ML060270178
| ML060270178 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 02/21/2006 |
| From: | Bailey S N Plant Licensing Branch III-2 |
| To: | Levis W Public Service Enterprise Group |
| Bailey S N | |
| References | |
| TAC MC6279 | |
| Download: ML060270178 (5) | |
Text
February 21, 2006Mr. William LevisSenior Vice President & Chief Nuclear Officer PSEG Nuclear LLC - X04 Post Office Box 236 Hancocks Bridge, NJ 08038
SUBJECT:
SUMMARY
OF CONFERENCE CALL WITH PSEG NUCLEAR LLC TODISCUSS THE 2005 STEAM GENERATOR TUBE INSPECTIONS AT SALEM NUCLEAR GENERATING STATION, UNIT NO. 2 (TAC NO. MC 6729)
Dear Mr. Levis:
On April 21, 2005, the Nuclear Regulatory Commission (NRC) staff participated in a conferencecall with PSEG Nuclear LLC (PSEG) to discuss the steam generator inspection activities taking place at Salem Nuclear Generating Station, Unit No. 2. The call was conducted in response toan NRC letter dated March 15, 2005. PSEG had provided written responses to the NRC'squestions in preparation for the conference call. Enclosed is a brief summary of the conference call prepared by the NRC staff as well as the information provided by PSEG.If you have any questions about this material, please contact me at (301) 415-1321.Sincerely,/RA/Stewart N. Bailey, Senior Project ManagerPlant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No.: 50-311
Enclosures:
As statedcc w/encls: See next page
ML060270178OFFICELPLI-2/PMLPLI-2/LANRR/CSGB/BCLPLI-2/BCNAMESBailey: cmCRaynorAHiser*DRobertsDATE2/14/062/09/0612/15/052/21/06*concur my memo Salem Nuclear Generating Station, Unit No. 2 cc:
Mr. Michael GallagherVice President - Eng/Tech Support PSEG Nuclear
P.O. Box 236 Hancocks Bridge, NJ 08038Mr. Dennis WinchesterVice President - Nuclear Assessment PSEG Nuclear
P.O. Box 236 Hancocks Bridge, NJ 08038Mr. Thomas P. JoyceSite Vice President - Salem PSEG Nuclear
P.O. Box 236 Hancocks Bridge, NJ 08038Mr. George H. GellrichPlant Support Manager PSEG Nuclear
P.O. Box 236 Hancocks Bridge, NJ 08038Mr. Carl J. FrickerPlant Manager PSEG Nuclear - N21
P.O. Box 236 Hancocks Bridge, NJ 08038Mr. Darin BenyakDirector - Regulatory Assurance PSEG Nuclear - N21
P.O. Box 236 Hancocks Bridge, NJ 08038Jeffrie J. Keenan, EsquirePSEG Nuclear - N21
P.O. Box 236 Hancocks Bridge, NJ 08038Lower Alloways Creek Townshipc/o Ms. Mary O. Henderson, Clerk Municipal Building, P.O. Box 157 Hancocks Bridge, NJ 08038Dr. Jill Lipoti, Asst. DirectorRadiation Protection Programs NJ Department of Environmental Protection and Energy CN 415 Trenton, NJ 08625-0415Mr. Brian BeamBoard of Public Utilities 2 Gateway Center, Tenth Floor Newark, NJ 07102Regional Administrator, Region IU.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406Senior Resident InspectorSalem Nuclear Generating Station U.S. Nuclear Regulatory Commission Drawer 0509 Hancocks Bridge, NJ 08038
SUMMARY
OF CONFERENCE CALL PSEG NUCLEAR LLCSALEM NUCLEAR GENERATING STATION, UNIT NO. 2STEAM GENERATOR INSPECTION RESULTSSPRING 2005 REFUELING OUTAGEOn April 21, 2005, the Nuclear Regulatory Commission (NRC) staff participated in a conferencecall with PSEG Nuclear LLC (the licensee) to discuss ongoing steam generator (SG) inspection activities at Salem Nuclear Generating Station (Salem), Unit No. 2. The call was conducted in response to an NRC letter to the licensee dated March 15, 2005. The licensee provided writtenresponses to the questions outlined in the NRC letter to support the conference call. Thelicensee's responses are provided in Enclosure 2. The discussion topics included the SG tube inspection scope, results, and other related SG activities. This summary focuses on those topics where the NRC staff required additional clarification.Salem Unit No. 2 has four Westinghouse Model 51 SGs. Each SG contains approximately3400 m ill-annealed Alloy 600 tubes. Each tube has a nominal outside diameter of 0.875 inchesand a nominal wall thickness of 0.050 inches. The tubes were explosively expanded (WEXTEX) at both ends for the full length of the tubesheet and are supported by a number ofdrilled-hole carbon steel tube supports. The NRC staff asked the licensee to expand on its response to Question 1 pertaining toprimary-to-secondary leakage. The licensee indicated that leakage was estimated to be on the order of 0.01 gallons per day based upon activity levels identified on a