ML042960054
| ML042960054 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 11/02/2004 |
| From: | Colburn T NRC/NRR/DLPM/LPD1 |
| To: | Pearce L FirstEnergy Nuclear Operating Co |
| Colburn T, NRR/DLPM, 415-1402 | |
| References | |
| TAC MC2875, TAC MC2876 | |
| Download: ML042960054 (7) | |
Text
November 2, 2004 Mr. L. William Pearce Vice President FirstEnergy Nuclear Operating Company Beaver Valley Power Station Post Office Box 4 Shippingport, PA 15077
SUBJECT:
BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2 (BVPS-1 AND 2) -
EVALUATION OF 2003 REFUELING OUTAGE STEAM GENERATOR INSPECTION REPORTS (TAC NOS. MC2875 AND MC2876)
Dear Mr. Pearce:
By letters dated April 4, 2003, Agencywide Documents Access and Management System (ADAMS) accession no. ML030980009, April 15, 2003 (ADAMS accession no. ML031080137),
July 24, 2003 (ADAMS accession no. ML032100660), February 12, 2004 (ADAMS accession no. ML040490547), March 4, 2004 (ADAMS accession no. ML040700173), and September 1, 2004 (ADAMS accession no. ML042520356), FirstEnergy Nuclear Operating Company, the licensee for BVPS-1 and 2, submitted reports summarizing the steam generator (SG) tube inspections performed at BVPS-1 during its March 2003 refueling outage. By letters dated October 9, 2003 (ADAMS accession no. ML032880405), March 4, 2004 (ADAMS accession no.
ML040700173), and September 1, 2004 (ADAMS accession no. ML042520356), the licensee submitted reports summarizing the SG tube inspections performed at BVPS-2 during its September 2003 refueling outage. (Note: Public access to ADAMS has been temporarily suspended so that security reviews of publicly available documents may be performed and potentially sensitive information removed. Please check the NRC Web site for updates on the resumption of ADAMS access.)
As discussed in the enclosed evaluation, the staff concludes that the licensee provided the information required by the BVPS-1 and 2 Technical Specifications. In addition, the staff did not identify any technical issues that warrant follow-up action at this time.
Sincerely,
/RA/
Timothy G. Colburn, Senior Project Manager, Section 1 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-334 and 50-412
Enclosure:
Evaluation cc w/encl: See next page
November 2, 2004 Mr. L. William Pearce Vice President FirstEnergy Nuclear Operating Company Beaver Valley Power Station Post Office Box 4 Shippingport, PA 15077
SUBJECT:
BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2 (BVPS-1 AND 2) -
EVALUATION OF 2003 REFUELING OUTAGE STEAM GENERATOR INSPECTION REPORTS (TAC NOS. MC2875 AND MC2876)
Dear Mr. Pearce:
By letters dated April 4, 2003, Agencywide Documents Access and Management System (ADAMS) accession no. ML030980009, April 15, 2003 (ADAMS accession no. ML031080137),
July 24, 2003 (ADAMS accession no. ML032100660), February 12, 2004 (ADAMS accession no. ML040490547), March 4, 2004 (ADAMS accession no. ML040700173), and September 1, 2004 (ADAMS accession no. ML042520356), FirstEnergy Nuclear Operating Company, the licensee for BVPS-1 and 2, submitted reports summarizing the steam generator (SG) tube inspections performed at BVPS-1 during its March 2003 refueling outage. By letters dated October 9, 2003 (ADAMS accession no. ML032880405), March 4, 2004 (ADAMS accession no.
ML040700173), and September 1, 2004 (ADAMS accession no. ML042520356), the licensee submitted reports summarizing the SG tube inspections performed at BVPS-2 during its September 2003 refueling outage. (Note: Public access to ADAMS has been temporarily suspended so that security reviews of publicly available documents may be performed and potentially sensitive information removed. Please check the NRC Web site for updates on the resumption of ADAMS access.)
As discussed in the enclosed evaluation, the staff concludes that the licensee provided the information required by the BVPS-1 and 2 Technical Specifications. In addition, the staff did not identify any technical issues that warrant follow-up action at this time.
Sincerely,
/RA/
Timothy G. Colburn, Senior Project Manager, Section 1 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-334 and 50-412
Enclosure:
Evaluation cc w/encl: See next page DISTRIBUTION:
PUBLIC MO'Brien ACRS PDI-1 R/F TColburn OGC RLaufer GMatakas, RGN-I KKarwarski ALund DLPM/DPR MMurphy ACCESSION NO. ML042960054
- Evaluation input received. No substantive changes made.
