ML14111A077
| ML14111A077 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 04/28/2014 |
| From: | Peter Bamford Plant Licensing Branch IV |
| To: | Halpin E Pacific Gas & Electric Co |
| Bamford P | |
| References | |
| TAC MF3891 | |
| Download: ML14111A077 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 28, 2014 Mr. Edward D. Halpin Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 56, Mail Code 104/6 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON POWER PLANT, UNIT NO 2-ACCEPTANCE REVIEW OF RELIEF REQUEST SWOL-REP-1 U2 (TAC NO. MF3891)
Dear Mr. Halpin:
By letter dated April 7, 2014 (Agencywide Documents Access and Management System Accession No. ML14101A246), Pacific Gas and Electric Company (PG&E), submitted Relief Request SWOL-REP-1 U2, for Diablo Canyon Power Plant (DCPP), Unit 2. The request proposes an alternative to certain repair requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components." The requirements for which relief is being requested relate to three existing structural weld overlays (SWOLs), previously applied to welds associated with nozzles on the DCPP, Unit 2 pressurizer. The SWOLs were applied as a preemptive measure against the potential for primary water stress corrosion cracking of dissimilar metal welds.
The purpose of this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staff's acceptance review of this request. The acceptance review was performed to determine if there is sufficient technical information in scope and depth to allow the NRC staff to complete its detailed technical review. The acceptance review is also intended to identify whether the application has any readily apparent information insufficiencies in its characterization of the regulatory requirements or the licensing basis of the plant.
The NRC staff has reviewed PG&E's request and concluded that it does provide technical information in sufficient detail to enable the staff to complete its detailed technical review and make an independent assessment regarding the acceptability of the proposed request in terms of regulatory requirements and the protection of public health and safety and the environment.
However, in the submittal dated April 7, 2014, PG&E indicates that a supplemental analysis, regarding a flaw size evaluation that accounts for sizing variations in future inspections, will be submitted "no later than June 16, 2014." Based on the timing of the submittal dated April 7, 2014, and the proposed schedule for the providing the supplemental analysis, the NRC staff cannot provide PG&E with any assurance that the requested disposition date of July 31, 2014, will be met. The NRC staff will make every effort to evaluate SWOL-REP-1 U2, prior to the completion of the upcoming fall refueling outage at DCPP Unit 2.
Given the lesser scope and depth of the acceptance review as compared to the detailed technical review, there may be instances in which issues that impact the NRC staff's ability to complete the detailed technical review are identified, despite completion of an adequate
acceptance review. You will be advised of any further information needed to support the NRC staff's detailed technical review by separate correspondence.
If you have any questions, please contact me at 301-415-2833 or via e-mail at Peter. Bamford@nrc.gov.
Docket No. 50-323 cc: Distribution via Listserv Sincerely, Peter J. Bamford, Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
ML14111A077 Sincerely, IRA/
Peter J. Bamford, Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation OFFICE NRR/DORLILPL4-1/PM NRR/DORLILPL4-1/LA NRR/DORL/LPL4-1/BC NRR/OORL/LPL4-1/PM NAME PBamford JBurkhardt MMarkley PBamford DATE 4/28/14 4/28/14 4/28/14 4/28/14