ML14310A022

Report Regarding Individual Plant Examination of External Events Supporting Information for Seismic Screening

ML14310A022
Person / Time
Site:	Millstone
Issue date:	11/13/2014
From:	Michael Balazik Japan Lessons-Learned Division
To:	Heacock D Dominion Nuclear Connecticut
Balazik M, NRR/JLD, 415-2856
References
TAC MF3968
Download: ML14310A022 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 13,2014 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.

lnnsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060

SUBJECT:

MILLSTONE POWER STATION, UNIT 2- REPORT OF REGULATORY AUDIT REGARDING INDIVIDUAL PLANT EXAMINATION OF EXTERNAL EVENTS SUPPORTING INFORMATION FOR SEISMIC SCREENING (TAC NO. MF3968)

Dear Mr. Heacock:

By letter dated March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued an information request, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident" (hereafter referred to as the 50.54(f) letter) (Agencywide Documents Access Management System (ADAMS) Package Accession No. ML12056A046), to all power reactor licensees and holders of construction permits. The 50.54(f) letter, in part, requested that licensees reevaluate the seismic hazards at their sites against present-day NRC requirements. For central and eastern United States sites, the 50.54(f) letter required licensees to submit a seismic hazard evaluation to the NRC by March 31, 2014.

By letter dated March 31, 2014 (ADAMS Accession No. ML14092A417), Dominion Nuclear Connecticut, Inc. (Dominion, the licensee) submitted its Seismic Hazard and Screening Report for Millstone Power Station, Units 2 and 3 (Millstone) to the NRC. Dominion concluded in the report that the Individual Plant Examination of External Events (IPEEE) is adequate for seismic screening purposes and that both Millstone, Units 2 and 3 screen out of conducting additional seismic risk evaluations.

The NRC endorsed industry guidance "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," provides the criteria used to determine if the licensee's IPEEE submittal is adequate to use for seismic screening purposes. If one or more of the criteria are not deemed adequate, the staff may still decide that the overall IPEEE analysis is adequate to support its use for seismic screening.

The NRC staff reviewed Dominion's submittal and determined that additional information was needed to determine the IPEEE adequacy for seismic screening of Millstone, Unit 2.

By letter dated July16, 2014 (ADAMS Accession No. ML14195A034), the NRC issued a request for additional information (RAI) to the licensee. Dominion submitted its RAI response by letter dated July 21, 2014 (ADAMS Accession No. ML14204A620). The letter identified that an audit may be needed to support this activity. Accordingly the NRC conducted an audit on

D. Heacock October 23, 2014, at the Nuclear Energy Institute facilities in Rockville, MD. The plan for this audit dated October 22, 2014, can be found in ADAMS under Accession No. ML14295A085.

The scope of this audit was limited to the information provided and referenced in Dominion's Seismic Hazard and Screening Report and response to the RAI. The purpose of this audit was to enable the NRC staff to come to a better understanding of the differences between original and reconstituted IPEEE supporting calculations performed on the Chill Water Surge Tank and Battery Rack DB1 and DB2. The information gained from this audit will inform the NRC's seismic screening determination for Millstone, Unit 2.

If you have any questions, please contact Michael Balazik at 301-415-2856 or by e-mail at Michaei.Balazik@ nrc.gov Sincerely, lazik, Project n ger Japan Lessons Learned Division Office of Nuclear Reactor Regulation Docket No. 50-336

Enclosure:

Audit Report cc w/encl: Distribution via Listserv

AUDIT REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING INDIVIDUAL PLANT EXAMINATION OF EXTERNAL EVENTS SUPPORTING INFORMATION FOR SEISMIC SCREENING DOMINION NUCLEAR CONNECTICUT, INC MILLSTONE POWER STATION, UNIT 2 DOCKET NO. 50-336 BACKGROUND On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued an information request, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident" (hereafter referred to as the 50.54(f) letter)

(Agencywide Documents Access Management System (ADAMS) Package Accession No. ML12056A046), to all power reactor licensees and holders of construction permits. The 50.54(f) letter, in part, requested that licensees reevaluate the seismic hazards at their sites against present-day NRC requirements. For central and eastern United States sites, the 50.54(f) letter required licensees to submit a seismic hazard evaluation to the NRC.