condensate polisher resin sample. The licensee indicated that this leakage estimate was not based upon an approved method identified in the Electric Power Research Institute (EPRI) primary-to-secondary leak guidelines. The licensee also explained that periodic SG blowdown samples with detectable activity have been identified in the past. The licensee believes that these resultfrom past leakage in the SG and are not necessarily indicative of a current leak. Finally, the licensee stated that secondary system tritium levels are their principle means of detectingprimary-to-secondary leakage. Secondary system tritium levels remained below backgroundthroughout the past operating cycle. The staff also asked the licensee to expand upon its response to Question 4 pertaining to SGinspection scope (specifically regarding detection of crack-like indications at wear indications) and for dings/dents in colder regions of the SG tubes (beyond the 04H tube support). Thelicensee indicated that rotating pancake coil (RPC) (using +Point TM) inspections of bobbin coilindications of wear or cold leg thinning occur under three conditions: (1) upon detection of a new indication; (2) if the indication is pluggable; or (3) if the indication experiences a significant growth rate (>20% through-wall from the last inspection). The licensee had not finishedEnclosure 1 identifying the current population of anti-vibration bar (AVB) wear indications that would be RPCinspected at the time of the phone call, but expected about 25 new and 9 pluggable AVB wearindications would meet their RPC inspection criteria. Regarding RPC inspection of dents and dings, the licensee indicated that they follow the EPRI SG inspection guideline pertaining tocritical areas for RPC inspection of dings and dents for crack-like indications. The licensee's critical area is a function of temperature and dent voltage with the majority of inspection focusing on dents occurring at the 01H to 04H tube support plates. No cold leg dent or ding RPC inspections were in the current inspection scope. The licensee indicated that it has typically only identified cracking at dents at the 01H and 02H tube supports. Inspection scope includes the 03H and 04H tube supports to ensure a conservative inspection buffer zone based on plant operating experience. Further, the licensee indicated that the only cracking at cold legdents in other plants with Series 51 SGs occurred in a plant with much more degradation at thetube-support intersections. The licensee felt that its inspection scope adequately ensured tube integrity.In response to the NRC staff's Question 5 regarding the number and type of indicationsidentified in the most recent SG inspection, the licensee provided a preliminary summary tableof repairable indications and a sample of the eddy current information for the indications identified. The licensee indicated that no new types of degradation were identified at the timethe call was conducted. In addition, the amount of degradation was consistent withexpectations. The licensee also stated that all the indications identified at tube-support plateswere coincident with dents that had a voltage range of 1.3 volts to 4.7 volts. The indications at dents were confined to the 01H and 02H supports. The licensee stated that the number of indications identified in the tubesheet region was consistent with its past experience. The staff noted that the licensee will perform RPC inspection on a smaller percentage of wearscar, dent, and ding locations than many other licensees. The staff noted that crack-like indications coincident with wear scars have been identified at other plants. The staff also noted that the location of stress-corrosion cracking at dings or dents can not always be predicted based on temperature alone, since tube material and tube stress also influence cracking susceptibility. This consideration has led many licensees to inspect all dented and dingedlocations above a specific voltage threshold with RPC probes to confirm the absence of cracking at these locations. The staff did not identify any issues that warrant follow-up at the time of the call. Additionalreview of the issues discussed above may be performed when the staff reviews the licensee's SG inspection summary reports that will be submitted in accordance with the TechnicalSpecifications.