ML19194A001

Memo E-mail to File - Summary of June 3, 2019, Meeting with Dominion to Discuss Proposed License Amendment Request to Extend Integrated Leak Rate Test Interval

ML19194A001
Person / Time
Site:	Millstone
Issue date:	07/12/2019
From:	Richard G Plant Licensing Branch 1
To:	James Danna Plant Licensing Branch 1
Guzman R
References
EPID L-2019-LRM-0026
Download: ML19194A001 (4)

Text

From: Guzman, Richard To: Danna, James

Subject:

Memo E-mail to File - Summary of June 3, 2019, Meeting with Dominion to Discuss Proposed LAR to Extend Integrated Leak Rate Test Interval Date: Friday, July 12, 2019 6:00:21 AM

Jim, For your information, shown below is a summary of the June 3, 2019, Category 1 public meeting with Dominion Energy Nuclear Connecticut, Inc. to discuss the licensees proposed license amendment request to extend the integrated leak rate test interval for Millstone Power Station, Unit No. 3. This e-mail will be added to ADAMS as an official agency record and Listservd. Please contact me if you have any questions regarding this meeting.

Rich Guzman Sr. PM, Division Operator Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov CATEGORY 1 PUBLIC MEETING WITH DOMINION ENERGY NUCLEAR CONNECTICUT, INC. (DENC),

TO DISCUSS PROPOSED LICENSE AMENDMENT REQUEST TO EXTEND THE INTEGRATED LEAK RATE TEST INTERVAL MILLSTONE POWER STATION, UNIT NO. 3 PRE-APPLICATION MEETING MEETING

SUMMARY

JUNE 3, 2019 DOCKET NO. 50-423 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) held a public meeting via teleconference call on June 3, 2019, to discuss the licensees planned license amendment request to extend the integrated leak rate test (ILRT) interval from 10 years to 15 years for the Millstone Power Station, Unit No. 3 (MPS3). The licensees meeting slides are available in Agencywide Documents Access and Management System (ADAMS) at Accession No. ML19143A472. The licensees presentation is summarized as follows:

Overview of Proposed LAR Dominion Energy proposes a License Amendment Request (LAR) for MPS3, which will revise Technical Specification (TS) 6.8.4.f, "Containment Leakage Rate Testing Program,"

by replacing the reference to Regulatory Guide (RG) 1.163 (September 1995) with a reference to Nuclear Energy Institute (NEI) topical report NEI 94-01, Revision 3-A. The LAR will also request additional wording to impose the limitations and conditions specified in NEI 94-01, Revision 2-A, as the implementing documents used to develop the MPS3

performance-based leakage testing program in accordance with 10 CFR 50, Appendix J, Option B. These changes would allow DENC to extend the Type A primary containment ILRT interval from 10 to 15 years and the Type C local leak rate test interval from 60 to 75 months for MPS3, and incorporates the regulatory positions stated in RG 1.163. The LAR would include a confirmatory risk impact assessment performed using the template contained in Electric Power Research Institute (EPRI) Report No. 1009325, Revision 2, and a probabilistic risk assessment (PRA) quality evaluation against the technical adequacy requirements of RG 1.200 Rev 2. As technical justification for the proposed changes, the licensee provided an overview of its testing history and inspections, PRA background and scope, and PRA quality.

MPS3 Testing History and Inspections The licensee stated that they would provide in their LAR a summary of the last three containment leak rate test program results (i.e., from 2011, 1998, and 1993) which demonstrate that measured leak rates meet the applicable TS limits and/or Appendix J criterion with margin. The licensee indicated the one exception was a failed (as-found)

Type A test due to leakage from a containment purge valve as described in Licensee Event Report (LER) 9601200. The licensee further stated that it performed the containment inspections per the IWE/IWL program and they have not observed any active degradation mechanisms.

MPS3 PRA Background and Scope The licensee prepared a confirmatory risk impact assessment in accordance with the methodology described in EPRI Report No. 1009325, Revision 2 for ILRT extensions. The MPS3 assessment confirmed the general findings of NUREG1493 (PerformanceBased Containment LeakTest Program) on a plant specific basis, considering severe accidents for MPS3. The conclusion from the confirmatory risk assessment was that increasing the ILRT interval to 15 years is considered to be an insignificant change in risk since it represents a small change to the MPS3 risk profile. The scope of MPS3 PRA model includes internal events and internal flood hazards.

MPS3 PRA Quality The licensee recently contracted with Westinghouse to perform a focusedscope peer review of the MPS3 PRA to determine compliance with Addendum A of the ASME/ANS PRA Standard and RG 1.200, Revision 2. This review, when combined with a previous focused scope peer review, resulted in a complete review of the MPS3 Internal Event and Internal Flood PRA model against the full scope of ASME/ANS RASa2009/RG 1.200 Rev. 2, technical requirements.

As a result of the focused scope peer review, the MPS3 PRA model has 106 Facts and Observations (F&Os) of finding significance that are considered open against the model.

Each finding has been assessed and dispositioned which the licensee plans to include as a table in the LAR. The licensee explained that each finding was dispositioned using either a qualitative assessment technique or it was incorporated into a quantitative sensitivity analysis which assessed the cumulative impact of PRA findings, uncertainties and pending changes to the PRA model. Finally, DENC presented the basis for determining the MPS3

PRA model, including the 106 findings, to be acceptable for ILRT surveillance application as (1) the ILRT risk assessment methodology employs a number of simplifying assumptions which apply conservative bias to the evaluation; (2) the subject of the findings do not adversely impact the ability of the MPS3 model to support this application; and (3) the sensitivity analysis demonstrates that the ILRT risk analysis has very low sensitivity to the cumulative impact of the peer review findings.

Schedule The licensee stated their planned submittal is on track and projected for submission by the end of July 2019. DENC intends to request an approval date of July 2020.

Conclusion DENC completed its presentation with no open/unanswered questions from the staff and summarized the conclusions as follows: (1) the licensee is proposing to adopt the guidance of NEI 9401, Revision 3A, and the limitations and conditions specified in NEI 9401, Rev.

2A, for use in the MPS3 10 CFR 50, Appendix J testing program; (2) based on the previous ILRT tests conducted at MPS3, the licensee has concluded that extension of the containment Type A (ILRT) interval from 10 to 15 years and the Type C local leak rate test from 60 months to 75 months represent minimal risks to increased leakage; and (3) the findings of the MPS3 risk assessment confirm, on a plant-specific basis, that extending the Type A (ILRT) interval from 10 to 15 years results in a small change to the MPS3 risk profile.

No decisions were made regarding the acceptability of the licensees proposed submittal.

There were no members of the public in attendance. To date, no public meeting feedback forms have been submitted through the NRC public meeting feedback system.

LIST OF ATTENDEES JUNE 3, 2019, CATEGORY 1 PUBLIC MEETING WITH DOMINION ENERGY NUCLEAR CONNECTICUT, INC. (DENC),

TO DISCUSS PROPOSED LICENSE AMENDMENT REQUEST TO EXTEND THE INTEGRATED LEAK RATE TEST INTERVAL MILLSTONE POWER STATION, UNIT NO. 3 DOCKET NO. 50-423 ATTENDEE ORGANIZATION Richard Guzman U.S. Nuclear Regulatory Commission (NRC)

Jerome Bettle NRC Dan Hoang NRC Jerry Dozier NRC Josh Wilson NRC Lauren Lopez DENC Creighton Adsit DENC Fred Cietek DENC Jeff Langan DENC

Craig Sly DENC Shayan Sinha DENC Marylou Calderone DENC