ML13247A751
| ML13247A751 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/04/2013 |
| From: | James Kim Division of Operating Reactor Licensing |
| To: | Bartron W Dominion Nuclear Connecticut |
| Kim J, NRR/DORL, 301-415-4125 | |
| References | |
| TAC MF1779 | |
| Download: ML13247A751 (2) | |
Text
From:
Kim, James Sent:
Wednesday, September 04, 2013 4:09 PM To:
William D Bartron (william.d.bartron@dom.com)
Cc:
MaryLou L Calderone (marylou.l.calderone@dom.com); Wanda D Craft (wanda.d.craft@dom.com)
Subject:
MPS2 UHS - NRC RAI (September 4, 2013)
- Bill, Please provide the responses to Millstone 2 Ultimate Heat Sink RAI questions shown below.
- Thanks, Jim Kim REQUEST FOR ADDITIONAL INFORMATION By CONTAINMENT AND VENTILATION BRANCH MILLSTONE 2 TECHNICAL SPECIFICATION CHANGES REGARDING ULTIMATE HEAT SINK TEMPERATURE INCREASE DOCKET NO. 50-336 By letter dated May 3, 2013, (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML13133A033), Dominion Nuclear Connecticut, Inc. (DNC, the licensee) submitted a License Amendment Request (LAR) for Millstone Power Station Unit 2 (MPS2). The proposed amendment would modify Technical Specification (TS) 3/4.7.11, Ultimate Heat Sink, by increasing the current Ultimate Heat Sink (UHS) water temperature from 75oF to 80oF.
The Containment and Ventilation Branch (SCVB) staff has reviewed the licensees information that supports the proposed amendment and would like to request responses to the following issues to complete its review:
SCVB-RAI-1 Section 5.10, second paragraph of the LAR mentions about MPS2 LOCA and MSLB containment response analysis using the revised Mass and Energy (M&E) release information and Ultimate Heat Sink (UHS) temperature of 80oF.
(a) Describe the basis and reasons for the revision in the M&E release information provided by Westinghouse.
(b) Please provide the results of the revised containment peak pressure licensing basis analysis. Please describe the impact that an increase in the UHS temperature from the current TS limit to 80ºF has on the containment peak pressure, containment peak gas temperature for EQ, and peak containment liner temperature.
SCVB-RAI-2
Please describe the impact that an increase in the UHS temperature from the current TS limit to 80ºF has on the maximum sump water temperature and available Net Positive Suction Head (NPSH) of the ECCS and containment spray pumps post-LOCA following the Sump Recirculation Actuation Signal (SRAS), and describe how the NPSH analysis complies with Safety Guide 1 (Regulatory Guide 1.1) as described in FSAR Sections 6.2.3.1 and 6.4.4.1.
SCVB-RAI-3 NUREG-0800, Standard Review Plan (SRP) 6.2.1.5 describes the minimum containment pressure analysis for emergency core cooling system (ECCS) performance capability.
Regulatory Guide (RG) 1.157, Section 3.12.1 provides guidance for calculating the containment pressure response used for evaluating cooling effectiveness during the post-blowdown phase of a LOCA. The RG states that the containment pressure should be calculated by including the effects of containment heat sinks and operation of all pressure-reducing equipment assumed to be available. Using the above guidance please describe the impact of the changes in M&E input on the minimum containment pressure analyses for ECCS performance.
SCVB-RAI-4 Please confirm that in the 10 CFR 50.59 changes implemented, the requirements of General Design Criterion (GDC) 16, 38, and 50 of 10 CFR 50 Appendix A are met.