OFFICE PDI-1/PM PDI-2/LA EMCB/SC PDI-1/SC NAME TColburn MOBrien ALund*
RLaufer DATE 10/28/04 10/29/04 09/27/04 11/01/04 OFFICIAL RECORD COPY
Beaver Valley Power Station, Unit Nos. 1 and 2 cc:
Mary OReilly, Attorney FirstEnergy Nuclear Operating Company FirstEnergy Corporation 76 South Main Street Akron, OH 44308 FirstEnergy Nuclear Operating Company Regulatory Affairs/Performance Improvement Larry R. Freeland, Manager Beaver Valley Power Station Post Office Box 4, BV-A Shippingport, PA 15077 Commissioner James R. Lewis West Virginia Division of Labor 749-B, Building No. 6 Capitol Complex Charleston, WV 25305 Director, Utilities Department Public Utilities Commission 180 East Broad Street Columbus, OH 43266-0573 Director, Pennsylvania Emergency Management Agency 2605 Interstate Dr.
Harrisburg, PA 17110-9364 Ohio EPA-DERR ATTN: Zack A. Clayton Post Office Box 1049 Columbus, OH 43266-0149 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803 J. H. Lash, Plant Manager (BV-IPAB)
FirstEnergy Nuclear Operating Company Beaver Valley Power Station Post Office Box 4 Shippingport, PA 15077 Rich Janati, Chief Division of Nuclear Safety Bureau of Radiation Protection Department of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 Mayor of the Borough of Shippingport P O Box 3 Shippingport, PA 15077 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Resident Inspector U.S. Nuclear Regulatory Commission Post Office Box 298 Shippingport, PA 15077 FirstEnergy Nuclear Operating Company Beaver Valley Power Station ATTN: R. G. Mende, Director Work Management (BV-IPAB)
Post Office Box 4 Shippingport, PA 15077 FirstEnergy Nuclear Operating Company Beaver Valley Power Station Mr. B. F. Sepelak Post Office Box 4, BV-A Shippingport, PA 15077
ENCLOSURE EVALUATION OF 2003 REFUELING OUTAGE STEAM GENERATOR (SG) TUBE INSPECTION REPORTS FOR BEAVER VALLEY POWER STATION, UNIT NOS. 1 AND 2 (BVPS-1 AND 2)
DOCKET NOS. 50-334 AND 50-412 By letters dated April 4, 2003 (Agencywide Documents Access and Management System (ADAMS) accession no. ML030980009), April 15, 2003 (ADAMS accession no. ML031080137),
July 24, 2003 (ADAMS accession no. ML032100660), February 12, 2004 (ADAMS accession no. ML040490547), March 4, 2004 (ADAMS accession no. ML040700173), and September 1, 2004 (ADAMS accession no. ML042520356), FirstEnergy Nuclear Operating Company, the licensee for BVPS-1 and 2, submitted reports summarizing the SG tube inspections performed at BVPS-1 during its March 2003 refueling outage (1R15). Additional information concerning these inspections was summarized by the Nuclear Regulatory Commission (NRC) staff in a letter dated June 20, 2003 (ADAMS accession no. ML031710065). Information provided in the July 24, 2003, and February 12, 2004, letters pertaining to implementation of the voltage-based tube repair criteria for degradation at the tube support plate elevations was reviewed separately, as documented in NRC letter dated July 14, 2004 (ADAMS accession no.
ML041830118). By letters dated October 9, 2003 (ADAMS accession no. ML032880405),
March 4, 2004 (ADAMS accession no. ML040700173), and September 1, 2004 (ADAMS accession no. ML042520356), the licensee submitted reports summarizing the SG tube inspections performed at BVPS-2 during its September 2003 refueling outage (2R10).
The SGs at BVPS-1 and 2 are Westinghouse model 51 SGs. Each SG contains 3,388 mill annealed Alloy 600 tubes. Each tube has a nominal outside diameter (OD) of 0.875 of an inch and a nominal wall thickness of 0.050 of an inch. The tubes are supported by a number of carbon steel tube support plates and Alloy 600 anti-vibration bars. The tubes in the BVPS-1 SGs were explosively expanded into the tubesheet at both ends for the full length of the tubesheet. The tubes in the BVPS-2 SGs were roll expanded into the tubesheet at both ends for the full length of the tubesheet.
The only sleeves installed through 1R15 in the BVPS-1 SGs are Westinghouse laser-welded sleeves. These sleeves were installed during 1R13 (February 2000). Both tubesheet and tube support plate sleeves were installed during 1R13. There are no sleeves installed through 2R10 in the BVPS-2 SGs.
In addition to the depth-based tube repair criteria, the licensee is also authorized to apply the voltage-based tube repair criteria for predominantly axially oriented OD stress corrosion cracking (SCC) at the tube support plate elevations in both BVPS-1 and 2 SGs. Although authorized to implement the voltage-based repair criteria, the licensee has not found it necessary to implement these criteria at BVPS-2 since few indications subject to this repair criteria have been identified.
