ML20126D384
| ML20126D384 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Waterford |
| Issue date: | 06/04/1984 |
| From: | Shao L NRC |
| To: | Peranich M NRC |
| Shared Package | |
| ML20125A430 | List:
|
| References | |
| FOIA-84-426, FOIA-84-449, FOIA-84-A-55, FOIA-84-A-65 NUDOCS 8506150065 | |
| Download: ML20126D384 (3) | |
Text
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- JUN 4 1984 MEMORANDUM FOR:
Mark Peranich, Leader Waterford Inquiry Team FROM:
L. C. Shao, Leader Civil / Structure & Piping / Mechanical Team
SUBJECT:
EVALUATION OF UNDERSIZED WELDS IN WATERFORD 3 Per your request, we have investigated licensee's disposition of construction deficiencies regarding undersized socket welds in Waterford 3 schedule 80 piping.
Our evaluation concludes that the disposition is acceptable and adequate and it is attached for your use.
@u y
Larry C. Shao, Leader C1vil/ Structure & Pipinr/ Mechanical Team
Attachment:
As stated cc:
D. Eisenhut D. Crutchfield S. Hou D. Ross G. Arlotto J. Bramer (ETEC) fo/ATV-Vd49'Ql' 8 mI 8506150065 850301 PDR FOIA CARDE84-A-55 PDR
EVALUATION OF UNDERSIZE SCHEDULE 80 SOCKET WELDS ~(SCD 74)
The NRC staff investigated the disposition of NRC 5760 (SCD 74) involving undersize fillet welds on schedule 80 2" and under piping, ASME Section III class 2 and B.
The disposition was found to be satisfactory.
544 fillet welds were initially reinspected by Tomkins Beckwith QA.
Of these, nine were flange welds.
Five of the nine flange welds did not meet the ASME Section III fillet weld size requirements.
Ultimately, all schedule 80 ASME Section III 2" and under flange welds were reinspected and those found undersize were reworked to meet the Section III fillet weld size requirements.
Of the remaining 535 socketed welds reinspected, 54 did not meet the ASME Section III size requirements.
The 54 undersize welds were evaluated using the allowable size requirements established by ASME Code case N 316.
Two of the 54 did not meet the code case requirement.
Based on the low rejection rate upon application of the Code Case requirements, it was deemed unnecessary to reinspect the balance of the schedule 80 fitting socket welds except for the following exceptions:
In order to apply the code case it was necessary to use a more con-servative stress intensification factor in the pipe stress analysis.
l Therefore, it was necessary to establish in which pipe regions the stresses would exceed the ASME Section III allowable stress resulting from the application of the higher code case stress intensification
[
factor.
In those regions where the stress exceeded the allowables l
the code case could not be applied to the fillet weld size requirements, the ASME Section III Code weld requirement must be used.
As a result of l
the analysis an additional 125 schedule 80 socket welds were reinspected.
Three of the 125 reinspected welds did not meet the Section III Code requirement and were subsequently reworked.
l
O
.s 2-4 The -disposition of SCD 74 is considered satisfactory for the following reasons:
1.
All flange welds were inspected and reworked as required to meet the size requirements of the Code.
2.
Less than 0.4% of the remaining welds originally inspected did not meet the size requirements of code case N-316.
3.
The welds in highly-stressed piping regions where code case N-316 could not be applied were reinspected and reworked as required to meet the co'de requirements.
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