ML20044F608
| ML20044F608 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 05/20/1993 |
| From: | Milano P Office of Nuclear Reactor Regulation |
| To: | Richard Anderson CAROLINA POWER & LIGHT CO. |
| References | |
| TAC-M81880, TAC-M82283, NUDOCS 9305280309 | |
| Download: ML20044F608 (3) | |
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UNITED STATES i
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NUCLEAR REGULATORY COMMISSION l
e WASHINGTON, D.C. 20E85-0001 l
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i May 20, 1993 Docket Nos. 50-325 and 50-324 i
Mr. R. A. Anderson Vice President
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Carolina Power & Light Company Brunswick Steam Electric Plant Post Office Box 10429 Southport, NC 28461
Dear Mr. Anderson:
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SUBJECT:
ULTRASONIC EXAMINATION OF FEEDWATER N0ZZLE N4D, BRUNSWICK STEAM-ELECTRIC PLANT, UNITS 1 AND 2 (TAC NOS. M82283 AND M81880) j i
In a letter dated January 7, 1991, Carolina Power & Light Company (CP&L) submitted the information from the nondestructive examination of the feedwater j
nozzles and_ safe ends performed during the 1990-1991 refueling outage
.i (Reload 7) at the Brunswick Steam Electric Plant, Unit 1.(BSEP-1).. Because a' potential crack indication was found-in this examination, a. meeting was held
-i on May 23, 1991, to discuss the ultrasonic test.(UT) indication.. Also, your!
l staff stated that data from the crack arrest verification system '(CAVS). would
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be used to monitor crack growth rate conditions in the reactor coolant system.
Subsequent to this meeting, the Nuclear Regulatory Commission requested, during a telephone conversation on August 8, 1991, that CP&L periodically i
provide the crack growth rate data for the Inconel 182 specimen from the_CAVS, i
after analysis and comparison to the maximum projected growth rate.
In i
letters dated September 10 and November 27, 1991 CP&L also provided ' details of the evaluation of'the UT indication, derivation of the crack growth rate law, and the stress summation assumed in the growth prediction. ' While i
suspecting that the indication was a fabrication defect rather than 1
intergranular stress corrosion cracking (IGSCC), CP&L stated that the crack-i growth analyses results showed that the UT indication would be acceptable for
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an 18-month operating cycle. CP&L stated that it planned to inspect,
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evaluate, and repair the. weld joint, if necessary, during the next scheduled -
-refueling outage.. By le.tter dated December 11, 1991, the NRC staff =provided CP&L with its conclusichtthat there was reasonable assurance that the y
- structural integrity of-the weld would be maintained and that:BSEP-1 could continue to operate until the next refueling outage scheduled,-at that time, for September 1992. The NRC also confirmed CP&L's commitments with regard to
-i the monitoring and' analyses of.CAVS data.
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In a' letter dated November 23,'1992, CP&L provided information concerning UT.
examinations of-the feedwater nozzle weld joint performed between July 13 and:23, 1992. The weld joint was examined with an automated UT system that used 45' and 60* refracted longitudinal wave and 45' shear wave units. A manual-UT technique. incorporating refracted _ longitudinal, shear wave, and -
inside diameter creeping wave search units was also used to confirm the_ size
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May 20, 1993 Mr. R. A. Andersor. of the indication and to verify that the mid-wall indication was not affected l
by the inside diameter surface of the pipe. Since there was no discernible change in the indication and it was not associated with the inside surface of the safe end, the results showed that the UT indication was no longer considered to be a potential IGSCC indication. The indication was considered to be a mid-wall discontinuity associated with a original fabrication weld repair.
l After reviewing the information provided with the letter of Novemb r 23, 1992, the NRC staff concurs with your re-categorization of the weld indication in the N4D feedwater nozzle as a NUREG-0313 Category D weld joint.
Based on this re-categorization and the scheduled removal of this weld joint in refueling outage 9, the NRC staff also finds your requests to (a) discontinue the CAVS autoclave, specifically for crack growth in this weld joint, and (b) conduct no additional examinations on this weld before replacement are acceptable.
If you have any questions, please contact me at 301-504-1457.
Sincerely, ORIGINAL SIGNED BY:
Patrick D. Milano, Senior Project Manager Project Directorate 11-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc:
See next page DISTRIBUTION:
Docket File P.D. Milano W.H. Koo 7-D-4 NRC/ Local PDRs C.E. Carpenter OGC PD 11-1 Reading File P.D. Anderson ACRS (10)
S.A. Varga J.E. Richardson 7-D-26 J.R. Johnson R-Il G.C. Lainas J. Strosnider 7-D-4 D.M. Verrelli R-Il E.G. Adensam G. Johnson 7-D-4 E.W. Merschoff R-II D:k21:DRPE 0FC
,LA:PD21:DRPE PM:PD21:DRPE C:EMCB NAMEjkDAnderso N PDMilano:t$
JStrosnider*
EGMsam DATE 05/ ///93 05/ti /93 05/19/93 05/ p /93
- See previous concurrence Document Name:
BRNB2283.LTR
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t Mr. R. A. Anderson-Brunswick Steam Electric Plant 1
Carolina Power & Light Company Units.1 and 2 l
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Mr. Mark S. Calvert-Mr. H. A. Cole ~.
I Associate General Counsel Special Deputy Attorney General Post.
l Carolina Power & Light Company State of North Carolina i
Post Office Box 1551 Post' Office Box 629 j
Raleigh, North Carolina 27602 Raleigh, North Carolina.27602 i
Mr. Kelly Holden, Chairman Mr. Robert P.'Gruber-Board of Commissioners Executive Director
-t Post Office Box 249 Public Staff - NCUC Southport, North Carolina 28422 Post Office Box 29520 l
Raleigh, North Carolina 27626-0520' Resident Inspector U.S. Nuclear Regulatory Commission Mr. H. W. Habermeyer, Jr.
Li Star Route 1, PO Box 208 Vice President-l Southport, North Carolina 28461 Nuclear Services Department l
Carolina Power & Light Company Regional Administrator, Region II Post Office. Box 1551 -' Mail OHS 7-U.S. Nuclear Regulatory Commission.
Raleigh, North Carolina 27602 101 Marietta St., N.W., Ste. 2900 i
Atlanta, Georgia 30323 Mr. Dayne H. Brown, Director Division of Radiation Protection i
N. C. Department of Environmental, l
Commerce and Natural Resources Post Office Box 27687 j
Raleigh, North Carolina 27611-7687 l
Mr. J. M. Brown I
Plant-Manager - Unit I
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Carolina Power & Light Company Brunswick Steam Electric Plant 1
Post Office Box 10429 -
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-Southport, North Carolina 28461 Public Service Commission
. State of South Carolina Post Office Drawer 11649 Columbia, South Carolina 29211
'I Mr. C. C. Warren Plant Manager - Unit 2 Brunswick Steam Electric Plant.
i Post Office Box 10429-Southport, North Carolina 1 28461 1
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