ML20133P220
| ML20133P220 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 08/01/1985 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Beckham J GEORGIA POWER CO. |
| References | |
| TAC-59029, NUDOCS 8508140215 | |
| Download: ML20133P220 (3) | |
Text
August 1, 1985 D
Docket No. 50-321 DISTRIBUTION
[ Docket File 3 ACRS-10 NRC PDR RIngram L PDR GRivenbark ORB #4 Rdg Gray File Mr. J. T. Beckham, Jr.
HThompson Vice President - Nuclear Generation OELD Georgia Power Company EJorda'n P. O. Box 4545 BGrimes Atlanta, Georgia 30302 JPartlow
Dear Mr. Beckham:
We have reviewed the submittal dated July 1, 1985 from Georgia Power Company (GPC) regarding the inspection / mitigation program of reactor coolant stainless steel piping during the 1985 refueling outage at Hatch Unit 1 plant. GPC indicated that a total of 130 piping welds, including 4 unrepaired welds, will be ultrasonically inspected. Those welds were also inspected during the 1984 outage in accordance with Generic Letter 84-11 and represented all the accessible piping welds that are susceptible to intergranular stress corrosion cracking (IGSCC) in the recirculation, residual heat removal and reactor water cleanup systems. GPC further indicated that all the IGSCC susceptible piping welds will be either treated with induction heating stress improvement (IHSI) or repaired with weld overlay during the upcoming 1985 outage.
Based on the above, we conclude that the subject inspection / mitigation program proposed by GPC is acceptable with the exception of the comments provided below. Those comments, reflecting the current staff position as well as the pertinent guidelines proposed in the draf t revision 2 of NVREG-0313, were given to GPC in recent telephone conversations.
(1) The recently reported ultrasonic inspection results by the utilities have shown that the performance by the qualified UT personnel lacks uniformity and consistency. To resolve this concern, the NRC has determined that all UT personnel performing detection and evaluation should be requalified at the EPRI NDE Center. EPRI is expeditiously setting up the testing facilities for the requalification at the NDE Center and expects to be ready to implement the requalification program no later than September 15, 1985. We suggest that GPC contact the EPRI NDE Center to arrange a schedule for the requalification of the UT personnel to be used in the 1985 outage.
(2) The UT Sersonnel performing inspections of the overlay repaired welds should )e properly trained and qualified at the NDE Center, using the demonstrated procedures and techniques.
(3) For defective welds with axial indications, the current staff position recommends the application of weld overlay to provide a leakage barrier. This staff position is strengthened by the recently increased reporting of leakage from axial cracks in IHS! treated welds.
Therefore, we recomend that GPC consider overlaying the two unrepaired welds with axial indications during the 1985 outage.
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Mr. Beckham.
(4) Code IWB-3540 is being revised to take account of the low toughness associated with the flux welds and is expected to be published soon.
The staff has developed interim guidelines for allowable flaw sizes in flux welds which may be used now.
The key points of the staff interim guidelines are summarized below:
(a) The secondary stresses (mainly thermal stresses) should be included l
in the calculation of the stress ratio.
(b) The flaw size limits for the flux welds are 2/3 of the Code f
IWB-3640 allowables using stress ratios as modified by (a).
L Therefore, the unrepaired welds previoasly justified for continued service without repair may require overlay repair when reevaluated in accordance with the current staff interim guidelines.
i (5) All IHSI treated welds should be ultrasonically inspected after the treatment.
j Sincerely,
...a 3 m,m 3g Jpir.J y, ggg.
John F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing cc: See next page i
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Mr. J. T. Beckham, Jr.
Edwin I. Hatch Nuclear Plant, Georgia Power Company Units Nos. I and 2 cc:
G. F. Trowbridge, Esq.
Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, D.C.
20036 Mr. L..T.
Gucwa Engineering Department Georgia Power Company P. O. Box 4545 Atlanta, Georgia 30302 Mr. H. C. Nix, Jr., General Manager Edwin I. Hatch Nuclear Plant Georgia Power Company P. O. Box 442 Baxley, Georgia 31513 Mr. Louis B. Long Southern Company Services, Inc.
P. O. Box 2625 Birmingham, Alabama 35202 Resident Inspector U.S. Nuclear Regulatory Commission Route 1, P. O. Box 279 Baxley, Georgia 31513 Regional Administrator, Region If U.S. Nuclear Regulatory Commission, 101 Marietta Street, Suite 3100 Atlanta, Georiga 30303 Mr. Charles H. Badger.
f-Office of Planning and Budget
(
Room 610 270 Washington Street, S.W.
Atlanta, Georgia 30334 Mr. J. Leonard Ledbetter, Comissioner Department of Natural Resources 270 Washington Street, N.W.
Atlanta, Georgia 30334 Chairman Appling County Commissioners County Courthouse Baxley, Georgia 31513
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