ML073510413
| ML073510413 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 11/28/2007 |
| From: | Rencurrel D South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-07002239, TAC MA6850, TAC MA6851 | |
| Download: ML073510413 (3) | |
Text
Nuclear Operating Company South TeWas Project Electric Generating Station PO. Box 289 Wadsworth. Texas 77483 November 28, 2007 NOC-AE-07002239 1 OCFR50 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Correction of Statements made in.ReliefReniuest RR-FNG-2-15~
Correction
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References:
- 1. Letter dated October 7, 1999, from J. J. Sheppard, STPNOC, to NRC Document Control Desk, "Request for Relief from ASME Boiler and Pressure Vessel Code Section XI Requirements (Relief Request RR-ENG-2-15)"
[NOC-AE-000625]
- 2.
Letter dated July 17, 2000, from T. J. Jordan, STPNOC, to NRC Document Control Desk, "Supplement to Request for Relief from ASME Boiler and Pressure Vessel Code Section XI Requirements of IWA-5242(a) (RR-ENG-2-15)"
[NOC-AE-00000884, ML003735206]
- 3.
Letter dated January 31, 2001, from Robert A. Gramm, NRC, to William T. Cottle, STPNOC, "South Texas Project, Units 1 and 2 - Request for Relief (RR-ENG-2-15) from ASME Code,Section XI Requirements (TAC Nos. MA6850 and MA685 1)"
[ST-AE-NOC-00000765, ML010310285]
STP Nuclear Operating Company (STPNOC) is submitting this letter to correct certain statements made in connection with Relief Request RR-ENG-2-15 (Reference 1 and Reference 2). The relief request was approved by Reference 3. STPNOC recently identified that References 1 and 2 contain incorrect statements. The purpose of this letter is to correct this information in the STP docket.
In Reference 1, STPNOC stated that:
Review of the material type and chromium content of bolted connections at the South Texas Project determined that bolting materials used in borated system applications that are insulated have a chromium content of at least 10%.
In Reference 2, STPNOC stated that:
Bolts in applications at the South Texas Project that could come in contact with borated water contain at least 12% chromium, which exceeds the 10% chromium content required under code case N-616.
The statements above indicate that all the bolted connections in these systems are eligible for the requested relief, which is not correct. During a recent station assessment, STPNOC identified that there are bolted connections in various components that have less than 10% chromium content (e.g., residual heat removal heat (RHR) exchanger flanges, pressurizer manway bolting, steam generator primary side manway bolting, reactor pressure vessel studs, letdown heat exchanger flanges). In addition, some bolted STI 32229576
)40Y7
NOC-AE-07002239 Page 2 of 3 connections have SA-194 Gr. 6 nuts, which have an allowable chromium content of 11.5% to 13.5%
(acceptable per Code Case N-616, but possibly less than 12% noted in Reference 2).
Since the NRC's approval of STPNOC's relief request was limited to bolting materials that had greater than 10% chromium content, correction of these statements does not affect the current licensing basis for STP Units 1 & 2.
For the bolted connections where STPNOC incorrectly applied the relief request, STPNOC has taken the action required by the Technical Specifications and the STP corrective action program for a missed surveillance requirement. The missed surveillance has been successfully performed for the RHR and pressurizer manway connections. Evaluations have been performed for the components where inspection is not practical with the plant at power and STPNOC has determined it is acceptable to defer the surveillance until the next refueling outage (spring 2008 for Unit 1 and fall 2008 for Unit 2), in accordance with the provisions of the Technical Specifications. STPNOC has identified no safety significant issues associated with the missed surveillance from the improper application of the relief request.
The incorrect statements were made about eight years ago. STPNOC's review has determined the most likely cause is that the individuals performing the document review for the relief request overlooked the connections to components such as heat exchangers. STPNOC reviewed other relief requests submitted in that time frame and found no others with similar errors.
Please contact Mr. A. W. Harrison at (361) 972-7298, or me at (361) 972-7867 if you have any questions.
There are no commitments in this letter.
David W. Rencurrel Vice President, Engineering & Strategic Projects Awh/
NOC-AE-07002239 Page 3 of 3 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mohan C. Thadani Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 7 D1) 11555 Rockville Pike Rockville, MD 20852 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code: MN 16 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 Richard A. Ratliff Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756-3189 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan C. Thadani U. S. Nuclear Regulatory Commission Thad Hill Eddy Daniels Marty Ryan Harry Holloway Steve Winn NRG South Texas LP Ed Alarcon J. J. Nesrsta R. K. Temple Kevin Pollo City Public Service Jon C. Wood Cox Smith Matthews C. Kirksey City of Austin