ML18089A317
| ML18089A317 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/18/1983 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML18089A316 | List: |
| References | |
| IEB-80-11, NUDOCS 8308260196 | |
| Download: ML18089A317 (3) | |
Text
ENCLOSURE SAFETY EVALUATION REPORT MASONRY WALL DESIGN, IE BULLETIN 80-11 SALEM GENERATING STATIONS UNITS 1 AND 2 DOCKET NOS.:
50-272/311 The findings reported in this Safety Evaluation report (SER) are based
- on the attached Technical Evaluation Report (TER) prepared by Franklin Research Center (FRC) as a contractor to NRC.
This* TER contains the details of construction techniques used,*technical infonnation reviewed, acceptance criteria, and technica.1 findings with respect to_masonry wall construction at S'alem un.its.
The staff has reviewed this TER and concurs with its.technical findings. The following is our summary of major technical findings.
(1)
As indicated in the Section 3.1 of the TER, the licensee's criteria used in the re-evaluation of the masonry walls at Salem, in general, comply with the staff's acceptance criteria. The only differenc2.between the staffs acceptance criteria and the licensee's criteria is the higher allowable. stresses permitted in the licensee's criteria for the load combinations involving design basis earthquake loads.
However, the examination of actually calcuiated stresses in the walls indicates that, only three'Wal.ls (Wall No. 9 in Unit 1, Wall No. 2 - 9 in Unit 2 and Wall No. 14 in walkway and truck bay area) exceed the allowable stresses permitted by the staff's acceptance criteria. For walls No. 9 and 2 - 9, the exceedances are in order of 8%.
These exceedances in stresses are juC:ged to be nominal and are compensated by the conservatisms used in the analysis (as noted in the TER).- These walls are, therefore, shown to have*met the intent ~f the staff's criteria. With regard to the wall No. 14, whose calculated stresses exceed the staff's allowable by 18.5%, the licensee has proposed to instali a wire mesh structure to protect the safety related equipment in the vicinity of this wall from a postulated failure of the lower section of the wall in order to qualify the wall.
The upper portion of the wall is structurally separate from the lower portion and is shown to have met the staff's acceptance criteria. The licensee's approach is considered adequate and acceptable.
The staff concludes that all the differences between the staff's acceptance criteria ~nd the licensee's reevaluation criteria are*
considered resolved.
(2)
The Section 3.2 of the TER summarizes the licensee's approach to wall modifications. Modifications which were planned to be completed by January, 1981 were completed and verified by inspectiort (Ref. 1). The wire mesh structure, as described above~
is also now installed.
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- (3)
The license condition No. 2.C (23)(b) for Salem 2 requires that prior to startup following the first refueling, the licensee shall resolve the differences between the staff criteria and the criteria used by the licensee* to the satisfaction of the NRC staff and implement the required 'fixes that might result: from such a resolution. The issues* of differences in criteria and required fixes are discussed in (1) and (2) above.
Based on findings in I~ems (1), (2), and (3) above, the staff concludes that there is reasonable assurance that, in the event of wind, tornadoes; earthquakes, and various postulated accidents occurring within
- Category I Structures, the safety-related masonry walls at Salem Units will *withstand the specified design load conditions without impairment of (a) wall integrity or (b) the performance of required safety functions. The staff further concludes that Items 2 and 3 of IE Bulletin 80-11 have been fully implemented at Salem Units and the differences between the licensee's criteria and the staff's acceptance criteria have been fully resolved as required by the license condition No. 2.C (23)(b) for Salem 2.
Region I staff will verify the implementation of the resulting fixes as required by the license condition.
Reference
- 1)
Letter to Public Service Electric and Gas Company from R. R. Keimig*
of NRC,
Subject:
Combined Inspection 50-272/81-04 and 50-311/81-05, dated March 30, 1981. *
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ATTACHMENT TO ENCLOSURE,
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