ML19337B732
| ML19337B732 | |
| Person / Time | |
|---|---|
| Issue date: | 12/04/2019 |
| From: | Walter Kirchner Advisory Committee on Reactor Safeguards |
| To: | Riccardella P Advisory Committee on Reactor Safeguards |
| Snodderly, M, ACRS | |
| Shared Package | |
| ML19337B671 | List: |
| References | |
| Download: ML19337B732 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS WASHINGTON, DC 20555 - 0001 December 04, 2019 MEMORANDUM TO: Peter Riccardella, Chairman Advisory Committee on Reactor Safeguards FROM: Walter L. Kirchner, Member /RA/
Advisory Committee on Reactor Safeguards
SUBJECT:
PROPOSED RECOMMENDATION FOR ACRS REVIEW OF NUSCALE POWER, LLC, DESIGN CERTIFICATION APPLICATION - SAFETY EVALUATION WITH NO OPEN ITEMS FOR CHAPTER 5, REACTOR COOLANT SYSTEM AND CONNECTING SYSTEMS In response to the Committees request, I have reviewed the NRC staffs safety evaluation report (SER) with no open items for Chapter 5, Reactor Coolant System and Connecting Systems, dated October 10, 2019 (ML19284A372). The following is my recommended course of action concerning further review of this chapter of the design certification application and the staffs associated safety evaluation.
SER Phase 4 Summary Chapter 5 of the SER documents the staffs review of Revision 2 of Chapter 5, Reactor Coolant System and Connecting Systems, of the NuScale Design Certification Application, Part 2, Tier 2 Final Safety Analysis Report (ML18310A326).
The reactor coolant system (RCS) provides for circulation of the primary coolant. The applicants design relies on natural circulation flow for the primary coolant and does not include reactor coolant pumps or an external piping system. The RCS is a subsystem of the NuScale Power Module. The RCS includes the reactor vessel and integral pressurizer, the reactor vessel internals, the reactor safety valves, two helical-coil steam generators integrated into the reactor vessel, RCS piping inside the containment vessel (RCS injection and discharge, pressurizer spray supply, and reactor vessel high-point degasification lines), pressurizer controls, and RCS instruments and cables.
The staff has confirmed that proposed changes for confirmatory items described in the Phase 2 SER have been incorporated in the design certification application, Revision 3, and are closed.
In addition, all open items identified during Phase 2 of the review have been satisfactorily closed. A confirmatory item related to the decay heat removal system (DHRS) performance analysis remains open as described below.
P. Riccardella Applicable Concerns from ACRS Phase 3 Letter Report The Committee identified that Chapter 15 accident analysis issues must be reviewed and resolved to demonstrate acceptability of the DHRS design in satisfying General Design Criteria 34 and 35. The applicant has committed to demonstrate predicted capability of the DHRS as part of start-up testing for the first plant to go into operation.
Staff Response to ACRS Letter Report The staff agreed with the ACRS position regarding the above accident analysis issues (Conclusion and Recommendation #1 of our letter report dated May 30, 2019). The SER identifies a confirmatory item related to completion of the staffs safety evaluation for NuScale Topical Report TR-0516-49416-P, Non-Loss-of-Coolant Accident Evaluation Model. The safety evaluation for this topical report is scheduled for ACRS review in 2020.
Open Items from Phase 3 Requiring Further ACRS Review The Committee will review the staffs SER for NuScale Topical Report TR-0516-49416-P (and any subsequent related issues in Chapter 15 accident analyses).
Recommendation As lead reviewer for NuScale Chapter 5, I recommend that the Committee not perform any additional Phase 5 review of this chapter, contingent on the Committees future review of TR-0516-49416-P as regards non-LOCA accident analyses, and in particular decay heat removal system performance. Steam generator performance will be addressed as a focus area topic.
P. Riccardella December 04, 2019
SUBJECT:
PROPOSED RECOMMENDATION FOR ACRS REVIEW OF NUSCALE POWER, LLC, DESIGN CERTIFICATION APPLICATION - SAFETY EVALUATION WITH NO OPEN ITEMS FOR CHAPTER 5, REACTOR COOLANT SYSTEM AND CONNECTING SYSTEMS Package No.: ML19337B671 Accession No: ML19337B732 Publicly Available Y Sensitive N Viewing Rights: NRC Users or ACRS Only or See Restricted distribution *via email OFFICE ACRS/TSB SUNSI Review ACRS/TSB ACRS NAME MSnodderly MSnodderly LBurkhart WKirchner (LBurkhart for)
DATE 12/3/2019 12/3/2019 12/4/2019 12/4/2019 OFFICIAL RECORD COPY