ML021440045
| ML021440045 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/24/2002 |
| From: | Edison G NRC/NRR/DLPM/LPD2 |
| To: | Christian D Virginia Electric & Power Co (VEPCO) |
| Edison G E, NRR/DLPM, 415--1448 | |
| References | |
| TAC MB4773 | |
| Download: ML021440045 (8) | |
Text
May 24, 2002 Mr. David A. Christian Sr. Vice President - Nuclear Virginia Electric and Power Company Innsbrook Technical Center Glen Allen, Virginia 23060
SUBJECT:
SURRY POWER STATION UNIT 2 -
SUMMARY
OF CONFERENCE CALL REGARDING STEAM GENERATOR INSPECTION (TAC NO. MB4773)
Dear Mr. Christian:
The purpose of this letter is to document our conference call with Virginia Electric and Power Company (VEPCO) on April 17, 2002. The purpose of that call was for VEPCO to inform NRC staff of the results of steam generator tube inspection at Surry Unit 2 during the spring 2002 refueling outage. A summary of the conference call is provided as Enclosure 1. An inspection work scope provided by VEPCO to facilitate the discussion is provided as Enclosure 2. A list of participants in the call is included as Enclosure 3.
This completes our effort under TAC No. MB4773 and the TAC is closed.
If you have any questions, please call me at (301) 415-1448.
Sincerely,
/RA/
Gordon E. Edison, Senior Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation
Enclosures:
As stated Docket No. 50-281 cc w/ encl: See next page
May 24, 2002 Mr. David A. Christian Sr. Vice President - Nuclear Virginia Electric and Power Company Innsbrook Technical Center Glen Allen, Virginia 23060
SUBJECT:
SURRY POWER STATION UNIT 2 -
SUMMARY
OF CONFERENCE CALL REGARDING STEAM GENERATOR INSPECTION (TAC NO. MB4773)
Dear Mr. Christian:
The purpose of this letter is to document our conference call with Virginia Electric and Power Company (VEPCO) on April 17, 2002. The purpose of that call was for VEPCO to inform NRC staff of the results of steam generator tube inspection at Surry Unit 2 during the spring 2002 refueling outage. A summary of the conference call is provided as Enclosure 1. An inspection work scope provided by VEPCO to facilitate the discussion is provided as Enclosure 2. A list of participants in the call is included as Enclosure 3.
This completes our effort under TAC No. MB4773 and the TAC is closed.
If you have any questions, please call me at (301) 415-1448.
Sincerely,
/RA/
Gordon E. Edison, Senior Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation
Enclosures:
As stated Docket No. 50-281 cc w/ encl: See next page DISTRIBUTION:
PUBLIC LLund EDunnington OGC BFu KKarwoski PDII-1 R/F ASmith KLandis, RII ACRS CLauron Mlesser HBerkow GEdison JTsao CKhan GMcCoy DOCUMENT NAME: C:\ORPCheckout\FileNET\ML021440045.wpd Accession Number: ML021440045(Letter)
OFFICE PM:PDII-1 LA:PDII-2 SC:PDII-1 NAME GEdison EDunnington JNakoski DATE 05/22/02 05/22/02 05/22/02 OFFICIAL RECORD COPY
SUMMARY
OF CONFERENCE CALL WITH VIRGINIA ELECTRIC AND POWER COMPANY REGARDING THE REFUELING OUTAGE STEAM GENERATOR INSPECTION RESULTS AT SURRY UNIT 2 The NRC staff participated in a conference call with Virginia Electric & Power Company (VEPCO) on April 17, 2002. The purpose of the conference call was to discuss the steam generator (SG) inspection results from the Spring 2002 refueling outage at Surry Unit 2. At the time of the call, the licensee had completed the SG inspection.
Topics discussed during this call included the inspection scope, the eddy current data analysis results, plugging and repair plans and actions taken in response to the Indian Point Unit 2 (IP2) tube rupture event and NRC Information Notice 2000-02 (IN 2002-02), Recent Experience with Plugged Steam Generator Tubes. The details of the inspection scope are contained in the inspection summary VEPCO provided in support of this call. In addition to the information presented in the summary, the inspection scope included a visual inspection of all the plugs in the A SG and the search for and removal of loose parts in all SGs.
The licensee plugged one tube as the result of 23% through-wall anti-vibration bar (AVB) wear.
Although the licensees technical specification plugging limit is 40% through-wall, the licensee uses an administrative through-wall percentage of 30%. Accounting for this administrative criterion and factoring in the growth rate of the indication combined with the planned operating interval between inspections, the licensee elected to plug this tube.