By letter dated March 31, 2014 (ADAMS Accession No. ML14092A417), Dominion Nuclear Connecticut, Inc. (Dominion, the licensee) submitted its Seismic Hazard and Screening Report for Millstone Power Station, Units 2 and 3 (Millstone) to the NRC. Dominion concluded in the report that the Individual Plant Examination of External Events (IPEEE) is adequate for seismic screening purposes and that both Millstone, Units 2 and 3 screen out of conducting additional seismic risk evaluations.

The NRC endorsed industry guidance "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," provides the criteria used to determine if the licensee's IPEEE submittal is adequate to use for seismic screening purposes. If one or more of the criteria are not deemed adequate, the staff may still decide that the overaiiiPEEE analysis is adequate to support its use for seismic screening.

The NRC staff reviewed Dominion's submittal and determined that additional information was needed to determine the IPEEE adequacy for seismic screening of Millstone, Unit 2. By letter dated July16, 2014 (ADAMS Accession No. ML14195A034), the NRC issued a request for additional information (RAI) to the licensee. Dominion submitted its RAI response by letter dated July 21, 2014 (ADAMS Accession No. ML14204A620).

Enclosure

The scope of this audit was limited to the information provided and referenced in Dominion's Seismic Hazard and Screening Report and response to the RAI. The purpose of the audit was to enable the NRC staff to come to a better understanding of the differences between original and reconstituted IPEEE supporting calculations performed on the Chilled Water Surge Tank and Battery Rack DB1 and DB2. The information gained from this audit will inform the NRC's seismic screening determination for Millstone Unit 2.

AUDIT ACTIVITIES The NRC audit team consisted of:

• Michael Balazik, Japan Lessons-Learned Division, Office of Nuclear Reactor Regulation

• Frankie Vega, Japan Lessons-Learned Division, Office of Nuclear Reactor Regulation

• Nilesh Chokshi, Division of Site Safety & Environmental Analysis, Office of New Reactors

• Kamal Manoly, Division of Engineering, Office of Nuclear Reactor Regulation

• Thomas Weaver, Division of Engineering, Office of Nuclear Regulatory Research

• Diane Jackson, Division of Site Safety & Environmental Analysis, Office of New Reactors

• Ricardo Rodriguez, Division of Site Safety & Environmental Analysis, Office of New Reactors The licensee supporting staff consisted of:

• Marc Hotchkiss, Dominion Nuclear

• Eric May, Dominion Nuclear

• Divakar Bhargava, Dominion Nuclear

• Joe Vasquez, Dominion Nuclear

The audit team reviewed the following types of information:

• Dominion 14-350_MPS2 RAI Response : "Response to Request for Additional Information Regarding Seismic Hazard and Screening Report for Seismic Recommendation 2.1, dated July 21, 2014

• ETE-CEM-2014-0001 Attachment 7, Resolution of Open Items from IPEEE Adequacy Review, Rev. 1

• 96- ENG -1380M2: "Qualification of Battery Racks DB1 and DB2 Anchorage Outlier Resolution for SQUG/A46, Rev. 2

• 97C2799-C-015 Rev.1: "Miscellaneous Seismic Capacity Calculations- excerpts for T98, dated December 31, 1997

• Drawing 25203-33027-00002: "Seis. Rstnts. For Bats. DB1 & DB2 (North) East & West Bat. RMS. EL. 14'-6", Rev. 1

• Drawing 25203-39020 Sh 7 and 11: " Rack Assembly Two-Step, 24 Cells LCU" Rev. 2

