ML19350B249
| ML19350B249 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/27/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 8103200171 | |
| Download: ML19350B249 (1) | |
Text
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4 jg UNITED STATES j
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NUCLEAR REGULATORY COMMISSION g
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Q 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406
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Docket No. 50-334
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FEB 271981
.T!L Duquesne Light Company ATTN: Mr. C. N. Dunn C
Vice President
/.l/;g 2 O 1991g 3_u.,,Dlgsgrg Operations Division 435 Sixth Avenue 9
Pittsburgh, Pennsylvania 15219 9
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Gentlemen:
.o The enclosed IE Infomatien Notice No. 81-04, " Cracking in Main Steam Lines" is forwarded to you information.
No written response is required.
If you desire additional informaticn regarding this matter, please contact this office.
Sincerely, Oc~w-WI.
EEAvv 1
e H. Grier sirector
Enclosures:
1.
IE Infomation Notice No. 81-04, with 2 attachments CONTACT:
L. E. Tripp (215-337-5282) cc w/encls:
F. Bissert, Technical Assistant Nuciear R. Washabaugh, QA Manager J. Werling, Station Superintendent G. Moore, General Superintendent, Pcwer Stations Department J. J. Carey, Director of Nuclear Operations R. Martin, Nuclear Engineer J. Sieber, Sup;;intendent of Licensing and Compliance, BVPS elosseo\\1\\
SSINS No.: 6835 Accassion No.:
8011040265 IN 81-04 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 February 27,1981 IE Information Notice No. 81-04:
CRACKING IN MAIN STEAM LINES Description of Circumstances:
The Virginia Electric Power Company promptly notified the NRC on February 23, 1981 that a radiography examination, durIng the ongoing steam generator replacement outage at Surry Unit 1, had revealed a lengthy crack indication in the I.D. counterbore area of a weldment on the in-line "T" fitting whi'ch connects the vertical run of 30-inch piping to the safety relief valve header and 30-inch main steam line of Steam Generator "A".
This piping connection is located outside the containment penetration immediately upstream of the main steam isolation valve as shown in the attached sketch.
A visual and dye penetrant examination on the pipe I.D. surface of the weldment nearest the containment penetration established that the cracking extended D
about 120 F around the fitting counterbore between the 4 o' clock to 8 o' clock position. Cracking was also observed in the weld counterbore at the opposite end of the T-fitting during visual examination of the piping interior.
Radio-graphic examination of "B" and "C" main steam line T-fitting welds disclosed crack indications at similar locations.
Metallurgical specimens of the cracking were trepanned from the T-fitting l
of the "A" main steam line for analysis.
Controlled excavation and depth measurements of the crack at its mid-length inoicated a crack depth of about 0.090" in this location.
The cause of cracking has not yet been established, i
VEPCO.has planned an ule. =..fc examination.of similar weldments in Surry Unit 2 l
main steam lines utilizing " Hot Piping" ultrasonic techniques.
Preparations are also being made to ultrasonic examine similar weldments at North Anna Unit 1, currently in cold shutdown for refueling.
Recommendation to Licensees:
This information is provided as an early notification of a significant safety matter that is still under review by the NRC staff.
It is expected that l
recipients will review the information for possible applicability to their plants.
For those plants having are currently in a refueling or 1
that a ultrasonic and/or radiogr i
DUPLICATE DOCUMENT i
counterbore areas of the T-fitti 4
operations, unless some current
- j Entire document previously is available.
entered into system under:
r Ro//ovo24,5 Ano No. of pages:
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