ML19350B247
| ML19350B247 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/27/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 8103200164 | |
| Download: ML19350B247 (1) | |
Text
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UNITED STATES y,m g
NUCLEAR REGULATORY CCMMISSION 3.';,
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7 INI Docket Nos.
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A Philadelphia Electric Ccmpany ATTN: Mr. S. L. Daltrof f U
4 Vice President
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2301 Market Street "o)
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f'V Philadelphia, Pennsylvania 19101
%t Gentlemen:
The enclosed IE Information Notice No. 81-04, " Cracking in Main Steam Lines" is forwarded to you information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, c-errl.
22&vv e H. Grier ctor
Enclosures:
1.
IE Information Notice No. 81-04, with 2 attachments CONTACT:
L. E. Triep (215-337-1232) l l
1 cc w/encls:
W. T. Ullrich, Stat'on Superintehdent Troy B. Conner, Jr., Esquire Eugene J. Bradley, Esquire Raymond L. Hovis, Esquire Michael J. Scibinico, II, Assistant Attorney General i
l B108200 M
SSINS No.: C53S Accession No.:
SC110:02c5 IN 81-04 UNITED STATES NUCLEAR REGULATORY C0vvdSSICN OFFICE OF INSpECTICN AND ENFORCEMENT WASHINGTON, D.C. 20555 February 27,1531 IE Information Notice No. 81-04:
CRACKING IN MAIN STEAM LINES Description of Circumstances:
The Virginia Electric Pcwer Ccmpany promptly rotified 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 connecticn 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 weld ent nearest the containment penetration established that the cracking extended about 120 F around the fitting counterbore between the 4 o' clock to e o'cicck 0
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 of the "A" main steam line for analysis.
Controlied excavation and depth measurements of the crack at its mid-length indicated a crack depth of about O.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" ultrastnic technicues.
Preparations are also being made to ultrasonic examine similar welc'ments at North Anna Unit 1, currently in cold shutdown for refueling.
Recom endation 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 thei:
plants.
For those plants having pg are currently in a refueling or 4
_s that a ultrasonic and/or radiogr DUPLICATE DOCUMENT k
I counterbore areas of tne T-fitti operations, unless scme current Entire dccument previously l
is available.
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No. of pages:
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