ML18130A548
| ML18130A548 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/27/1979 |
| From: | Neighbors D Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7909170469 | |
| Download: ML18130A548 (8) | |
Text
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AUG 2 7 1979 Docket No. ~~
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LICENSEE:
Virginia Electric and Power Company FACILITY:
Su~ry Power Station, Unit Nos. 1 & 2
SUBJECT:
SUMMARY
OF MEETING HELD ON AUGUST 8, 1979, TO DISCUSS FEEDWATER LINE CRACKS The subject meeting was held with VEPCO and 1~estin*ghouse to discuss the,
cracked feedwater~lines at Surry Unit l. Alis~ of attendees is attached.
H*ighl_ights of the meeting are summarized below.
On-June 22, 1979, cracking was disclosed at the reducer side of the reducer to steam generator welds by radiography in *accordance with the requirements
. of ASME Code, Secfion III. The ba'lance of reducer to steam generator nozzles on Unit l and Unit 2 were subsequently r:adiographed and cracking was dis-*
covered in all the fittings. The balance of welds in the feedwater lines of Unit l between the steam generator nozzles and the containment penetrations were radiographed.
Seven rejectahle indications were revealed by the more sensitive radiography. The indications were identified as original fabrication discontinuities.
The reducers were removed from Unit 1 and sent to iiJestinghouse for metallurgical analysis. *From the work performed to date, Westinghouse reported that the major cracks in the Loop 11B 11 reducer examfned were located at the 64° and 1210 positions with o0 located at 12 o'clock.
The de~pest crack,-;l'raS 0.080 inches with the remainder being less the 0.040 inches.
The,mode of failure was characterized as corrosion assisted fatigue by-Westinghouse.
Stress analyses were performed by t~esti nghouse on the feedwater lines. The results of the
- stress analyses indicat~ that loads w~re within th~ Code allowable limits.
The licensee* is replacing the reducers with. new fittings.
The new fittings are of the same material as the originals but with a larger radius in the counter bore transition region.
The reducer to nozzle welds will be stress relieved foMowing welding.
The licensee has removed the veryshallow indicat1ons in the nozzles by flapper wheel grinding.
The licensee is repairing the indicators found in the other welds in the feedwater lines. Radiography and u]tr.asonic inspection will be performed followina welding and stress
- relieving to establish the repairs as acc~ptabl~ andwas a baseline for future inspections. The licensee stated that radiography and ultrasonic -_*
inspections will b*e performed of the reducer-to-nozzle vicinity at the riext refueling outage.
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- U,S. GOVERN~ENT PRINTING OFFICE: 1978 - 265 - 7BO 7 9()91 7 our 19 _'!,
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' The-licensee is a member of the Westinghouse Owner's Group addressing the feed\\'1ater line cracking problem and will be cognizant of the results of the testing and anaJyses performed.
At the conclusion of the meeting, the NRC staff stated that the actions being taken by;the licensee were acceptable for restart of Unit l provided.that the follow1ng are accomplished prior to startup:
- l. The licensee should submit a report_ documenting and summarizing the inspection and repair, including the results of a 10 CFR 50.59 determination as to whether anM unreviewed safety question has*
. been introduced by the repairs. The repair should include:
- a.
The nature and extent of cracking,
- b.
an interim metall~rgical evaluation; modes of failure;
- c. a summ~ry of the stress analysis,
- d.
feedwater chemistry *inform~tion,
- e. corrective ~ctions taken~
- f.
a safety evaluation.
- 2.
RT of the reducer welds should be conducted after postweld heat treatment.
- 4.
The l icnesee should provide a commitment to conduct an*' 1RT and UT inspection of the reducer welds at the next refueling outage.
t~ addition to the above, the staff requested that the licensee pr6vide a copy of the final metallurgical report when completed.
The staff also -
requested that the licensee provide a time/temperature histo.ry of* the hot functional testing for Unit 2 as well as provide a cracked reducer from Unit 2 for ind~pendent evalu.ation by the NRC.
Original Signed By' Don ~eighbors, Project Manager Operating Reactors Branch #l Division of Operating Reactors
Attachment:
List of attendees Ct;_ w/enclosure See next page
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- 'l NRC E. Reeves R.
- I berman --
1~. Collfos T.
- L:iu R. Klecker M. Boyle C. Sellers LIST OF ATTENDEES May 8, 1979 Meeting VEPCO D. Benson R. Saunders 14ESTINGHOUSE D. Marburger
- J
- Camp be 11
- T. -Campbe 11
- 0. White I
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u.o. GOVERNMENT PRINTING c:,prpgce: 1978.. 201 "'780
Meeting Summary for Surr,y Unit l Docket.File NRC PDR Local PDR NRR Reading ORBl Reading H. Denton E. Case D. Eisenhut G. Zech W. Gammi 11 J. Miller L. Shao R. Vollmer W. Russe 11 B. Grimes T. J. Carter T. Ippolito R. Reid A. Schwencer
- o. Ziemann V. Noonan P. Check G. Lainas G. Knighton e
Chief, Systematit Evaluation Br~nch Project Manager DOR Licensing Assistant
- DELO OI&E (3)
R. Fraley, ACRS (16)
Program Support Branch TERA J. R. Buchanan NRC Participants Short Service List e
e e
UNITED STATES NUCLEAR REGULATORY COMMISSION..
