ML19122A256

SPRA Revised PRA Question 3

ML19122A256
Person / Time
Site:	Oconee
Issue date:	05/02/2019
From:	Peter Bamford Beyond-Design-Basis Management Branch
To:	Grzeck L Duke Energy Carolinas
Peter Bamford 301-415-2833
References
EPID L-2018-JLD-0173
Download: ML19122A256 (2)

Text

From: Bamford, Peter To: Grzeck, Lee Cc: Todd, Laura Frances

Subject:

Oconee SPRA Questions Date: Thursday, May 02, 2019 8:35:00 AM Attachments: Revised Question 3.pdf Lee, thanks for coordinating the call yesterday from the Duke side. Per the phone call action items, please find a revised question 3 (changes made to both 3a and 3b) that hopefully clarifies the information we are looking for. You should use this version of Question 3 in place of the one I originally sent to you on April 22, 2019 (ADAMS Accession No. ML19113A168).

Thanks.

Peter Bamford Senior Project Manager Nuclear Regulatory Commission (NRR/DLP/PBMB)

(301)415-2833

Question 3 - Topic 14: Peer Review of the Seismic PRA, Accounting for NEI 12-13 (SPID Section 6.7)

The dispositions to F&O 25-14 and 26-2, related to SRs C-SPR-B1 and C-SPR-A1, respectively, regarding applicability of the accident sequences, system logic, and initiating events in the internal events PRA model to the SPRA, state that the majority of the items did not require updating the SPRA model. However, for the remaining items, the disposition states that they were considered for inclusion. It is unclear to the NRC staff how the systematic review was performed to identify the items for inclusion in the SPRA. The rationale for exclusion of any of the identified items from the SPRA used for this submittal is also unclear. In light of these observations:

a. Describe the systematic review performed to identify the internal events modeling assumptions applicable to the SPRA and disposition the cited F&Os.

b. As described in the introductory paragraph to this question, it is unclear if items were excluded from the SPRA. For any items that were excluded, provide justification, such as a sensitivity study, that the exclusion of these items does not impact the decisions for this submittal (i.e., identifying potential substantial safety enhancements using importance measures from the SPRA).