ML15344A294
| ML15344A294 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/10/2015 |
| From: | Craft W Dominion, Dominion Nuclear Connecticut |
| To: | Richard Guzman Plant Licensing Branch 1 |
| Guzman R | |
| References | |
| TAC MF7108 | |
| Download: ML15344A294 (10) | |
Text
Pre-Submittal Teleconference Millstone Power Station Unit 2 (MPS2)
License Amendment Request (LAR) for Charging System in Response to Confirmatory Order EA-13-188 December 10, 2015
Pg. 2 Agenda Purpose of LAR Scope of LAR AREVA Analysis for Long-Term IOPORV Application of Single Failure Criterion Applicable Regulatory Issue Schedule
Pg. 3 Purpose of LAR
Compliance Item #2:
By no later than February 15, 2016, DNC will submit a license amendment request to the NRC addressing the use of charging pumps in the analysis of the inadvertent opening of the PORVs.
- DNC has completed an analysis of the long-term response for FSAR Section 14.6.1, Inadvertent Opening of a Pressurized Water Reactor Pressurizer Pressure Relief Valve (IOPORV) with no credit for Charging flow
- LAR will include proposed changes to Technical Specification (TS) Section 3/4.5.2 and FSAR Chapter 14
- LAR meets regulatory criteria and will preserve health and safety of the public
Pg. 4 Scope of LAR
- LAR will include more than the analysis of the FSAR Section 14.6.1 IOPORV event required by the Confirmatory Order
- LAR will propose to remove Charging from TS 3/4.5.2, Emergency Core Cooling Systems
- Charging pumps appear in Surveillance Requirement (SR) 4.5.2.e as an ECCS subsystem with Operability requirements:
By verifying the delivered flow of each charging pump at the required discharge pressure is greater than or equal to the required flow when tested pursuant to Specification 4.0.5.
- LAR will demonstrate that Charging does not meet the four criteria in 10CFR50.36 for inclusion in the Technical Specifications
- Change to TS 3/4.5.2 Bases will be provided for information
Pg. 5 Scope of LAR (Continued)
- Proposed FSAR changes are based on the FSAR prior to the 2009 FSAR change made by DNC under 10 CFR 50.59
- Proposed FSAR change reflects the new long-term IOPORV analysis, which does not credit charging (discussed on next slide)
- Proposed change to FSAR Section 14.0.11 clarifies the application of single failure for MPS2
Pg. 6 AREVA Analysis for Long-Term IOPORV
- Analysis completed for long-term response to an IOPORV for MPS2
- Uses NRC-approved S-RELAP5 SBLOCA methodology in EMF-2328, Rev. 0, with Supplement 1
- Assumes open pressurizer safety valve which bounds two open PORVs
- Credits two HPSI pumps with no flow from charging pumps
- Results demonstrate no core uncovery
- LAR will include analysis description and plots of key results
- With this new analysis, flow from the charging pumps is not credited in any FSAR Chapter 14 safety analyses for event mitigation
Application of Single Failure Criterion
- Single failure criterion does not apply to Moderate Frequency events
- Consistent with MPS2 FSAR Section 14.0.11
- Consistent with NRC SRP (NUREG-0800) Chapter 15
- Postulating a single failure for the IOPORV event is a Small Break LOCA (FSAR Section 14.6.3) with acceptance criteria governed by 10 CFR 50.46
- MPS2 does not apply a single failure to the IOPORV event (with the exception of the reactor protection system)
Pg. 7
Pg. 8 Applicable Regulatory Issue
- Draft Revision 1 to RIS 2005-29 Anticipated Transients That Could Develop Into More Serious Events
- Draft Revision 1 to RIS 2005-29 provides regulatory positions on the IOPORV event that is addressed in the MPS2 LAR.
- Demonstration of no long term core uncovery demonstrates that the transient meets the non-escalation criteria
Pg. 9 Schedule
- Review schedule
- To maintain compliance with the Confirmatory Order, Operability Determination and Standing Order are in place for the Charging system and will remain in place until NRC makes a final determination on the LAR
Acronym List ANS American Nuclear Society CFR Code of Federal Regulations DNC Dominion Nuclear Connecticut ECCS Emergency Core Cooling System FSAR Final Safety Analysis Report IOPORV Inadvertent Opening of a Pressurizer Pressure Relief Valve LAR License Amendment Request MPS2 Millstone Power Station, Unit 2 PWR Pressurized Water Reactor RIS Regulatory Issue Summary SBLOCA Small Break Loss of Coolant Accident SR Surveillance Requirement SRP Standard Review Plan TS Technical Specifications Pg. 10