ML100140543
| ML100140543 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  (DPR-051) |
| Issue date: | 01/20/2010 |
| From: | Kalyanam N Plant Licensing Branch IV |
| To: | Entergy Operations |
| Kalyanam N, NRR/DORL/LPL4, 415-1480 | |
| References | |
| TAC ME1009 | |
| Download: ML100140543 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 20, 2010 Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT NO.1 - EVALUATION OF FALL 2008 REFUELING OUTAGE (1R21) STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME1009)
Dear Sir or Madam:
By letter dated March 30, 2009, Entergy Operations Inc. (Entergy, the licensee), submitted information pertaining to its 2008 steam generator (SG) tube inspections at the Arkansas Nuclear One, Unit 1 (ANO-1) during the fall 2008 refueling outage ('I R21).
In addition, the licensee and the U.S. Nuclear Regulatory Commission (NRC) staff held a conference call on November 8, 2008, and a Category 1 public meeting on December 15, 2009, to discuss the SG inspection results during past outages and to address issues related to bowed tie rods and tube support plate wear. Summaries of the conference call on November 8, 2008, and the public meeting on December 15, 2009, are available in the Agencywide Documents Access and Management System in ADAMS Accession Nos. ML083380334 and ML093520058, respectively.
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 staff's review of the reports is enclosed.
If you have any questions, please contact me at (301) 415-1480 or bye-mail at kaly.kalyanam@nrc.gov.
Sincerely, N. Kaly 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 ARKANSAS NUCLEAR ONE, UNIT 1 EVALUATION OF THE STEAM GENERATOR INSPECTIONS PERFORMED DURING THE FALL 2008 REFUELING OUTAGE (1R21)
DOCKET NO. 50-313 By letter dated March 30, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090920254), Entergy Operations, Inc., the licensee, submitted information summarizing the results of its fall 2008 refueling outage (1 R21) steam generator (SG) tube inspections at Arkansas Nuclear One, Unit 1 (ANO 1). In addition, the licensee and the U.S. Nuclear Regulatory Commission (NRC) staff held a conference call on November 8, 2008, and a Category 1 public meeting on December 15, 2009, to discuss the SG inspection results during past outages and to address issues related to bowed tie rods and tube support plate wear. Summaries of the November 8, 2008, conference call and the December 15, 2009, public meeting are available in ADAMS Accession Nos. ML083380334 and ML093520058, respectively.
The SGs at ANO-1 were replaced in 2005 with enhanced once-through steam generators manufactured by AREVA. The vertical SGs are straight shell-and-tube heat exchangers, each containing 15,597 thermally treated Alloy 690 tubes. Each tube has a nominal outside diameter of 0.625 inches and a nominal wall thickness of 0.037 inches. The tubes were hydraulically expanded for the full depth of the tubesheet and are supported by 15 tube support plates (TSPs). The TSPs are constructed of SA 240 Type 410 stainless steel and contain broached trefoil shaped holes.
The licensee provided the scope, extent, methods, and results of its SG tube inspections in its March 30, 2009, letter. In addition, the licensee described corrective actions (Le., tube plugging) taken in response to the inspection findings. The 2008 inspections were performed during refueling outage 21 (1 R21) and marked the second inservice inspection of the SGs since replacement.
As a result of its review of the reports, the NRC staff has the following comments and observations:
Tie rod bowing, due to one or more locked TSPs, was detected in SG A. The amount of bowing increased slightly from 1R20 to 1R21. The possible causes, consequences, and corrective actions were discussed in detail in the public meeting on December 15, 2009 (see ADAMS Accession No. ML093500503 for the proprietary version and ADAMS Accession No. ML093500565 for the non-proprietary version of the meeting handouts).
Enclosure
- 2 During 1R21, 990 indications of wear were detected in SG A at the TSPs and 1,029 indications of wear were detected in SG B at the TSPs. The average depth of these indications is less than 10 percent through wall.
Eight tubes in SG A were plugged, which included four tubes due to TSP wear and four tubes (preventively plugged) due to tube bowing. Five tubes in SG B were plugged due to TSP wear.
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. The staff will continue to monitor the licensee's assessment of the tie rod bowing issue.
January 20, 2010 Vice President, Operations Arkansas Nuclear One Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 SUB,JECT:
ARKANSAS NUCLEAR ONE, UNIT NO.1 - EVALUATION OF FALL 2008 REFUELING OUTAGE ('IR21) STEAM GENERATOR TUBE INSPECTIONS (TAC NO. ME1009)
Dear Sir or Madam:
By letter dated March 30, 2009, Entergy Operations Inc. (Entergy, the licensee), submitted information pertaining to its 2008 steam generator (SG) tube inspections at the Arkansas Nuclear One, Unit 1 (ANO-1) during the fall 2008 refueling outage (1 R21).
In addition, the licensee and the U.S. Nuclear Regulatory Commission (NRC) staff held a conference call on November 8, 2008, and a Category 1 public meeting on December 15, 2009, to discuss the SG inspection results during past outages and to address issues related to bowed tie rods and tube support plate wear. Summaries of the conference call on November 8, 2008, and the public meeting on December 15, 2009, are available in the Agencywide Documents Access and Management System in ADAMS Accession Nos. ML083380334 and ML093520058, respectively.
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 staff's review of the reports is enclosed.
If you have any questions, please contact me at (301) 415-1480 or bye-mail at kaly.kalyanam@nrc.gov.
Sincerely, IRA!
N. Kaly 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:
PUBLIC RidsNrrPMANO Resource LPLIV Reading RidsOgcRp Resource RidsAcrsAcnw_MailCTR Resource RidsRgn4MailCenter Resource RidsNrrDciCsgb Resource KKarwoski, DCI/CSGB RidsNrrDorlLpl4 Resource AJohnson, DCI/CSGB RidsNrrLAJBurkhardt Resource ADAMS Accession No ML100140543
- memo dated OFFICE NRRlLPL4/PM NRRlLPL4/LA DC/CSGB/BC NRRlLPL4/BC NRRlLPL4/PM NAME NKalyanam JBurkhardt RTaylor*
MMarkley NKalyanam DATE 1/15/10 1/15/10 1/14/10 1/20/10 1/20/10 OFFICIAL RECORD COpy