ML073240010
| ML073240010 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 11/30/2007 |
| From: | Kalyanam N NRC/NRR/ADRO/DORL/LPLIV |
| To: | Walsh K Entergy Operations |
| Kalyanam N, NRR/DORL/LPL4, 415-1480 | |
| References | |
| TAC MD6351, W3-ISI-004 | |
| Download: ML073240010 (5) | |
Text
November 30, 2007 Mr. Kevin T. Walsh Vice President of Operations Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093
SUBJECT:
WATERFORD STEAM ELECTRIC STATION, UNIT 3 - REQUEST FOR ADDITIONAL INFORMATION ON THE REQUEST FOR ALTERNATIVE W3-ISI-004, PROPOSED ALTERNATIVE TO SECOND INTERVAL INSERVICE INSPECTION EXAMINATIONS (TAC NO. MD6351)
Dear Mr. Walsh:
By letter dated August 7, 2007 (Agencywide Documents Access and Management System Accession No. ML072220121), Entergy Operations, Inc. submitted an application for Request for Alternative W3-ISI-004, Proposed Alternative to Second Interval ISI [Inservice Inspection]
Examinations. Pursuant to paragraph 50.55a(a)(3)(ii) of Title 10 of the Code of Federal Regulations, Entergy proposed an alternative to the code requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, IWA-2430(a) and IWB-2500(a), for seven dissimilar metal welds in the reactor coolant system cold-leg piping.
After reviewing your request, the U.S. Nuclear Regulatory Commission staff has determined that additional information is needed to complete the review. We discussed the enclosed request for additional information (RAI) with your staff by telephone on November 19, 2007, and they agreed to provide a response to the RAI by December 11, 2007.
If you have any questions, please contact me at (301) 415-1480.
Sincerely,
/RA/
N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-382
Enclosure:
RAI cc w/encl: See next page
- No substantial change to input memo OFFICE NRR/LPL4/PM NRR/LPL4/LA DCI/CPNB/BC NRR/LPL4/BC NAME NKalyanam JBurkhardt TChan*
THiltz DATE 11/30/07 11/30/07 11/19/2007 11/30/07
November 2007 Waterford Steam Electric Station, Unit 3 cc:
Senior Vice President Entergy Nuclear Operations P.O. Box 31995 Jackson, MS 39286-1995 Senior Vice President and COO Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Vice President, Operations Support Entergy Services, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Site Vice President Waterford Steam Electric Station, Unit 3 Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 General Manager, Plant Operations Waterford Steam Electric Station, Unit 3 Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Director, Nuclear Safety & Licensing Entergy Services, Inc.
440 Hamilton Avenue White Plains, NY 10601 Director, Nuclear Safety Assurance Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Senior Manager, Nuclear Safety
& Licensing Entergy Services, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Manager, Licensing Entergy Operations, Inc.
17265 River Road Killona, LA 70057-3093 Mr. Timothy Pflieger Environmental Scientist - Supervisor REP&R-CAP-SPOC Louisiana Department of Environmental Quality P.O. Box 4312 Baton Rouge, LA 70821-4312 Parish President Council St. Charles Parish P.O. Box 302 Hahnville, LA 70057 Chairman Louisiana Public Services Commission P.O. Box 91154 Baton Rouge, LA 70825-1697 Mr. Richard Penrod, Senior Environmental Scientist/State Liaison Officer Office of Environmental Services Northwestern State University Russell Hall, Room 201 Natchitoches, LA 71497 Resident Inspector Waterford NPS P.O. Box 822 Killona, LA 70057-0751 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011
REQUEST FOR ADDITIONAL INFORMATION ON THE REQUEST FOR ALTERNATIVE W3-ISI-004 DEFERRAL OF WELD EXAMINATIONS WATERFORD STEAM ELECTRIC STATION, UNIT 3 ENTERGY OPERATIONS, INC.
DOCKET NUMBER 50-382 1.
MRP-109 utilizes a crack growth rate with a stress intensity threshold value of 9 MPa-m0.5. MRP-109 evaluations were limited to flaws with aspect ratios of 2:1 and 6:1. Larger aspect ratio flaws, up to 21:1 have been identified during examinations of other dissimilar metal welds. The flaws assumed in MRP-109 to achieve a 1 gallon per minute (GPM) leak rate may not be indicative of a realistic flaw shape and, therefore, may overly predict the time from a 1 GPM leak until failure of the weld.
Therefore, alternate analyses other than MRP-109 are necessary to support the conclusions made in the proposed alternative W3-ISI-004. Please provide results from the advanced finite element analysis, regarding predicted flaw shapes and growth.
2.
As residual stress is as important as operating temperature for flaw initiation and growth, please address the estimated residual stress in the welds and how this level of stress affects susceptibility to primary water stress-corrosion cracking. Please provide weld fabrication details and any documented repairs made to the nozzle welds and any other details which could affect the weld residual stress profile for those welds which examination deferral is requested.
3.
Can any of the welds be made to achieve at least a 90 percent American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code), Appendix VIII ultrasonic examination coverage through grinding or machining the weld surface to change the profile and allow for satisfactory ultrasonic transducer contact with the surface?
4.
Have any of the other reactor coolant pump suction or discharge or safety injection tie to reactor coolant loop dissimilar metal welds been examined using ASME Code,Section XI, Appendix VIII methods? If so, what percentage of coverage was obtained and what were the results?
5.
How much radiological dose is estimated to install the seven weld overlays during the 15th refueling outage (RF15)? How many additional welders and nondestructive examination personnel would be required to maintain personnel dose to within site as-low-as reasonably achievable (ALARA) limits? What are the site ALARA limits?
6.
Have vendors been contacted to determine the welding resources available for application of the seven additional weld overlays during RF15? What vendors were contacted, and what welding resources are available?
7.
How much time would it take to engineer the seven weld overlays? How much time would it take a vendor to develop mock-ups and qualify procedures, equipment, and personnel? Please provide the basis for the estimates.
8.
What are the thicknesses of the seven welds, and what is the range of overlay thicknesses qualified under the Performance Demonstration Initiative procedures?
9.
What duration outage extension is estimated to permit installation of preemptive structural weld overlays on the seven welds? Please provide the basis for the estimates.
10.
Please revise the commitment to submit a request for alternative, and commit to either examine the welds with an ultrasonic method acceptable to the NRC or to install a structural weld overlay on the welds during the Waterford 3 16th refueling outage.