• C-73-267, Chilled Water Surge Tank Item T98, Rev. 5

• M-5957, Seismic Calculations Millstone, Unit 2 Nuclear, dated February 15, 1972

• MMOD M2-96568: "Modification of Station Batteries 201 A And 201 B Rack Anchorage-excerpt, Rev. 0

• S&A 93C2799- C- 007: "Seismic Capacity of DB1 Battery Rack", dated October 30, 1995

• DM2-S-0698-96, Battery Racks DB1 & DB2 Anchorage Modification to Resolve USIA-46 Outlier, dated July 23, 1996

AUDIT

SUMMARY

The audit team performed an independent review of the calculation packages referenced above.

The team's observations were discussed with the licensee to further understand the licensee's actions in demonstrating the adequacy of their IPEEE program to meet the SPID screening criteria. The information gained from this audit will assist the NRC in determining the seismic screening for Millstone, Unit 2.

Discussions with the licensee led to an increased level of clarity regarding the licensee's IPEEE program. Specifically, the staff reviewed Millstone's updated High Confidence Low Probability of Failure (HCLPF) capacity calculations for two components: the chilled water surge tank and the battery racks DB1 and DB2. As part of the NRC's IPEEE screening review, the staff asked the licensee for additional clarification regarding the HCLPF for these two components. As part of the response to the staff's RAI, the licensee reconstituted these calculations since they were unable to locate them as part of the originaiiPEEE documentation. During the audit these calculations, along with supporting documentation, were reviewed by the staff in order to confirm the licensee's conclusion which assigned HCLPF values of .25g or higher for the two components. Based on a detailed staff review and after discussions with the licensee, the staff was able to confirm that the stated conclusions were acceptable. The staff was also able to understand the differences between the original and reconstituted IPEEE calculations performed for these two components. In addition to the calculation review, the staff confirmed that certain modifications were made, as credited in the seismic hazard and screening report.

By discussing these specific topics in depth with the licensee and reviewing the documentation, the team was able to meet the objectives of the audit and has a better understanding of the licensee's IPEEE program with regards to meeting the SPID screening criteria and has sufficient information to address the issues identified in the audit plan.

CONCLUSION The staff was able to obtain the needed information in order to make a conclusion on whether the IPEEE is adequate to support its use for seismic screening for Millstone, Unit 2. No further information will be requested.

D. Heacock October 23, 2014, at the Nuclear Energy Institute facilities in Rockville, MD. The plan for this audit dated October 22, 2014, can be found in ADAMS under Accession No. ML14295A085.

The scope of this audit was limited to the information provided and referenced in Dominion's Seismic Hazard and Screening Report and response to the RAI. The purpose of this audit was to enable the NRC staff to come to a better understanding of the differences between original and reconstituted IPEEE supporting calculations performed on the Chill Water Surge Tank and Battery Rack DB1 and DB2. The information gained from this audit will inform the NRC's seismic screening determination for Millstone Unit 2.

If you have any questions, please contact Nicholas Michael Balazik at 301-415-2856 or bye-mail at Michaei.Balazik@nrc.gov Sincerely, IRA/

Michael F. Balazik, Project Manager Japan Lessons Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-245

Enclosure:

Audit Report cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC MBalazik, NRR JHMB R/F NDiFrancesco, NRR RidsNrrDorllpl1-1 Resource FVega, NRR RidsNrrPMMillstone Resource DJackson, NRO RidsNrrLASLent Resource SWhaley, NRR ADAMS Accession Number* ML14310A022 OFFICE NRR/JLD/JHMB/PM NRR/JLD/JHMB/PE NRR/JLD/JHMB/BC NAME MBalazik FVega SWhaley DATE 11/10/14 11/10/14 11/12/14 OFFICE NRO/DSENRGS1 NRR/JLD/JHMB/LA NRR/JLD/JHMB/PM NAME DJackson SLent MBalazik DATE 11/10/14 11/10/14 11/13/14 OFFICIAL RECORD COPY