ML19350A676
| ML19350A676 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 02/27/1981 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Oprea G HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 8103160640 | |
| Download: ML19350A676 (1) | |
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$11 RYAN Pt.AZA oRIVE. SulTE 'C00 Astinatos. Texas :soti State February 27,1987 Docket Nos. 50 498
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'S, " gu,D*'N ;y ATTN: Mr. G. W. Oprea, Jr.
Executive Vice President "8
N' Post Office Box 1700 A/
g-g V Houston, Texas 77001 Gentiemen:
This IE Infomation Notice is provided as an early notificatien of a possibly significant matter and it is expected that recipients will review the infoma-mation for possible applicability to their facilities.
No response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Sulletin will be issued to further recommend or recuest specific licensee acti ons.
If ycu have questions regarding this matter, please contact the Director of the appropriate NRC Regicnal Office.
Sincerely, i
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Karl V. Seyfrit. / /
Director
Enclosures:
1.
IE Information Notice No. 81-04 2.
List of Recently Issued IE Infomation Notices 8103160 WO p
SSINS No.: 6835 Accession No.:
8011040265 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 IE Information Notice No. 81-04 February 27, 1931 Page 1 of 2 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 reveal 3d 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 sufety 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 'xamination on the pipe I.D. surface of the weldment nearest the containment per,
- ration established that the cracking extended about 120 F around the fitti.
ounterbore between the 4 o' clock to 8 o' clock position.
Cracking was also e
'rved in the weld counterbore at the opposite end of the T-fitting during vi examination of the piping interior.
Radio-graphic examination of "B" and 'N nain steam line T-fitting welds disclosed crack indications at similar local s.
Metallurgical specimens of the crackiiiu were trepanned from the T-fitting of the "A" main steam iine for analysis.
Controlled excavation and depth measurements of the crack at its mid-lengt indicated a crack depth of about 0.090" in this location.
The cause of crat
'q has not yet been established.
'/EPC0 has planned an ultrasonic examination of similar weldments in Surry Unit 2 main steam lines utilizing " Hot Piping" ultrasonic techniques.
Preoarations 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 recommenced 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 availaole.
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IN 81-04 February 27, 1981 l
Page 2 of 2
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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.
Attachment:
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IE Information Notice No. 81-04 February 27, 1981 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-41 Failure of Swing Cf.eck 11/10/80 All power reactor Valve in the Decay Heat facilities with an Opitrating Removal System at Davis-License (0L) or Construction Besse Unit No. 1 Permit (CP) 80-42 Effect of Radiation 11/24/80 All power reactor on Hydraulic Snubber Fluid facilities with an Operating License (OL) or Construction Permit (CP) 80-43 Failures of the Continuous 12/5/80 All power reactor Water Level Monitor for facilities with an the Scram Discharge Volume Operating License (OL) at Oresden Unit No. 2 or Construction Permit (CP) 80-44 Actuation of ECCS in the 12/16/80 All power reactce Recirculation Mode While facilities with in in Hot Shutdown Operating License (OL) or Construction Permit (CP) 80-45 Potential Failure of 12/17/80 All pressurized water BWR Backup Manual Scram reactor facilities with Capability an Operating License (0L)
Construction Permit (CP) 81-01 Possible Failures of 1/16/81 All power reactor facilities General Electric Type with an Operating License HFA Relays (0L) Construction Permit (CP)
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81-02 Transportation of 1/23/81 All Radiography licensees i
Radiography Devices 81-03 Checklist for Licensees 2/12/81 All power reactor Making Notifications of facilities with an Significant Events in Operating License (OL)
Accordante with 10 CFk ? art 50.72 Enclosure
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