ML110490401
| ML110490401 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/25/2011 |
| From: | Kalyanam N Plant Licensing Branch IV |
| To: | Entergy Operations |
| Kalyanam N, NRR/DORL/LPL4, 415-1480 | |
| References | |
| TAC ME4503 | |
| Download: ML110490401 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 25, 2011 Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 1 - EVALUATION OF 2010 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (TAC NO. ME4503)
Dear Sir or Madam:
By letters dated July 29 and November 18, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML102250418 and ML103220311, respectively),
Entergy Operations, Inc. (the licensee), submitted information summarizing the results of the steam generator tube inspections performed at Arkansas Nuclear One, Unit 1 during the spring 2010 refueling outage 1R22. Additionally, the licensee and the Nuclear Regulatory Commission (NRC) staff held a telephone conference call on March 29,2010, which is summarized in a letter dated April 12, 2010 (ADAMS Accession No. ML100960402).
The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by its technical specifications and that no additional follow-up is required at this time. The NRC staff review of the reports is enclosed.
Sincerely, N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-313
Enclosure:
As stated cc w/encl: Distribution via Listserv
SUMMARY
OF REVIEW BY THE OFFICE OF NUCLEAR REACTOR REGULATION ENTERGY OPERATIONS, INC.
ARKANSAS NUCLEAR ONE, UNIT 1 2010 STEAM GENERATOR TUBE INSPECTIONS DOCKET NO. 50-313 By letters dated July 29 and November 18, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML102250418 and ML103220311, respectively),
Entergy Operations, Inc. (the licensee), submitted information summarizing the results of the steam generator (SG) tube inspections performed at Arkansas Nuclear One, Unit 1 (ANO-1) during the spring 2010 refueling outage 1R22. Additionally, the licensee and the Nuclear Regulatory Commission (NRC) staff held a telephone conference call on March 29,2010, which is summarized in a letter dated April 12, 2010 (ADAMS Accession No. ML100960402).
The two SGs at ANO-1 are AREVA once through steam generators (OTSG). Each OTSG contains approximately 15,597 thermally treated Alloy 690 tubes. Each tube has a nominal diameter of 0.625-inch and a nominal wall thickness of 0.037-inch. Each tube is hydraulically expanded for the full length of both tubesheets in a sequence designed to produce a tensile pre load on the tubes. The SG tube support plates are 1.18-inch thick heat-treated 410 stainless steel with broached trefoil-holes. The tube support plates are held in place with stay rods. For additional information concerning the design of the replacement OTSGs, see the NRC staffs summary of a conference call with the licensee held on August 10, 2005 1, and the licensee's letter enclosing the ANO-1 report with the results of SG tube inspections conducted during December 2005 2 .
In its letters dated July 29 and November 18, 2010, the licensee provided the scope, extent, methods, and results of its SG tube inspections. In addition, the licensee described corrective actions taken in response to the inspection findings.
Holland, D" U.S. Nuclear Regulatory Commission, letter to Jeffrey S. Forbes, Entergy Operations, Inc., "Arkansas Nuclear One, Unit 1 - Summary of Conference Call with Entergy Operations, Inc., to Discuss Replacement Steam Generators (TAC No. MA7389)," dated March 9, 2006 (ADAMS Accession No. ML060590367).
2 James, D. E., Entergy Operations, Inc" letter to U.S, Nuclear Regulatory Commission, "Steam Generator Tubing Inspection Report, Arkansas Nuclear One - Unit 1, Docket No, 50-313, License No.
DPR-51 ," dated June 14, 2006 (ADAMS Accession No, ML061730358),
Enclosure
-2 Based on its review of the reports submitted, the NRC staff has the following observations and comments:
- During the spring 2007 refueling outage, ANO-1 detected tie rod bowing in SG A.
due to one or more locked tube support plates. The amount of bowing slightly increased from 1R21 to 1R22. The possible causes, consequences, and corrective actions were discussed in detail in the public meeting held on December 15,2009. 3
- SG A continues to be the only SG affected by bowing. The bowing is on the Z-axis side and is dominant in rows 64 and 68.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by its technical specifications. In addition, the staff concludes that there are no technical issues that warrant follow-up action at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
3 Kalyanam, K., U.S. Nuclear Regulatory Commission, "Summary off December 15, 2009, Meeting With Entergy Operations, Inc., on Arkansas Nuclear One, Unit 1, Steam Generator Issues," dated January 6, 2010 (ADAMS Accession No. ML093520058).
February 25, 2011 Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 1 - EVALUATION OF 2010 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (TAC NO. ME4503)
Dear Sir or Madam:
By letters dated July 29 and November 18, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML102250418 and ML103220311, respectively),
Entergy Operations, Inc. (the licensee), submitted information summarizing the results of the steam generator tube inspections performed at Arkansas Nuclear One, Unit 1 during the spring 2010 refueling outage 1R22. Additionally, the licensee and the Nuclear Regulatory Commission (NRC) staff held a telephone conference call on March 29, 2010, which is summarized in a letter dated April 12, 2010 (ADAMS Accession No. ML100960402).
The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by its technical specifications and that no additional follow-up is required at this time. The NRC staff review of the reports is enclosed.
Sincerely, IRA by Lauren Kate Gibson fori N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-313
Enclosure:
As stated cc w/encl: Distribution via Listserv DISTRIBUTION:
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DATE 2/24/11 2/24/11 2/17/11 2/25/11 2/25/11 OFFICIAL RECORD COpy