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 Tes ting of Safety-Related Diesel Generators in Nuclear Pow er Plants, issued in March 200 7, establishes the NRCs position for an acceptable approach for satisfying the Co mmissions regulations on the design, qualification, and periodic testing of diesel ge nerators used as onsite electric power systems. RG 1.9, Rev 4 endorses with clarificati ons and exceptions, Institute of Electrical and Electronics Engineers (IEEE) Standa rd 387, IEEE Standard Criteria for Diesel-Generator Units Applied as Standby Power Su pplies for Nuclear Power Generating Stations (IEEE Std. 387-1995). Since the publ ication of RG 1.9, Rev.

4, IEEE Std. 387 has been revised and was published in 2017. IE EE 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 per formance d) Expanding factory production testing and site testing criter ia e) Updating specific surveillance requirements f) Providing acceptable method for reliability program elements (Annex D) g) Emergency diesel generators with dedicated battery control p ower 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 i s 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 gu idance 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) fo r 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 th e Advisory Committee and Reactor Safeguards (ML22061A199) the staff reasse ssed 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 licens ing and inspection activities over the next several years?

If the guidance is not updated, applications in operating react ors 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 y ear (e.g., extension of allowed outage time, draft TSTF-599, "Eliminate Periodic Survei llance Test of Simultaneous Start of Redundant Diesel Generators, (ML23222A26 1), 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 re lated activities. No contractor support is anticipated.

4. Based on the answers to the questions above, what is the sta ff 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 issu es 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 inte rnational standard), once it is published.

It is intended that the revised Proposed Revision 5 to RG 1.9 w ill 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 chan ge.