L-88-009, Status Update for NRC Bulletin 88-09, Thimble Tube Thinning in Westinghouse Reactors
| ML091100397 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 04/13/2009 |
| From: | Castell C Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BL-88-009, NRCB 88-09, RNP-RA/09-0025 | |
| Download: ML091100397 (2) | |
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Progress Energy NRCB 88-09 Serial: RNP-RA/09-0025 APR 113 2009 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261/LICENSE NO. DPR-23 STATUS UPDATE FOR NRC BULLETIN 88-09, "THIMBLE TUBE THINNING IN WESTINGHOUSE REACTORS" Ladies and Gentlemen:
By letter dated July 26, 1988, the NRC issued Bulletin (NRCB) No. 88-09, "Thimble Tube Thinning in Westinghouse Reactors," which required establishment and implementation of a thimble tube inspection program. The response for H. B. Robinson Steam Electric Plant (HBRSEP), Unit No. 2, was provided to the NRC by letter dated February 8, 1991, which confirmed that an inspection program had been established.
The nominal inspection frequency for eddy current inspection of the thimble tubes at HBRSEP, Unit No. 2, had been every other refueling outage, which is approximately every 3 years. By letter dated January 20, 1999, the NRC was informed that as a result of inspections performed during the preceding six (6) operating cycles, the planned inspections for Refueling Outage (RO) 19 would be deferred to RO-20. By letter dated May 27, 2003, the NRC was informed that HBRSEP, Unit No. 2, would extend the frequency for eddy current inspection of the thimble tubes to every third refueling outage. That letter also stated that future inspection intervals would be adjusted (shortened or lengthened) based on the results of the inspection program.
The following status update is hereby provided:
There are a total of 50 thimble tubes, three of which were intentionally plugged or capped, but not because of tube leaks. The remaining 47 tubes have been inspected from the seal table to the fuel assemblies. Eddy current inspection of the thimble tubes has been performed during RO-13 (January 1991), RO-15 (October 1993), RO-17 (September 1996), RO-20 (April 2001), and RO-23 (September 2005).
Progress Energy Carolinas, Inc.
Robinson Nuclear Plant 3581 West Entrance Road Hartsville, SC 29550
United States Nuclear Regulatory Commission Serial: RNP-RA/09-0025 Page 2 of 2 During RO-23, no wall loss or damage was detected in any of the 47 tubes. Therefore, based on the existing condition of the thimble tubes and the previous inspection results, the frequency of eddy current inspection of the thimble tubes is being changed from every third refueling outage to every sixth refueling outage.
This information is being provided in response to the NRC request to provide the results of the thimble tube inspection program and the results for RO-23. There is no response or review requested for this submittal. The results of thimble tube eddy current inspections will continue to be reviewed after each inspection and the inspection frequency will be further adjusted as deemed appropriate based on the results of these inspections.
No new commitments are included in this letter.
If you have any questions concerning this matter, please contact me at (843) 857-1626.
Sincerely, C. A. Castell Supervisor - Licensing/Regulatory Programs CAC/ahv c:
L. A. Reyes, NRC, Region II NRC Resident Inspector M. G. Vaaler, NRC, NRR