ML15279A450
| ML15279A450 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/09/2015 |
| From: | Nicholas Difrancesco Japan Lessons-Learned Division |
| To: | William Gideon Duke Energy Progress |
| Wyman S, 415-3041, O-13C05M | |
| References | |
| TAC MF3824, TAC MF3825 | |
| Download: ML15279A450 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 9, 2015 Mr. William R. Gideon Brunswick Steam Electric Plant Vice President Brunswick Steam Electric Plant P.O. Box 10429 Southport, NC 28461
SUBJECT:
REPORT FOR THE AUDIT OF DUKE ENERGY PROGRESS, INC.'S. INTERIM EVALUATION ASSOCIATED WITH REEVALUATED SEISMIC HAZARD IMPLEMENTING NEAR-TERM TASK FORCE RECOMMENDATION 2.1 -
SEISMIC FOR: BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 (TAC NOS. MF3824 AND MF3825)
Dear Mr. Gideon:
By letter dated September 8, 2015 (Agencywide Documents Ai:cess and Management System (ADAMS) Accession No. ML15231A022), the U.S. Nuclear Regulatory Commission (NRC) informed you of the staff's plan to conduct a regulatory audit of Duke Energy Progress, lnc.'s.
(Duke, the licensee) interim evaluation, also referred to as the Expedited Seismic Evaluation Process (ESEP), associated with reevaluated seismic hazard implementing Near-Term Task Force (NTTF) Recommendation 2.1 Seismic for Brunswick Steam Electric Plant, Units 1 and 2 (Brunswick).
The audit was conducted in Rockville, MD via e-portal access provided by Duke. This audit was performed consistent with NRC Office of Nuclear Reactor Regulation, Office Instruction LIC-111, "Regulatory Audits," dated December 29, 2008 (ADAMS Accession No. ML082900195).
The NRC staff developed this report to document its audit observations and conclusions.
The audit provided the NRC staff with a better understanding of the ESEP interim evaluations associated with NTTF Recommendation 2.1 "Seismic" and al:owed the NRC staff to evaluate Duke's implementation of the endorsed Electric Power Researc.h Institute (EPRI) guidance 1 , as described by Brunswick.
1 The EPRI ESEP guidance document can be founc i'l AO.AMS under Accession No. ML13102A142.
W. Gideon The audit supported the NRC staff review of the Brunswick ESEP report and related NRC staff requests for additional information. The NRC staff has completed its review based in part on information documented in this audit report. The NRC staff anticipates no further requests for additional information related to the Brunswick ESEP report. Additional information related to the audit is provided below.
If you have any questions, please contact me at (301) 415-1115 or by e-mail at Nicholas.Difrancesco@nrc.gov.
icholas J. rancesco, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation
Enclosure:
Audit Report cc w/encl: Distribution via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 AUDIT REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION FOR THE AUDIT OF DUKE ENERGY PROGRESS, INC.'S.
INTERIM EVALUATION ASSOCIATED WITH REEVALUATED SEISMIC HAZARD IMPLEMENTING NEAR-TERM TASK FORCE RECOMMENDATION 2.1- SEISMIC BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 BACKGROUND AND AUDIT BASIS On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued a request for information pursuant to Title 10 of the Code of Federal Regulations Part 50, Section 50.54(f)
(hereafter referred to as the 50.54(f) letter)(Agencywide Documents Access and Management System (ADAMS) Accession No. ML12053A340. The purpose of that request was to gather information concerning, in part, the seismic hazards at operating reactor sites to enable the NRC staff to determine whether your license should be modified, suspended, or revoked.
The NRC staff is conducting regulatory audits on the licensee's interim evaluation to determine if the information provided met the intent of the Expedited Seismic Evaluation Process (ESEP) guidance and if licensees responded appropriately to Requested Information Item (6) in to the 50.54(f) letter.
By letter dated December 18, 20142 , to the NRC, Duke Energy Progress, Inc. (Duke, the licensee) submitted for NRC review its ESEP evaluations for Brunswick Steam Electric Plant, Units 1 and 2 (Brunswick). The NRC staff issued a request for additional information (RAI) on June 23, 2015 to gain a better understanding of the information provided in the ESEP reports.
