ML20153B204
| ML20153B204 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/11/1988 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20127A683 | List:
|
| References | |
| NUDOCS 8803210476 | |
| Download: ML20153B204 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION
- p WASHING TON, D. C. 20555
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,o SAFETY EVALUATION PEPORT BY THE OFFICE OF SPECIAL PR'0JECTS
_ EMPLOYEE CONCERN ELEMENT REPORT 220.1(B)
"A SERIES DRAWINGS AND 050 NOTES" TENNESSEE VALLEY AUTHORITY, SEQUOYAH NUCLEAR POWER PLANT, UNITS 1 AND 2 COCKETNOS.50-327JND50-328 SUBJECT Category:
Engineering (20000)
Subcategory:
Support Design General (22000)
Element:
"A" Series Orawings and "050" Notes (22001)
The basis for Element Report 220.1(B) Revision 1, dated January 8, 1987 is Employee Concern IN-85-024-001 which states:
"A series hanger orawings and 050 notes are contradictory and allow hangers or box anchors or structural features to be acceptable, even when they do not conform to the requirements of drawing details.
The 050 series notes are misinterpreted by all those who utilize them."
This concern was evalucted by the licensee as poter,tially nuclear safety-related and potentially applicable to Sequoyah (generic).
4 II.
SUMMARY
OF ISSUES Three issues were defined by the licensee as applicable to this evaluation:
1.
47A050 notes are contradictory to "A" series hanger drawings.
They allow hangers, box anchors, and structural shapes to be accepted even though they do not conform to the desten requirements.
2.
47A050 notes are written in such a way that they can be misinterpreted.
3.
There are discrepancies between 47A050 notes and other installatien documents.
III. EVALUATION The licensee's evaluation team reviewed the employee concern in the latter part of 1986 and concluded that there were not any conflicts between the "A" series hanger drawings and the 47A050 notes.
The notes were found.to be concise, clear ano easy to interpret.
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-2 However, the Nuclear Safety Review Staff report (!-85-110-WBN-01) on the same concern in 1985 resulted in numerous findings.
There were 74 pages of drawing notes and the Office of Engineering personnel were making about five changes per week.
Several contradictory notes were fcund and the conclusion was that the notes caused considerable confusion ano n.ultiple interpretations.
In addition, Finding QP.3-1 of the Institute of Nuclear Power Operations evalua-tion of Watts Bar construction specifically mentioned the 47A050 notes as being a contributing factor in the high rejecticn rate.
Since both Sequoyah and Watts Bar drawing notes were written by the same engineering office at about the same time, the employee concern is substantiated.
Since the INP0 findino and other Employee concerns such as those found in Element Reports 215.9(B) and 222.5(B), the licensee perfomed a general review and improvement of the drawing notes.
Most of these revisions took place in the first half of 1986.
The NRC staff reviewed the present drawing notes for Sequoyah anc found the notes to be clear and ncn-contradictory.
Several notes contain engineering decisions that should be discussed in the future, but these notes are also clear and understancable.
The staff also reviewed senral Watts Bar drawings.
It is not known if these drawings have been updated.
47A050-1N Revision 9, dated September 10, 1985, " Wismic Category I Structures, Mechanical Hanger Drawing Notes" Note 51 "Where the weld spr.bol for a specific weld is not applicable to the actual configuration, the appropriate type of weld of the same size is authorized."
47A050-1N Revision 9, dated September 18 Ica, "Seismic Category I Structures, Mechanical Hanger Orawing Notes' hote 81 "Lugs shown fastened to oipe by flare bevel welds shall be attached with full penetration welds en all category supports."
47A050-1N2 Revision A dated harch 31, 1986 "Seismic Category I Struc-turcs, Mechanical Hanger Drawing General Notes" Note 130 "When improper welds are specified..."
Note 51 essentially requires the inspector to look at the weld and make en engineering judgment as to the type of weld required.
Note 81 is not physical-ly cossible in all configurations.
Note 130 also requires an engineering judgment.
These type of notes were not found on Sequoyah drawings.
IV. CONCLUSION The Element Report did not thoroughly evaluate the employee ccncern.
The NPC l
staff reviewed the concern and the corrective action for the Sequoyah Nuclear j
Plant is acceptable.
The employee concern is substantiated.
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