In addition to AVB wear, the licensee identified minor denting at the 6th and 7th tube support plates (TSPs). The voltages of these dents ranged from 2 to 8 volts. The licensee characterized these dents as minor because a nominal-sized probe passed through the dented tubes without difficulty. The staff inquired about the licensees technique for determining the existence of flaws within tube dents. The licensee indicated that a dent is deemed free of defects if two consecutive inspections (with bobbin and/or rotating pancake coil (RPC) probe) provide data that the dent indication has not changed or that a flaw indication cannot be confirmed with an RPC probe. The licensee further explained that if the voltage of a dent indication changes by 1/4 volt as measured with a bobbin probe, then the licensee further examines that indication with an alternate probe such as an RPC probe. The licensee expressed confidence in this criterion and stated that most of the dents have been inspected with an RPC probe, which should detect flaws within these dents, and that the chances are remote that circumferential flaws would develop because the dent sizes are small. The staff acknowledged the licensees explanation, but informed the licensee of industry experience with the existence of axial and circumferential flaws within arrested dents (i.e., dents with stable voltages).
In previous outages, the licensee identified pit indications in the A and C SGs on the cold-leg, above the tube sheet secondary face. The licensee inspected a sample of 200 tubes located in the cold-leg, +/- 1 inch from the top of tube sheet transition. The licensee did not identify additional pit-like indications.
Enclosure 1
The staff requested the licensee to provide information on the performance of other inspection activities related to SG integrity. The following table summarizes the licensees response to this request.
Inspection Activity Assessment Primary to Secondary None Leakage Secondary-Side None Hydrostatic Testing New Inspection Findings None X-probe Usage None In-Situ Pressure Testing None Tube Pulls None Condition Monitoring Tube integrity met Operational Assessment Tube integrity for Next Cycle maintained Because the licensee did not identify any primary-to-secondary leakage, secondary-side hydrostatic testing was not required. In addition, the licensee did not identify new inspection findings or significant indications that warranted in-situ pressure testing or pulling tubes for destructive examination. In terms of overall SG tube integrity, the licensee indicated that their evaluations demonstrate the preservation of tube integrity for the next operating cycle.
Based on the information provided during the conference call, the staff did not identify any issues requiring further discussion.
Participants in Conference Call with VEPCO on April 17, 2002 to Discuss Steam Generator Inspection at Surry Unit 2 Name Organization G. Edison NRC A. Smith NRC J. Tsao NRC B. Fu NRC C. Lauron NRC C. Khan NRC K. Karwoski NRC M. Lesser NRC G. McCoy NRC G. Miller VEPCO L. Spain VEPCO J. Eastwood VEPCO D. Dodson VEPCO E. Brennan VEPCO R. Beger VEPCO B. Garber VEPCO Enclosure 3
Mr. David A. Christian Surry Power Station Virginia Electric and Power Company cc:
Ms. Lillian M.Cuoco, Esq. Office of the Attorney General Senior Nuclear Counsel Commonwealth of Virginia Dominion Nuclear Connecticut, Inc. 900 East Main Street Millstone Power Station Richmond, Virginia 23219 Building 475, 5th Floor Rope Ferry Road Mr. Stephen P. Sarver, Director Rt. 156 Nuclear Licensing & Operations Support Waterford, Connecticut 06385 Innsbrook Technical Center Virginia Electric and Power Company Mr. Richard H. Blount, II 5000 Dominion Blvd.
Site Vice President Glen Allen, Virginia 23060-6711 Surry Power Station Virginia Electric and Power Company Mr. David A. Heacock 5570 Hog Island Road Site Vice President Surry, Virginia 23883-0315 North Anna Power Station Virginia Electric and Power Company Senior Resident Inspector P. O. Box 402 Surry Power Station Mineral, Virginia 23117-0402 U. S. Nuclear Regulatory Commission 5850 Hog Island Road Mr. William R. Matthews Surry, Virginia 23883 Vice President - Nuclear Operations Virginia Electric and Power Company Chairman Innsbrook Technical Center Board of Supervisors of Surry County 5000 Dominion Boulevard Surry County Courthouse Glen Allen, Virginia 23060-6711 Surry, Virginia 23683 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation P. O. Box 1197 Richmond, Virginia 23209 Robert B. Strobe, M.D., M.P.H.
State Health Commissioner Office of the Commissioner Virginia Department of Health P.O. Box 2448 Richmond, Virginia 23218