ML030300573

RAI, Request for Relief for Reactor Pressure Vessel Closure Head Penetration Welds. (TAC Nos. MB6379 and MB6380)

ML030300573
Person / Time
Site:	Saint Lucie
Issue date:	01/30/2003
From:	Moroney B NRC/NRR/DLPM/LPD2
To:	Stall J Florida Power & Light Co
Moroney B, NRR/DLPM, 415-3974
References
TAC MB6379, TAC MB6380
Download: ML030300573 (4)

Text

January 30, 2003 Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420

SUBJECT:

ST. LUCIE PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING REQUESTS FOR RELIEF FOR REACTOR PRESSURE VESSEL CLOSURE HEAD PENETRATION WELDS (TAC NOS.

MB6379 AND MB6380)

Dear Mr. Stall:

By letter dated September 26, 2002, Florida Power and Light Company (FPL) submitted a request for relief to use an alternate repair method for control element drive mechanism penetration welds. In addition, FPL requested relief from the requirement to perform flaw characterization.

The U.S. Nuclear Regulatory Commission staff has reviewed your submittal and finds that a response to the enclosed request for additional information (RAI) is needed before we can complete the review. This request was discussed with your staff on January 14, 2003, and Mr. George Madden agreed that a response would be provided within 30 days of issuance.

If you have any questions, please feel free to contact Eva Brown at (301) 415-2315.

Sincerely,

/RA/

Brendan T. Moroney, Project Manager, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-335 and 50-389

Enclosure:

RAI cc w/encl: See next page

ML030300573 OFFICE PDII-2/PM PDII-2/PM PDII-2/LA PDII-2/SC NAME BMoroney EBrown BClayton AHowe DATE 1/30/03 1/30/03 1/29/03 1/30/03 Mr. J. A. Stall ST. LUCIE PLANT Florida Power and Light Company cc:

Senior Resident Inspector Mr. R. E. Rose St. Lucie Plant Plant General Manager U.S. Nuclear Regulatory Commission St. Lucie Nuclear Plant P.O. Box 6090 6351 South Ocean Drive Jensen Beach, Florida 34957 Jensen Beach, Florida 34957 Craig Fugate, Director Mr. J. T. Voorhees Division of Emergency Preparedness Acting Licensing Manager Department of Community Affairs St. Lucie Nuclear Plant 2740 Centerview Drive 6351 South Ocean Drive Tallahassee, Florida 32399-2100 Jensen Beach, Florida 34957 M. S. Ross, Attorney Mr. Don Mothena Florida Power & Light Company Manager, Nuclear Plant Support Services P.O. Box 14000 Florida Power & Light Company Juno Beach, FL 33408-0420 P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Douglas Anderson County Administrator Mr. Rajiv S. Kundalkar St. Lucie County Vice President - Nuclear Engineering 2300 Virginia Avenue Florida Power & Light Company Fort Pierce, Florida 34982 P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. William A. Passetti, Chief Department of Health Mr. J. Kammel Bureau of Radiation Control Radiological Emergency 2020 Capital Circle, SE, Bin #C21 Planning Administrator Tallahassee, Florida 32399-1741 Department of Public Safety 6000 SE. Tower Drive Mr. Donald E. Jernigan, Site Vice President Stuart, Florida 34997 St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957

REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUESTS NOS. 20, 21, 30, AND 31 RELIEF FOR REACTOR PRESSURE VESSEL CLOSURE HEAD PENETRATION WELDS SAINT LUCIE PLANT, UNITS 1 AND 2 DOCKET NOS. 50-335 AND 50-389

1) Please comment on successive inspection plans for new Reactor Pressure Vessel (RPV) to control element drive mechanism (CEDM) tube pressure retaining welds, which are deposited approximately mid-wall of the RPV head. The discussion should include the types of nondestructive examination that are going to be performed and the frequency. If successive inspections are not going to be performed, provide the technical justification and basis for not performing a successive/repetitive inspection on the new pressure boundary welds.

2) Relief Requests Nos. 21 and 31 indicate that calculations, analyses and evaluations discussed within provide the technical basis why this repair methodology provides an acceptable level of quality and safety. Please submit the calculations, analyses and evaluations discussed below from Relief Requests Nos. 21 and 31:

a) American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, stress calculations will be performed to show the flaws are acceptable for a number of years.

b) An analysis of the new pressure boundary welds will be performed using a 3-dimensional model of a CEDM nozzle located at the most severe hillside orientation.

c) A primary stress analysis for design conditions will be performed. A maximum Primary General Membrane Stress Intensity (Pm) will be calculated and shown to be less than the maximum allowed by the ASME Code.

d) The maximum cumulative fatigue usage factor will be calculated, and allowable years of future plant operation will be based on the maximum allowed ASME Code usage factor criterion of 1.0.

e) A fracture mechanics evaluation will be performed to determine if degraded J-groove weld material could be left in the vessel, with no examination to size any flaws that might remain following the repair.

f) Residual stresses will not be included in the flaw evaluations since it will be demonstrated by analysis that these stresses are compressive in the low alloy steel base metal.

g) Flaw evaluations will be performed for a postulated radial corner crack on the uphill side of the RPV head penetration, where stresses are the highest and radial distance from the inside corner to the low alloy steel base metal (crack depth) is the greatest.

Enclosure

h) Fatigue crack growth, calculated for the remaining operational life, should be small, and the final flaw size will be shown to meet the fracture toughness requirements of the ASME Code using an upper shelf value of 200ksi/in for ferritic materials.