ML19208B563
| ML19208B563 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 07/12/1979 |
| From: | GULF STATES UTILITIES CO. |
| To: | |
| Shared Package | |
| ML19208B562 | List: |
| References | |
| NUDOCS 7909210015 | |
| Download: ML19208B563 (2) | |
Text
k Statement of Safety Implication:
10CFR 50.55(e)i Safety Concerns Due to a Potential Defective Weld T e existence of gross amounts of discontinuities in the K-bevel area of the ("T") weld may lead to unacceptable stresses and deformations iring the operation of the plant due to abnormal conditions and
- us could endanger the structural integrity of the building.
Descriction of the Deficiency:
10CFR 50.55(e)ii During a Stone & Webster Audit conducted of the Graver Northeast Facility, questions were raised concerning the adequacy of the Ultrasonic inspection of the T-Joint on the Containment Corner Junctio1 Assemblies. The T-Junctions had been tested earlier using a h5 Ultrasonic scan and accepted by Graver for shipment. Stone &
Webster requested that four of the T-Junction welds be retested using a h5 Ultrasonic scan. Three of the four reexaminations revealed indications of interpass cracking of the weld. Grover performed, at Stone & Webster's request, additional retesting, using a 45 and 70 Ultrasonic scan. The retest revealed numerous indications of inter-pass cracking of the weld. Additional verification test using a 0 Ultrasonic scan from the top of the starter stub plate revealed defects in h5fs of the length of the Joints.
It was concluded that the 45 Ultrasonic scan originally used by Graver, which was the basis of acceptance of the component, was inadequate to achieve a meaningful Ultrasonic examination of the T-Joint veld as required by the ASSE hpo 7909210 C [
h4 2
This deficiency appears to represent a breakdown in the Graver's QA Program in that:
1.
It did not properly determine and apply the necessary extent ar.d scope of Ultrasonic examination for the T-Joint weld.
2.
It failed to identify the defects and would have allowed the components to be shipped to the field.
E==exy 321f States Utilities is continuing its investication of the cause of this deficiency and is reviewing Graver's Quality Assurance Procedures to determine the corrective action necessary to resolve this problem. A follow up report will be provided within 60 days.
h O *.,