Specific documents that were reviewed by the staff during the audit are provided below.
REGULATORY AUDIT SCOPE AND METHODOLOGY The scope of this audit was limited to the information provided and referenced in the ESEP report and in responses to the NRC staff RAls. The purpose of this audit was to enable the NRC staff to determine if the information provided as part of the ESEP submittal met the intent of the guidance and if the licensee responded appropriately to Requested Information Item (6) in to the 50.54(f).
2 The December 18, 2014 letter can be found under ADAMS Accession No. ML15005A074.
Enclosure
REFERENCES:
Brunswick ESEP Report, December 18, 2014 (ADAMS Accession No. ML15005A074)
The NRC Staff Requests for Additional Information, Email from Stephen Wyman, NRC to Bill Murray, Duke June 23, 2015 (ADAMS Accession No. ML15224B251)
NRC AUDIT TEAM:
Title Team Member Team Leader, NRR/JLD Nicholas DiFrancesco Branch Chief, NRO/DSEA Diane Jackson Technical Lead (NRO/DSEA) Nilesh Chokshi Technical Support (NRC/NRR) Kamal Manolv Technical Support (NRC/NRO) Jim Xu Technical Support (NRC) Dan HuanQ Technical Support (NRC) Tuan Le Technical Support (NRC) Georae Wana Technical Support (NRC) Ian Tsena Technical Support (NRC/NRO) Sunwoo Park Technical Support (NRC) Robert Hsu Technical Support (NRC/NRO) Ricardo Rodriauez Technical Support (BNL/Consultant) Nick Simes Technical Support (BNL/Consultant) Richard Morante Technical Support (BNL/Consultant) Joe Braverman LOGISTICS:
Items were reviewed via the Brunswick e-portal. No further requests for information were made.
STAFF AUDIT
SUMMARY
Two Questions Related to Section V of the Checklist As a result of the NRC review of the Brunswick ESEP report, two questions were identified which relate to the development of the in-structure response spectra (ISRS) and high confidence of low probability of failure (HCLPF) values of components. The two questions, Brunswick responses, and staff evaluations are given below.
- 1. Section 5.2 of the ESEP report states: "The ISRS for the ESEP were developed by linearly scaling the existing Brunswick ISRS by the ESEP specified maximum ratio of two times the safe shutdown earthquake (SSE). For the Containment, the A-46 response spectra were used in place of the design basis SSE spectra. For Control Building and Diesel Generator Buildings, the original design basis SSE spectra are used." Since the licensee defined the ESEP review level ground motion (RLGM) as two times the SSE in Section 5.1 of the ESEP report, the ESEP ISRS should be established as two times the SSE-based ISRS.
The staff is seeking an explanation of why the A-46 spectra, instead of the SSE, are used in developing the ESEP ISRS for the Containment. Also, since the A-46 spectrum comparison to the RLGM at the same control point location was not presented, the staff is seeking this information.
The NRC staff reviewed the response prepared by Brunswick and related documents provided on the ePortal system. The document entitled, "Brunswick ESEP Report - RAI Response" provided two important explanations regarding the use of A-46 response spectra for developing the ESEP ISRS. First, the response presented a figure which compared the ground motion response spectrum (GMRS) to the Individual Plant Examination of External Events (IPEEE)
HCLPF spectrum, referred to as the (IHS). The response concluded that this figure shows that the GMRS is bounded by the IHS. The response also indicated, that in accordance with Section 3.3 of the Screening, Prioritization and Implementation Details (SPID), EPRI Report 1025287, dated November 2012, the Brunswick IHS may be used for screening purposes. This suggests to the staff that the Brunswick could be screened out on the basis that the Brunswick IHS bounds the GMRS, provided they meet the other related criteria in the SPID for using the IPEEE results for screening purposes.
