ML24031A050
| ML24031A050 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 01/31/2024 |
| From: | NRC |
| To: | |
| References | |
| Download: ML24031A050 (3) | |
Text
From:
Cayetano Santos Sent:
Wednesday, January 31, 2024 8:46 AM To:
Vogtle PEmails
Subject:
FW: Erroneous Description of Tier 2* Change Process in Construction Lessons-Learned Report From: Joe Williams <govtmule57@me.com>
Sent: Monday, January 29, 2024 2:15 PM To: Andrea Veil <andrea.veil@nrc.gov>; Mike King <Michael.King2@nrc.gov>; James Gaslevic
<James.Gaslevic@nrc.gov>; Lauren Nist (She) <lauren.nist@nrc.gov>; Omar Lopez-Santiago
<Omar.Lopez-Santiago@nrc.gov>; Laura Dudes <Laura.Dudes@nrc.gov>; PDR Resource
<PDR.Resource@nrc.gov>
Subject:
[External_Sender] Erroneous Description of Tier 2* Change Process in Construction Lessons-Learned Report A recent post on NRCs Facebook page made me aware of the recent 10 CFR Part 52 Construction Lessons-Learned Report, ADAMS accession number ML23324A202, hereafter Lessons-Learned Report. When I looked at the report, I found that it does not accurately describe the change process for Tier 2* information for Vogtle Units 3 and 4. The report states that Departures from Tier 2*
information or the generic TS require a license amendment in accordance with 10 CFR 50.90, Application for amendment of license, construction permit, or early site permit. While this statement correctly describes the requirements of Part 52 and the AP1000 certified design which were applied to Vogtle Units 3 and 4 until late 2018, it is incorrect for the latter part of construction of Vogtle Units 3 and 4. In the fall of 2018, NRC approved a license amendment responding to the licensees License Amendment Request 17-037 that authorized use of the 50.59-like criteria for Tier 2* information. The licensees goal for this amendment was to eliminate the need for license amendments for most, if not all, subsequent Tier 2* changes for the Vogtle AP1000 units by using a change control process distinct from what is described in the AP1000 certified design rule. Therefore, the Lessons-Learned Report does not describe this fundamental change to a significant regulatory control in the midst of the construction of Vogtle Units 3 and 4, and so provides incomplete information for future reference by NRC staff, prospective applicants, and the public.
In addition, the Lessons-Learned Report discussion of the need to carefully select Tier 2* information is arguably incomplete. The report correctly states that The use of Tier 2* designations should be consistent with the approaches described in SECY-17-0075, Planned Improvements in Design Certification Tiered Information Designations, issued July 24, 2017 (ML16196A321) and SECY-19-0034, Improving Design Certification Content, issued April 2019 (ML19080A032). While I am unfamiliar with the latter SECY, I was the principal author and designated point of contact for SECY-17-0075. The discussion of the Tier 2* regulatory history in that paper stated that These documents clearly show that Tier 2* information is intended to have substantial safety significance, commensurate with information designated as Tier 1 [emphasis added]. The Lessons-Learned Report does not acknowledge the intended similar safety significance between Tier 2* and Tier 1 information.
During the AP1000 certified design review, the Standard Review Plan did not provide adequate guidance to applicants, or NRC staff and management regarding how information could be designated as Tier 2*.
The SRP did not clearly identify the intended similar safety significance of Tier 2* to Tier 1 information.
As I recall, the SRP said little on this topic beyond requiring that management approve Tier 2*
designations. This lack of clear guidance was certainly a factor in the overly-broad application of Tier 2*
information in the AP1000 certified design.
Similarly, the staff was not provided with adequate guidance for review of LAR 17-037. While the final safety evaluation considers the intended safety significance of Tier 2* information, that result came only at the end of a contentious review, as documented in a non-concurrence I prepared in cooperation with colleagues familiar with the regulatory processes and technical issues involved. Because clear guidance and acceptance criteria for the review had not been established, neither the licensees submittals or NRC staff requests for additional information addressed the intent that Tier 2* information have safety significance similar to Tier 1.
The Lessons-Learned Report includes Recommendation S.22 to Carefully select what information should be Tier 2* in future design certifications to reduce the number of unnecessary LARs for non-safety -significant changes. Accordingly, adequate guidance must be provided to applicants and NRC staff to provide clear basis for any information designated as Tier 2*. For example, if NRC staff believe an issue proposed for Tier 2 requires a degree of regulatory control beyond the 50.59-like process, they should describe how the safety significance of that topic is on par with Tier 1. In my view, applicants could then propose that issue be addressed via a Tier 2* designation, as the Tier 2*
regulatory history shows that the designation arose from the desire of reactor designers to limit the scope of information in Tier 1. I do not believe NRC staff should propose promotion of Tier 2 to Tier 2*,
as it is the applicants prerogative to propose what they consider to be a manageable scope, structure, and organization of information in the certified design, consistent with regulatory requirements.
In summary, the Lessons-Learned Report does not accurately describe regulatory control of Tier 2*
information applied during the latter part of construction of Vogtle Units 3 and 4, nor does it fully describe how the intended safety significance of that information should be addressed in future certified design reviews. Accordingly, it is my view that the report should be supplemented to address these deficiencies. NRC should update relevant guidance so all stakeholders have a clearer understanding of how Tier 2* should be employed.
Joe Williams
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FW Erroneous Description of Tier 2 Change Process in Construction Lessons-Learned Report Sent Date:
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