ML080370031

Request for Additional Information, Proposed Request for Alternative W3-R&R-006 to ASME Code Requirements for Weld Overlay Repairs for Second 10-Year Inservice Inspection

ML080370031
Person / Time
Site:	Waterford
Issue date:	02/08/2008
From:	Kalyanam N NRC/NRR/ADRO/DORL/LPLIV
To:	Walsh K Entergy Operations
Kalyanam N, NRR/DORL/LP4, 415-1480
References
TAC MD5388
Download: ML080370031 (5)

Text

February 8, 2008 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 RE: REQUEST FOR ALTERNATIVE W3-R&R-006, PROPOSED ALTERNATIVE TO ASME CODE REQUIREMENTS FOR WELD OVERLAY REPAIRS (TAC NO. MD5388)

Dear Mr. Walsh:

By letter dated April 26, 2007, Entergy Operations, Inc., submitted an application requesting the U.S. Nuclear Regulatory Commission (NRC) approval of Request for Alternative W3-R&R-006, Proposed Alternative to ASME Code [American Society of Mechanical Engineers Boiler and Pressure Vessel Code] Requirements for Weld Overlay Repairs After reviewing your request, the NRC staff has determined that additional information outlined in the enclosure is needed to complete the review. We discussed this information with your staff by telephone and they agreed to provide the additional information requested within 30 days of the receipt of this letter.

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:

Request for Additional Information cc w/encl: See next page

ML080370031 (*)No major change from Staff-provided RAI OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/DCI/CPNB NRR/LPL4/BC NAME NKalyanam JBurkhardt TChan (*) THiltz DATE 2/7/08 2/7/08 1/24/08 2/8/08 Waterford Steam Electric Station, Unit 3 (November 2007) cc:

Senior Vice President Manager, Licensing Entergy Nuclear Operations Entergy Operations, Inc.

P.O. Box 31995 17265 River Road Jackson, MS 39286-1995 Killona, LA 70057-3093 Senior Vice President and COO Mr. Timothy Pflieger Entergy Operations, Inc. Environmental Scientist - Supervisor P.O. Box 31995 REP&R-CAP-SPOC Jackson, MS 39286-1995 Louisiana Department of Environmental Quality Vice President, Operations Support P.O. Box 4312 Entergy Services, Inc. Baton Rouge, LA 70821-4312 P.O. Box 31995 Jackson, MS 39286-1995 Parish President Council St. Charles Parish Site Vice President P.O. Box 302 Waterford Steam Electric Station, Unit 3 Hahnville, LA 70057 Entergy Operations, Inc.

17265 River Road Chairman Killona, LA 70057-3093 Louisiana Public Services Commission P.O. Box 91154 General Manager, Plant Operations Baton Rouge, LA 70825-1697 Waterford Steam Electric Station, Unit 3 Entergy Operations, Inc. Mr. Richard Penrod, Senior Environmental 17265 River Road Scientist/State Liaison Officer Killona, LA 70057-3093 Office of Environmental Services Northwestern State University Director, Nuclear Safety & Licensing Russell Hall, Room 201 Entergy Services, Inc. Natchitoches, LA 71497 440 Hamilton Avenue White Plains, NY 10601 Resident Inspector Waterford NPS Director, Nuclear Safety Assurance P.O. Box 822 Entergy Operations, Inc. Killona, LA 70057-0751 17265 River Road Killona, LA 70057-3093 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Senior Manager, Nuclear Safety 611 Ryan Plaza Drive, Suite 400

& Licensing Arlington, TX 76011 Entergy Services, Inc.

P.O. Box 31995 Jackson, MS 39286-1995

4 REQUEST FOR ADDITIONAL INFORMATION WATERFORD STEAM ELECTRIC STATION, UNIT 3 REQUEST FOR ALTERNATIVE W3-R&R-006 PROPOSED ALTERNATIVE TO ASME CODE REQUIREMENTS FOR WELD OVERLAY REPAIRS TAC NO. MD5388 By letter dated April 26, 2007, Entergy Operations, Inc. (the licensee), proposed an alternative (W3-R&R-006) to the requirements of American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), for mitigating primary water stress-corrosion cracking on dissimilar metal welds using full structural weld overlays at Waterford Steam Electric Station, Unit 3. To complete its review, the Nuclear Regulatory Commission (NRC) staff is requesting the following additional information:

1. In the April 26, 2007, letter, the licensee requested NRC approval of Request for Alternative W3-R&R-006 to support the spring 2008 refueling outage (RF15).

However, the duration of the proposed alternative is not specified in the April 26, 2007, submittal other than for the spring 2008 refueling outage. Please confirm/clarify the duration of the proposed alternative. Include the dates of the current inservice inspection (ISI) interval.

2. In Section V.A.3.c of Request for Alternative W3-R&R-006, the licensee discussed the inspection issues regarding cast austenitic stainless steel (CASS) safe ends as listed in Attachment 1 of the licensees submittal dated April 26, 2007. The licensee stated correctly that the ultrasonic examination (UT) has not been qualified in accordance with Appendix VIII, Supplement 11 of the ASME Code,Section XI, in the examination of cast austenitic stainless steel. The licensee stated further that a flaw with a depth of 75 percent of pipe thickness and circumference of 360 degrees will be assumed in the crack-growth calculation for the cast stainless steel safe ends. In light of the limiting capability of the current UT technology in the CASS examination, the postulated 75 percent depth flaw may not be adequate to assess the structural integrity of the CASS component. In view of this, the licensee might consider options such as:

1. Sizing the initial flaw depth at 100 percent through-wall for the crack-growth calculations.

2. If the 100 percent through-wall flaw is impractical or creates a hardship in the overlay design or installation, assuming an initial flaw with 75 percent through-wall depth in the crack-growth calculation and adjusting inspection frequency for the inspection volume.

5 The licensee is requested to provide an approach to resolve the CASS issue in Alternative W3-R&R-006.

3. On page 6, second paragraph, of the April 26, 2007, submittal, the licensee stated that it may apply a butter (transitional) layer of austenitic stainless steel filler metal across the austenitic stainless steel base metal.

1, Discuss whether paragraph (e) of Code Case N-504-2 is applicable to the butter layer if austenitic stainless steel filler metal is applied. Paragraph (e) requires existence of certain delta ferrite content in the welded metal when austenitic stainless steel weld metal is used.

2. Identify the austenitic stainless steel weld filler metal that will be used for the butter layer.

3. Confirm that the Certified Material Test Report (CMTR) for the austenitic stainless steel filler wire shows a minimum delta ferrite of a specified amount. Please provide the maximum and minimum delta ferrite content for the heat of austenitic stainless steel filler wire to be used, as stated on the CMTR.