ML111650362

EPU - Request for Additional Information (Reactor Vessel and Internals)

ML111650362
Person / Time
Site:	Saint Lucie
Issue date:	06/14/2011
From:	Orf T Plant Licensing Branch II
To:	Wasik C Florida Power & Light Co
Orf, T J, NRR/DORL/301-415-2788
References
Download: ML111650362 (2)

Text

From: Orf, Tracy Sent: Tuesday, June 14, 2011 1:13 PM To: 'Wasik, Chris'

Subject:

St. Lucie Unit 1 EPU - Request for additional information (Reactor Vessel and Internals)

ADAMSAccessionNumber: ML111120260

Dear Mr. Wasik,

By letter dated November 22, 2010 (Agencywide Documents Access and Management System Accession No. ML103560415) Florida Power & Light Company (the licensee) submitted a license amendment request for St. Lucie Unit 1.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and has concluded that additional information is required from the licensee in order for the NRC staff to complete their review. The questions below describe these requests for additional information (RAls).

The NRC requests that the licensee respond to these RAls within 30 days of the date of this e-mail. If the licensee concludes that more than 30 days are required to respond to the RAls, the licensee should request additional time, including a basis for why the extension is needed.

Please contact me at the number below or by e-mail if you have any questions on this issue or if you require additional time to submit your responses.

Sincerely, Tracy J. Orf, Project Manager St. Lucie Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Phone: (301) 415-2788 REQUEST FOR ADDITIONAL INFORMATION (RAI)

REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE ST. LUCIE PLANT, UNIT NO.1 DOCKET NO. 50-335 CVIB-7

RAI CVIB-5 (Ref. 1) part a requested the licensee to describe the method of determining if additional RVI components become susceptible to the aging effects of 1) cracking due to stress corrosion cracking or irradiation assisted stress corrosion cracking (IASCC), 2) reduction of fracture toughness due to irradiation embrittlement; 3) loss of material due to wear; 4) loss of mechanical closure integrity due to IASCC, irradiation embrittlement, irradiation creep, or stress relaxation; 5) loss of preload due to stress relaxation; and 6) dimensional change due to void swelling. RAI CVIB-5 part c requested the licensee clarify whether any additional reactor vessel internals components were determined to be susceptible to the aging effects listed in part a of the question as a result of extended power uprate (EPU), compared to those listed as susceptible to these mechanisms in the license renewal application.

The response to RAI CVIB-5 indicates that it was determined that certain components may be susceptible to additional degradation mechanisms, compared to the degradation mechanisms identified in the St. Lucie, Units 1 and 2 License Renewal Application (LRA) for those components, under EPU conditions. Specifically, the fuel alignment plate, control element assembly shroud assemblies, and the upper guide structure support plate may be susceptible to irradiation embrittlement. Cracking of these components was previously identified in the LRA.

The licensee stated that the license renewal documentation would be updated to reflect this change. However, the response does not indicate specifically which aging management programs AMP(s) will manage the additional aging effects or whether changes to the existing identified AMPs will be necessary. The staff therefore requests the following information:

a) Identify the AMP(s) that will manage aging effects associated with additional aging mechanisms that will affect certain components as a result of EPU.

b) Discuss the adequacy of the existing AMPs to manage the aging effects associated with the additional aging mechanisms, and describe any changes that are necessary to the existing identified AMPs.

CVIB-8 NUREG-1779 (Ref. 2) documents the following commitments related to aging management of the St. Lucie, Units 1 and 2 RVI components:

Commitment UFSAR Supplement Implementation Source Location Schedule (LRA Appendix A1)

Submit a report 18.1.4, Reactor Prior to the end of the LRA Appendix B, summarizing the Vessel initial operating Subsection 3.1.4 aging Internals Inspection license Response to RAI effects applicable to Program term. 3.1-1 (FPL letter reactor vessel L-2002-157) internals including a description of the inspection plan.

Perform a one-time 18.1.4, Reactor During the period of LRA Appendix B, inspection of the Vessel extended operation. Subsection 3.1.4 reactor Internals Inspection vessel internals. Program Although Florida Power & Light Company (FPL) committed to submit an RVI component inspection program for St. Lucie, Units 1 and 2 prior to the period of extended operation, FPL did not specifically commit to submit an RVI component inspection program conforming to the industrys standard program. Therefore, the staff requests the licensee discuss their plans to implement the industrys recommended inspection and evaluation guidelines for RVI components as documented in topical report MRP-227, Rev. 0, as modified by the staffs SE expected to be issued during June 2011, or the approved version of the topical report (MRP-227-A), for Saint Lucie, Unit 1.

References

1. Letter from Tracy J. Orf to Mano Nazar dated April 19, 2011;

Subject:

St. Lucie Plant, Unit 1 - Request For Additional Information Regarding License Amendment Request For Extended Power Uprate (TAC NO. ME5091) (ADAMS Accession No. ML111010098)

2. NUREG-1779, Safety Evaluation Report Related to the License Renewal of St. Lucie Nuclear Plant, Units 1 and 2, Docket Nos. 50-335 and 50-389, Florida Power & Light Company, September, 2003 (ADAMS Accession No. ML032940205)