ML14273A259
| ML14273A259 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 10/28/2014 |
| From: | Bill Dean Office of Nuclear Reactor Regulation |
| To: | Limpias O Nebraska Public Power District (NPPD) |
| Balazik M, NRR/JLD, 415-2856 | |
| References | |
| TAC MF3734 | |
| Download: ML14273A259 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 28, 2014 Mr. Oscar A Limpias Vice President-Nuclear and CNO Nebraska Public Power District Cooper Nuclear Station 72676 648A Avenue P.O. Box 98 Brownville, NE 68321
SUBJECT:
COOPER NUCLEAR STATION- SCREENING AND PRIORITIZATION RESULTS OF INFORMATION PROVIDED PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULA T/ONS PART 50, SECTION 50.54(f),
SEISMIC HAZARD REEVALUATIONS FOR RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA DAI-ICHI ACCIDENT (TAC NO. MF3734)
Dear Mr. Limpias:
The purpose of this letter is to transmit to Nebraska Public Power District (NPPD) the results for Cooper Nuclear Station (CNS) regarding the U.S. Nuclear Regulatory Commission's (NRC) screening and prioritization review. The NRC staff reviewed the CNS Seismic Hazard Evaluation and Screening Report (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14094A048) and evaluated the information using industry guidance.
By memorandum dated May, 21, 2014 (ADAMS Accession No. ML14136A126) the NRC enclosed preliminary ground motion response spectra (GMRS) plots used to inform the NRC's decision on identifying and prioritizing the plants that would perform a risk evaluation. In several discussions with your staff, the NRC staff could not resolve differences between NPPD's submitted GMRS and the NRC's preliminary GMRS. Because the staff's preliminary GMRS exceeds the Safe Shutdown Earthquake (SSE) for CNS in both the 1-10 Hertz (Hz) range and greater than 10 Hz range, the NRC staff concludes that CNS screens in to perform a seismic risk evaluation (Prioritization Group 3), expedited approach, high frequency evaluation, and spent fuel pool evaluation. This result is consistent with the information contained in a letter to NPPD from the NRC dated May 9, 2014 (ADAMS Accession No. ML14111A147). Furthermore, NPPD should finalize and submit CNS's expedited approach to the NRC no later than May 1, 2015. As communicated with your staff previously, the NRC staff would consider a public meeting with NPPD to align on the appropriate GMRS to use in completing the seismic risk evaluation.
This letter transm1ts the NRC staffs result of the screening and prioritization of the seismic hazard submittal for CNS. It does not convey the staffs final determination regarding the adequacy of any plant's calculated hazard. As such, the NRC staff will continue its review of the seismic hazard reevaluation submittal, and the NRC staff may request additional plant-specific information to support this review. The NRC staff plans to issue an assessment for CNS on the reevaluated seismic hazard no later than the third quarter 2015.
- 0. Limpias BACKGROUND On March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations (1 0 CFR), Part 50, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) (ADAMS Accession No. ML12053A340). The purpose of that request was to gather information concerning, in part, seismic hazards at each operating reactor site and to enable the NRC staff to determine whether licenses should be modified, suspended, or revoked. Further, the 50.54(f) letter stated that the NRC would provide screening and prioritization results to indicate deadlines, if necessary, for individual plants to complete seismic risk evaluations that assess the total plant response to the reevaluated seismic hazard. In response to the 50.54(f) letter, all addressees committed to follow the Electric Power Research Institute Report (EPRI),
"Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," 1 as supplemented by the EPRI Report, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic"2 (referred to as the expedited approach).
In response to the 50.54(f) letter, NPPD submitted its reevaluated seismic hazard for CNS in March 2014. The CNS Seismic Hazard Evaluation and Screening Report specified that based on the results, CNS screens out for performing any further evaluations. Subsequently, by letter dated May 9, 2014 (ADAMS Accession No. ML14111A147), the NRC staff informed all licensees of operating reactors in the central and eastern United States of the screening and prioritization results to support completing seismic risk and limited-scope evaluations, as described in Enclosure 1 of the 50.54(f) letter. Accordingly, during the NRC's screening and prioritization 30-day review, the staff identified several plants where a determination could not be made and interactions with the licensee were needed to reach resolution. The staff designated these plants as conditionally screened-in because additional information was needed to support a screening and prioritization decision. In the May 9, 2014 letter, the NRC staff identified that CNS conditionally screens in to perform a seismic risk (Prioritization Group 3), high frequency, and spent fuel pool evaluation for the purposes of screening and prioritization.
SCREENING PROCESS As discussed in the May 9, 20141etter and as previously stated above, the NRC staff's screening review was performed using the EPRI Report, "Seismic Evaluation Guidance:
Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic", as supplemented by the EPRI Report, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic." For the purpose of the licensees' analyses and the NRC staff's review, the SPID identified three frequency ranges of particular interest: 1-10 Hz, a low frequency range of less than 2.5 Hz, and a high frequency range of greater than 10 Hz. The frequency range of 1-1 0 Hz was the focus of the screening review for performing a risk evaluation, as this range has the greatest potential effect on the performance of equipment and 1
The SPID guidance document can be found in ADAMS under Accession No. ML12333A170. The staff endorsement letter for the SPID guidance can be found in ADAMS under Accession No. ML12319A074.
2 The Expedited Approach guidance document can be found in ADAMS under Accession No. ML13102A142.
- 0. Limpias structures important to safety. Additional information, including specific details related to the NRC staff's focus and scope of review, are contained in the May 9, 2014, letter.
FINAL SCREENING AND PRIORITIZATION Seismic Risk Limited-scope Evaluations Expedited Screening Evaluation High Low Spent Approach Result (Prioritization Frequency Frequency Fuel Pool Evaluation Group) Evaluation Evaluation Evaluation Copper Nuclear Station In X 3 X X If you have any questions on this matter, please contact Michael F. Balazik, Project Manager for the Japan Lessons-Learned Division at 301-415-2856 or at Michaei.Balazik@nrc.gov.
Sincerely,
~tt.JU. 6 w ~*
William M. Dean, Director Office of Nuclear Reactor Regulation Docket No. 50-298 cc: Listserv
..* ML14273A259 *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRR/JLD/JHMB/BC NRO/DSEA/RGS2/BC NAME MBalazik SLent SWhaley DJackson DATE 10/03/14 10/03/14 10/06/14 10/06/14 OFFICE NRR/DORLILPL4-1 /PM* NRR/JLD/D OGC NRR/D NAME EOesterle JDavis(MFranovich for} CEngland WDean (JUhle for)
DATE 10/08/14 10/17/14 10/09/14 10/28/14