactors, the staff anticipates the submission of 3-5 applications for review in the near future that may utilize the diesel generators in the design.

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?

NRC staff requires approximately 0.75 FTE to complete update related activities. No contractor support is anticipated.

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 revise Proposed Revision 5 to RG 1.9, which endorses, with supplements and clarifications, IEEE Std. 387-2017, to consider additional changes from the upcoming revision of the standard (i.e., to joint logo international standard), once it is published.

It is intended that the revised Proposed Revision 5 to RG 1.9 will be made available by the end of the 2025 fiscal year for public comment.

NOTE: This review was conducted in February 2024 and reflects the staffs plans as of that date. These plans are tentative and subject to change.