ML15224A025
| ML15224A025 | |
| Person / Time | |
|---|---|
| Site: | Oconee, McGuire  |
| Issue date: | 02/27/1981 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 8103160725 | |
| Download: ML15224A025 (5) | |
Text
rSIp.R REGj S o UNITED STATES NUCLEAR REGULATORY COMMISSION REGION 11 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 FEB 2 7 1981 In Reply Refer To; RII:JPO 50- 9 0-269 50-270 50-28 Duke Power Company Attn: W. 0. Parker, Jr.
Vice President, Steam Production P. 0. Box 2178 Charlotte, NC 28242 Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter and it is expected that recipients will review the informa tion for possible applicability to their facilities. No response is requested at this time. If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to further recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appro priate NRC Regional Office.
Sincerely, J mes P. O'Reilly Di ector
Enclosures:
- 1. IE Information Notice No.
- 2. Recently Issued IE Information Notices cc w/encl:
M. D. McIntosh, Plant Manager J. C. Rogers, Project Manager J. E. Smith, Station Manager 8103160 7a9
SS*No.: 6835
/
Accc ion 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 which 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 about 1200 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 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 similar main steam line configurations which are currently in a refueling or extended repair outage, it is recommended that a ultrasonic and/or radiographic examination of the three welds and counterbore areas of the T-fittings be performed before resumption of operations, unless some current basis for assurance of piping integrity is available.
IN 4 February 27, 1981 Page 2 of 2 No response to this notice is requested at this time. If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Attachments:
- 1. Sketch
- 2. Recently issued IE Information Notices
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0 IN 81-04 RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No.
Subject Issue Issued to 81-03 Checklist for Licensees 2/12/81 All power reactor Making Notifications of facilityes with an Significant Events in OL Accordance with 10 CFR 50.72 81-02 Transportation of 1/23/81 All Radiography Radiography Devices licensees 81-01 Possible Failures of 1/16/81 All power reactor General Electric Type facilities with HFA Relays OL or CP.
80-45 Potential Failure of 12/17/80 All PWR facilities BWR Backup Manual Scram with an OL or CP Capability 80-44 Actuation of ECCS in the 12/16/80 All PWR facilities Recirculation Mode While with an OL or CP in Hot Shutdown 80-43 Failures of the Continuous 12/5/80 All power reactor Water Level Monitor for facilities with OL the Scram Discharge'Volume or CP at Dresden Unit No. 2 80-42 Effect of Radiation on 11/24/80 All power reactor Hydraulic Snubber Fluid facilities with OL or CP 80-41 Failure of Swing Check 11/10/80 All power reactor Valve in the Decay Heat facilities with an Removal System at Davis-OL or CP Besse Unit No. 1 80-40 Excessive Nitrogen Supply 11/10/80 All power reactor Pressure Actuates Safety-facilities with Relief Valve Operation to OL or CP Cause Reactor Depressur ization OL = Operating Licenses CP = Construction Permits