ML20149K681
| ML20149K681 | |
| Person / Time | |
|---|---|
| Issue date: | 05/27/2020 |
| From: | Michael Snodderly Advisory Committee on Reactor Safeguards |
| To: | Walter Kirchner, Jose March-Leuba Advisory Committee on Reactor Safeguards |
| Snodderly M | |
| References | |
| Download: ML20149K681 (2) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, DC 20555 - 0001 May 27, 2020 MEMORANDUM TO:
Walter Kirchner, Chairman Jose March-Leuba, Member NuScale Subcommittee FROM:
Mike Snodderly, Senior Staff Engineer /RA/
Technical Support Branch Advisory Committee on Reactor Safeguards
SUBJECT:
ANALYSIS OF NRR RESPONSE TO ACRS LETTER ON NUSCALE CHAPTER 15: OPEN ITEM CLOSURE AND AREA OF FOCUS REVIEWS - RETURN TO CRITICALITY AND BORON DISTRIBUTION Attached is a copy of the January 27, 2020, Office of Nuclear Reactor Regulation (NRR) response to the May 22, 2020, ACRS letter on NuScale Chapter 15: Open Item Closure and Area of Focus Reviews - Return to Criticality and Boron Distribution. A copy of the Committees letter is also attached.
Committee Letter:
In its April 29, 2020 letter:
The Committee concurred with the staffs conclusions in Chapter 15 of their Advanced Safety Evaluation Report: all open items, including those unresolved from the earlier safety evaluation, have been resolved. However, a new issue related to boron redistribution remains open.
With regard to return to criticality, the Committee concluded that the low risk of event sequences associated with return to criticality makes the General Design Criterion (GDC) 27 exemption acceptable.
The Committee concluded that the boron redistribution issue remains open and they acknowledged that the applicant and the staff are working on its resolution. The Committee stated that they would review the final staff evaluation.
EDO Response:
The NRC staff stated that they appreciated the ACRSs review and recommendation and they will continue to work towards issuing a Chapter 15 Phase 6 safety evaluation report upon evaluating the additional changes resulting from the boron redistribution issue. The staff stated that they understand the Committees concerns and will continue to coordinate with the Committee with follow-up briefings that have been scheduled (i.e., NuScale will brief ACRS on the recent design changes regarding boron redistribution on June 3, 2020 and NRC staff will brief ACRS in July 2020).
Analysis:
I recommend that the Committee accept the staffs response and that the Committee address its concerns during meetings with the staff and NuScale on June 3-4, 2020 and July 8-9, 2020.