ML20024H486
| ML20024H486 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 05/24/1991 |
| From: | Jabbour K Office of Nuclear Reactor Regulation |
| To: | Hairston W GEORGIA POWER CO. |
| References | |
| GL-88-01, GL-88-1, TAC-80424, NUDOCS 9106040151 | |
| Download: ML20024H486 (3) | |
Text
.-
8 May 24, 1991 Docket No. LO.X 6 DIS 1RIBUT10N:
bockeFT W OGC, Ir,pjg i
NRC & Local PORs LReyes, Ril Mr. W. G. Hairston, 111 PD!l.3 R/F P!ngram Senier Vice President Fatch R/F Nuclear Operaticns SVarga Georgia rewer Company CLainas P. O. Box 1295 KJabbour Birmingham, Alabar a 35201 CYCheng, 704 EJordan, MNf*3701
Dear Mr. Hairston:
ACRS (10), P-315 SUDJECT:
EVALUATION OF INDICA 110hs IN FLEDWATLR ULLD 2B21 1FW 1?AA HATCH NUCLEAR PLANT, UNIT 2 (TAC NO. 80424)
Cy letter dated Fay 20, 1991, you inforned the NRC that during the Hatch Unit 2 refueling outage in the Spring of 1991, you identified circumferential weld 2021 1FW.12AA.9 as having three flows that are axially oriented. This weld is located on the feedwater inlet piping, opstream of the therinal sleeve annulus.
The held raterial is loconel 182 and joins an Inconel 600 safe end to en Inconel CCO :,afe-end extension. The flaw indications origirzated near or in the root of the weld and terminated in the weld material on the safe.end extension side. Quantification as to whether the crack originated in the base rnaterial near the-root of-the weld or in the out of the weld is tiot readily obtainable because the precise location of the root is ultrasonically indetettninate in the area of the indications.
In accordance with Generic Letter (GL) 88 01, you, with the assistance of your contractor Structural Integrity Associstes, corpleted the evaluations of the flaws and a weld overlay repair design. The flaws were enluated as if they resulted from intergranular stress corrosion cracting which would conservatively bound their t<havior even ',f they were due to other possible causes such as thermal fatigue cr fabrication defect. You have determined that these flaws did not present a significant structural concer n, even if they were through wall, because they are axially oriented. Ucbever, based on ASME Section XI and the guidance provided in NUREG.0313, Revision 2, repair was considered n2cessary.
Thus, you performed the repair via a standard weld overlay.
The NRC staff has leviewed the l'ay 20, 1991, submittal, and agrees with your j
conclusions that the weld repair is conservative for this case and the structural integrity of the safe.end to the safe.cnd extension weld will be l
maintained. The safety evaluation which provides the basis for the above conclusion will be transmitted to you at a later date.
Sincerely, original signed by Kahtan N. Jabbour, Project Manager 9106040151 910524 Project Directorate 11-?
PDR ADOCK 05000366 Division of Reactor projects. 1/11 P
PDR Office of Nucl(br Reactor Regulation cc: See next page f
- LA:PDll U ~O ~ctr a17RITD1T.~3((f::L'C':lhG'~~ IDIPD1T-x u
- wm!v 0FC rf:
......:.......-........:............. :..............:.......-- r / :
NAME
- R!ngrarN
- KJabbour:tw
- CYCheng
- DMatthews[
d DATE
- 05/fi91
- 05/M/91
- 05/t4/91
- 05/tA/91 s l 0 OT U tl7f E G W ED}Y "g p g" g~ "[ "n h" g jW a7 c
Docur4ni Name: FW WELD REPA1R EVALUATION
g i
f h' h [ f C s UNITFD STATES j i NUCl. EAR REGULATORY COMMISSION 5\\V WA5mN(MON O C MM
%..../
May 24. 1991 Docket No. 50-366 Mr. W. G. Hairston, !!!