WASHINGTON, D. C. 20555 August 27, 1979 Docket No. 50-280 LICENSEE:* Virginia Electric and Power Company FACILITY:
Surry Power Station, Unit N9s. l & 2 SUHJECT:
SUMMARY
OF MEETING HELD ON AUGUST 8, 1979, TO DISCUSS FEEDWATER LINE CRACKS The subject meeting was held with VEPCO and Westinghouse to discuss the cracked feedwater lines at Surry Unit 1. A list of attendees is attached.
Highlights of the meeting are summarized below.
On June 22, 1979, cracking was disclosed at the reducer side of the reducer to steam generator welds by radiography in accordance with the requirements of ASME Code,Section III. The balance of reducer to steam generator nozzles on Unit l a*nd Unit 2 were subsequently radiographed and cracking was dis-covered ilJ_all the fittings.
The balance of welds in the feedwater lines of Unit l between the steam generator nozzles and the containment penetrations were radiographed.. Seven rejectable indications.were revealed by the more sensitive_ radiography.
The indications were identified as original fabrication discontinuities.
The reducers were removed from Unit land ~ent to Westinghouse for metallurgical analysis.
From the work performed to date, Westinghouse reported that the major cracks in the Loop "B" reducer examined were located at the 64° and 1210 positions with o0 located at 12 o'clock. The deepest crack wis 0.080 inches
- with the remainder being less the 0.040 inches. The mode of failure was characterized as corrosion assisted fatigue by Westinghouse.
Stress analyses were performed by Westinghouse on the feedwater lines. The results of the stress analyses indicate that loads were within the Code allowable limits.*
The licensee is replacing th~ reducers with new fittings.. The new fittings are of the same material as:the originals but with a larger radius in the counter bore transition region.
The reducer to nozzle welds will be stress relieved following welding.
The licensee has removed the very shallow indications in the nozzles by flapper wheel grinding.
The licensee is repairing the indicators found in the other welds in the feedwater lines~
Radiography and ultrasonic inspection will be performed following welding and stress relieving to ~stablish the repairs as acceptable and as a baseline for future inspections.
The licensee stated that radiography and ultrasonic inspections wil 1 be performed of the reducer-to-nozzle vicinity at the next refueling outage.
r,.
. -* '. The licensee is a member of the Westinghouse. Owner's Group addressing the feedwater line cracking problem and will. be cognizant of the results of the
- testing and analyses performed.
At the conclusion of the meeting, the NRC staff stated that the actions being taken by the licensee were acceptable for restart of.Unit 1 provided that the following are accomplished prior to startup:
- 1.
The licensee should submit a report docume*nting and summarizing the inspection and repair, including the resul.ts of a 10 CFR 50.59 determination as to whether any unreviewed safety question has been introduced by the repairs. The repair should include:
- a. The nature and extent of cracking,
- b.
an interim metallurgical evaluation;: modes of failure,
- c. a summary of the stres.s analysis,
- d.
feedwater chemistry information,
- e.
corrective actions taken,
- f. a safety evaluation.
- 2.
RT of the reducer welds should be conducted after postweld heat treatment.
- 3.
A baseline RT and UT should be obtained.
- 4..The l i cnesee should provide a commi tmen*t to conduct an RT and UT inspection of the reducer welds at the next refueling outage.
In addition to the above, the staff requested that the licensee*provide a copy of the final metallurgical report when completed.
The staff also requested that the licensee provide a time/temperature history of the hot functional tejting for Unit 2 as well as provide a cracked reducer from Unit 2 for independent evaluation by the NRC *
Attachment:
List of attendees cc:
w/enclosure See next page
,~*,
NRC E. Reeves R. Iberman W. Collins.
T.. Liu R. Klecker M. Boyle C. Sellers LIST OF ATTENDEES May 8, 1979 Meeting VEPCO D. Benson R. Saunders e
WESTINGHOUSE D. Marburger J. Campbell T. Campbell D. White
-< r Mr. W. L. Proffitt Virginia Electric and Power Company cc:
Mr. Michael W. Maupin Hun to.n and Wi 11 i ams Post Office Box 1535 Richmond, Virginia 23213 Swem Library College of William and Mary Williamsburg, Virginia 23185 Donald J. Burke U. S. Nuclear Regulatory Commission Region II Office of Inspection and Enforcement 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 e