The second explanation in the response indicated that the spectra developed for resolution of USI A-46 for the containment is used as the design-basis earthquake anchored to the SSE peak ground acceleration level of 0.16g and multiplied by a factor of two to obtain the RLGM. The response also indicated that the A-46 spectra are adopted in the Brunswick Updated Final Safety Analysis Report (UFSAR), Section 3.10.1.6, which allows USI A-46 methodology for seismic design. No specific information could be identified in this response regarding how the ISRS were developed. Therefore, the staff reviewed the referenced calculation BNP-13-05-600-001, which was identified in the Brunswick response. This calculation contains the RLGM and the ISRS to satisfy the guidance of EPRI Report 3002000704, Seismic Evaluation Guidance, Augmented Approach for the Resolution of Fukushima Near-Term-Task Force Recommendation 2.1 - Seismic, May 2013.
A review of calculation BNP-13-05-600-001 confirms that the Brunswick RLGM for the containment building was developed using two times the A-46 spectrum anchored to 0.16g.
Furthermore, the calculation also demonstrates that for the containment building, the ISRS were developed using two times the A-46 ISRS.
- 2. The results of the screened-out Expedited Seismic Equipment List (ESEL) items for Units 1 and 2 are presented in Attachment B of the ESEP report. However, for two of the items that were screened out (ESEL items 130 and 133 corresponding to direct current power supply for electronic governor-magnetic pickup control for Units 1 and 2, respectively) no entry was identified in the "HCLPF Capacity" column of the table. Therefore, the staff is seeking the HCLPF capacity for these components.
The file "Brunswick ESEP Clarification Questions Responses" on the ePortal system provided a response to this question. The response indicates that Seismic Evaluation Worksheets (SEWS) forms and photos for the two components are provided, and these SEWS forms screened these components out from further review based on their seismic ruggedness. Therefore, the response concluded that it would be appropriate to assign a "greater than RLGM" in the HCLPF capacity column of the HCLPF table for these components.
The specific documentation for the two components were located on the ePortal system as follows:
Item 130: 1-E51-C0002-ES-K604 was located in the file "Z03RO SEWS and Photos_Part 7" on page 701 of 951.
Item 130: 2-E51-C0002-ES-K604 was located in the file "Z03RO SEWS and Photos_Part 9" on page 821 of 951.
For both components, the SEWS forms conclude that the distribution panels are rugged based on the cabinet evaluation, anchorage evaluation, review of systems interaction effects, and the statement that no relays are contained within the panels. Several photos showing the interior of the panels were also provided. Therefore, the licensee concluded that the HCLPF capacity is "greater than RLGM," and thus, these two components can be screened out.
Question Related to Section VI of the Checklist Prepared by NRC Staff
- 1. Section 7 of the ESEP report identifies ESEL items inaccessible for walkdowns. The licensee provided various ways of dispositioning these items and referred to maintenance and testing schedules, installation drawings, photographic evidence and other ways to account for these items. In order to assess the current condition or state of the inaccessible items, the staff asked the licensee to provide more information to support their conclusions, specifically dates of photographs and inspections and other documentation used as part of the Seismic Review Team review.
The staff reviewed the information submitted, which included: SEWS forms and their respective pictures; the A46, A46 outliers and IPEEE submittals. The staff reviewed the SEWS for pictures of inaccessible items and their respective dates.
W. Gideon The audit supported the NRC staff review of the Brunswick ESEP report and related NRC staff requests for additional information. The NRC staff has completed its review based in part on information documented in this audit report. The NRC staff anticipates no further requests for additional information related to the Brunswick ESEP report. Additional information related to the audit is provided below.
If you have any questions, please contact me at (301) 415-1115 or by e-mail at Nicholas.Difrancesco@nrc.gov.
Sincerely,
/RAJ Nicholas J. DiFrancesco, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation
Enclosure:
Audit Report cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrPMBrunswick Resource JLD R/F RidsNrrDorlLPL2-2 Resource RidsNRRJLD Resource SWyman, NRR MShams, NRR NDiFrancesco, NRR DJackson, NRR ADAMS Accession No ..* ML15279A450 *via e-mail OFFICE NRR/JLD/JHMB/PM NRR/JLD/JHMB/LA NRO/DSENRGS/BC NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME NDiFrancesco Slent DJackson MShams NDiFrancesco DATE 12/1/2015 12/9/2015 12/9/2015 12/8/2015 12/9/2015 OFFICAL RECORD COPY