ML19350B256
| ML19350B256 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 02/27/1981 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Hovey G METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 8103200180 | |
| Download: ML19350B256 (1) | |
Text
-7 ri
- gp Rti 8
o UNITED STATES 8
NUCLEAR REGULATORY COMMISSION g "e L-REGION I
%,
- O 4((
631 PARK AVENUE KING oF PRUSSIA, PENNSY!.VANIA 19406
+....
/,
Docket No. 50-320 FEB 2 7198j s
h0,' //hcf/!/
t.\\
,/ /7 A J
Metropolitan Edison Company N
Vice President anq Director of TMI-2 6-i Al, P 2 3 ATTN: Mr. G. K. Hovey v
73gI' '3 hg Dgg%
-/
P. O. Box 480 Middletown, Pennsylvania 17057 g
- ,j
,fx
~
60 \\f 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,
%u+WI.
22&w e H. Grier a1 rector
Enclosures:
1.
IE~Information Notice No. 81-04, with 2 attachments CONTACT:
L. E. Tripp (215-337-5282) cc w/encls:
J. J. Barton, Manager Site Operations, TMI-2 E. D. Fuller, TMI-2 Licensing Supervisor E. G. Wallace, PWR Licensing Manager J.'B. Liberman, Esquire G. F. Trowbridge, Esquire Ms. Mary V. Southard,-Chairperson, Citi:: ens for a Safe Environment 8108200@D
SSINS No.: 6835 Accession No.:
8011040265 IN S1-04 UNITED STATES NUCLEAR REGULUGRY COMMISSION OFFICE OF INSPECTICN AND ENFORCEMENT WASHINGTON, D.C. 20555 February 27,1231 IE Infornation Notice No. 81-04:
CRACKING IN MAIN STEAM LINP.S Description of Circumstances:
The Virginia Electric Power Company promptly notified the NRC on Cebruary 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.O. surface of the weldment nearest the containment penetration established that the cracking extended 0
about 120 C around the fitting counterbore between tSe 4 o' clock to S o'clech position. Cracking was also observed in the weld co:.nterbore 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 locatiens.
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.
i l
l 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 ma& to ultraso-ic e,. amine 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 l
plants.
For those plants having are currently in a refueling or 9,
that a ultrasonic and/or radiogr j
DUPLICATE DOCUMENT counterbore areas of the T-fitti l
operations, unless some current Entire dccument previously l
is available.
entered into system under:
l
^=
E0//ovo21,5 No. of pages:
/,/
$Yh
$hb h&
e