The licensee provided the scope, extent, methods, and results of their SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e.,
tube plugging or repair) taken in response to the inspection findings. There were several findings to note as a result of the review of the 2003 inspection reports:
1.
Two tubes in BVPS-1 were plugged because the tubes were in close proximity. These tubes were in row 38 column 62 and in row 39 column 62. The tube in row 38 had a volumetric indication in the freespan area in the U-bend region while the tube in row 39 had no detectable degradation.
2.
During 1R14 and 1R15 several sleeves were found that had collapsed (i.e., experienced a localized region of inward plastic deformation). During 1R14, four sleeved tubes were found to be collapsed. During 1R15, one sleeved tube was found to be collapsed. A visual inspection of the collapsed sleeves during 1R14 indicated that the maximum reduction of the tube inner diameter was approximately 33% (0.22-inch). A rotating probe examination of the hard-roll joint of the collapsed sleeve in 1R15 did not identify any degradation. Each of the tubes was cleaned prior to installation of the sleeves; however, the location of the hard-roll joint was not inspected with a rotating probe prior to sleeve installation. The licensee plans to perform a rotating-probe inspection of the location in the parent tube where the hard-roll sleeve joint will be established prior to installation of any sleeves during future outages. The collapse of these sleeves was attributed to the flow diode effect as discussed in an NRC letter dated December 2, 2003 (ADAMS accession no. ML033290138) and in the submittals referenced above, e.g., the licensees April 15, 2003, letter. An evaluation performed by the licensee has concluded that the structural integrity of the sleeve weld and mechanical roll will not be jeopardized as a result of sleeve collapse from the flow diode effect.
3.
During 1R15, 28 tubes were plugged because of axial indications in the parent tube located behind the lower hard-roll region of the sleeve. All of these axial indications were in the tubesheet region near the tube end, i.e., approximately 1.0 inches up from the tube end and are coincident with the area where a tube plug was previously removed by the Tungsten Inert Gas (TIG) relaxation process. All of the locations with these indications were previously plugged with Framatome roll plugs. Some of the affected tubes had been plugged and deplugged twice, once to replace an Alloy 600 plug, and a second time to return the tube to service. The location where the sleeve joint was established was not examined with a rotating probe prior to sleeve installation.
From the eddy-current method, it could not be determined if the axial indications were related to degradation or a permeability effect related to multiple TIG relaxations.
Indications near the tube end in tubes that had previously been deplugged were also detected at Diablo Canyon Power Plant, Unit 1. These tubes were not sleeved, and the indications were attributed to primary-water(PW) SCC (refer to NRC meeting summary dated July 26, 2004 (ADAMS accession no. ML042010038) and pages 1-2 and 1-3 of of Pacific Gas and Electric Companys letter dated September 7, 2004 (ADAMS accession no. ML042580372)).
4.
In BVPS-1, an axial indication attributed to ODSCC was identified with a rotating probe at a 4.06 volt dent associated with an anti-vibration bar. Since the anti-vibration bars are constructed of Alloy 600 material, this is not considered a classical dent that would be observed at a carbon steel tube support plate. The indication was detected as a result of performing rotating-probe examinations in the U-bend region of 100% of the tubes (the indication was not detected with a bobbin probe). The voltage of the dent was less than the 5-volt threshold at which all dents were examined with the rotating probe.
5.
In 2002 at BVPS-2 (2R9), axially oriented PWSCC was detected in 2 tubes at hot-leg tube support plate dents and ODSCC was detected in one tube at a free span ding. In 2003 (2R10), neither PWSCC at tube support plates nor ODSCC at dings were reported.
6.
Since 2000, crack-like indications have been reported at dent and ding locations in the BVPS-1 and 2 SGs and some, if not all, of these indications were only detected with a rotating probe. In several instances, indications were reported at dents at tube supports and at anti-vibration bars which measured less than 5 volts. In addition, crack-like indications have been reported at dings. Some of these dings had voltages near 5 volts.
7.
At BVPS-2 in 2003, only circumferential ODSCC was reported at the tube-to-tubesheet expansion transition. All indications are associated with the expansion transition. Axial and circumferential ODSCC and PWSCC have not been observed below the expansion transition. The scope of examination of the hardroll expansion transition area was from 6 inches above the top-of-the-tubesheet (TTS) to 3 inches below the TTS.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the BVPS-1 and 2 Technical Specifications. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up action at this time since: (1) the inspections appear to be consistent with the objective of detecting potential tube degradation and (2) the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
Principal Contributors: M. Murphy K. Karwoski Date: November 2, 2004