Senior Vice President Nuclear Operations Georgio Pcher Corrpany P. O. Box 1295 Birmirigham, Alabama 35201
Dear I:
r, Fairston:
SUCJECT:
EVALUATIO!! Of ihDICAT10NS IN rEEDWATER WELD 2B21-1FW-12AA HATCH NUCLEAR PLANT, UNIT 2 (TAC NO. 80424)
By "HL-1636, Forwards Info Re IGSCC Susceptible Welds Per Commitments to Generic Ltr 88-01 & [[NUREG" contains a listed "[" character as part of the property label and has therefore been classified as invalid.,Rev 2.Rev 0 to SIR-91-028, Evaluation & Repair of Flaw Indications in Feedwater Safe- End a to Extension Weld at Hatch Unit 2, Also Encl|letter dated May 20, 1991]], you informed the NRC that during the Hatch Unit 2 refueling outage in the Spring of 1991, you identified circumferential keld 2B21-1FW-12AA-9 as having three flaws that are axially criented. This weld is located on the feedwater inlet piping, upstrean of the therfral sleeve annulus.
The weld traterial is le tcr.el 182 and joins an inconel 600 safe-end to an Inconel 600 safe-end extension. The flaw irdications originated near or in the root of the weld and terriirated in the weld material on the safe-end extension s i ri. (uontification as to whether the crack originated in the base uaterial cear the root of the weld or in the root of the weld is not readily obtainable because the precise location of the root is ultrasonically indeterminute in the area of the indications.
In accordance with Generic Letter (GL) 88-01, you, with the assistance of your contractor Structural Integrity Associates, ccropleted the evaluaticos of the flaws ard a weld overlay repair design.
The flaws were evaluated as if they resulted from intergrarular stress corrosion cracking which would conservatively bound their behavior even if they were due to other possibic causes such as thermal fatigue or fabrication defect.
You have deterrained that these flews did not present a significant structural concern, even if they were through wall, because they are axially oriented.
However, based on ASME Section XI and the guidance provided in NUREG-0313, hesision 2, repair was considered necessary.
Thus, you performed the repair via a standard weld overlay.
The NRC staff has reviewed the l'ay 20, 1991, submittal, and agrees with your conclusior s that the weld repair is conservative for this case and the structural integrity of the safe-end to the safe-end extension weld will be maintained. The safety evaluation which provides the basis for the above conclusion will be transmitted to you at a later date.
Sincerely,
}&Jh pl.)a[;[w Echten N. Jabbour, Project ! tanager Project tirectorate !!-3 Divisier of Reactor Projects - t/11 Office of Nuclear Peactor Regulation cc: See next page
Mr. W. G. Hairston, !!!
Edwin 1. Hetch Nuclear Plant, Georgia Power Company Units Nos. I and 2 cc:
Mr. Ernest L. Blake, Jr.
Mr. R. P. Mcdonald Shaw, Pittman, Potts and Trowbridge Executive Vice President -
2300 N Street, N.W.
Nuclear Operations Washington, D.C.
20037 Georgia Power Company P.O. Box 1295 Mr. J. T. Beckham Birm; ghAm. Alabama 35201 Vice Piesident - Plant Hatch Georgia Power Company Mr. Alan R. Herdt, Chief P.O. Box 1295 Project Branch a3 Birmingham, Alabama 35201 U.S. Nuclear Regulatory Commission 101 Marietta Street, NW, Suite 2900 Mr. 5. J. Bethey Atlanta, Georgia 30323 Manager Licensing - Hatch Georgia Power Company Mr. Dan Smith P.O. Box 1295 Program Director of Birmingham, Alabama 35201 Power Production Oglethorpe Power Corporation Mr. L. Sumner 100 Crescent Centre General Manager, Nuclear Plant Tucker, Georgia 30085 Georgia Power Cor'pany Route 1, Box 439 Charles A. Patrizia, Esq.
Baxley, Georgia 31513 Paul, Hastings, Janofsky & Walker 12th Floor Resident inspector 1050 Connecticut Avenue, N.W.
U.S. Nuclear Regulatory Commission Washington, D.C.
20036 Route 1, Box 725 Baxley, Georgia 31513 Regional Administrator, Region !!
U.S. Nuclear Regulatory Commission 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Mr. Charles H. Badger Office of Planning and Budget Room 610 270 Washington Street, S.W.
Atlanta, Georgia 30334 Mr. J. Leonard Ledbetter, Director Environmental Protection Division Department of Natural Resources 205 Butler Street, S.C., Suite 1252 Atlanta, Georgia 30334 Chairman Appling County Commissioners County Courthouse Baxley, Georgia 31513