ML19350B257
| ML19350B257 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 02/27/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Counsil W NORTHEAST NUCLEAR ENERGY CO. |
| References | |
| NUDOCS 8103200181 | |
| Download: ML19350B257 (1) | |
Text
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FES 2 7193 Docket Nos. 50-245 50-336 gjp s M/
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Northeast Nuclear Energy Company O(tj( / (U (g ATTN: Mr. W. G. Counsil L
A Senior Vice President - Nuclear l2 43 n,
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Engineering and Operations P. O. Box 270 9
,D% p Hartford, Connecticut 06101 i
Gentlemen:
The enclosed IE I:: formation Notice No. 81-04, " Cracking in Main Steam Lines" is forsarded to you information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, rmde-Ufs
$btvl, e H. Grier otrector
Enclosures:
1.
IE Information Notice No. 81-04, with 2 attachments CCNTACT:
L. E. Tripo (215-337-5232) cc w/encis:
J. F. Opeka, System Superintendent Nuclear Operations E. J. Mroczka, Station Superintendent D. G. Diedrick, Manager of Quality Assurance J. R. Himmelwright, Licensing Safeguards Engineer 8108200 \\T\\
SSINS No.: 6835 Accession 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 20-inch piping to the safety relief valve header and 30-inch main steam line of Steam Generator "A".
This piping connection is located outsice the containment penetration immediately upstream of the main steam is lation valve as shown in the attached sketch.
A visual and dye penetrar. examination on the pipe I.D. surface of the weldment nearest the containment penetration established that the cracking extended 0
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 liaa T-fitting welds disclosed crack indications at similar locations.
Metallurgical specimens of the cracking were trepanned from the T-fitting of the "A" main steam line for analysis.
Controlled excavation and depth measurements of the crack at its mid-length indicated a crack depth of about 0.090" in this location.
The cause of cracking has not yet been established.
VEPCO.has planned an ultrasonic examination of similar weldments in Surry Unit 2 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 recipients will review the information for possible applicability to their plants.
For those plants having are currently in a refueling or f
that a ultrasonic and/or radiogr DUPLICATE DOCUMENT counterbore areas of the T-fitti operations, unless some current i
Entire document previously is available.
entered into system under:
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