ML20153B197
| ML20153B197 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/11/1988 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20127A683 | List:
|
| References | |
| NUDOCS 8803210469 | |
| Download: ML20153B197 (2) | |
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UNITED STATES
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- NUCLEAR REGULATORY COMMISSION i
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- j WASHINGTON, D, C. 20655 SE000YAH NUCLEAR POWER PLANT UNITS l'& 2 i
SAFE ~fY EVALUATION REPORT FOR EMPLOYEE CONCERNS ELEMENT REPORT 218.7(B), REVISION 2 "PIPE STRESS CALCULATIONS ACCEPTANCE CRITERIA l
FOR OVERLAP AREAS OF CALCULATIONS" I.
Subject Category:
Engineering (20000)
Subcategory:
Pipe Stress Calculations (21800)
Element:
Acceptance Criteria for Overlap Areas of Calcelations (71807)
Concern:
IN-85-039-003 The basis for Element Report ?18.7(B), Revision 2 is Employee Concern IN-85-039-003 which ccestions the consistency of the use of piping analysis overlap modeling techniques used for alternately analyzed piping at Watts Barr.
II.
Sumary of issues The Employee Concerns Task Group (ECTG) report identified the following two issues from the employee concern:
a.
There was no consistent policy on what constituted an acceptable lapped region at alternate analysis boundaries.
l-b.
The trethods actually inplemented interfacing alternate analysis problems may not have teen sufficient.
III. Evaluation 1
A technical review of Employee Concerns Element Report 218.7(B), Revision 2 was perfomed by NCT Engineering, Inc. under NRC Contract No. 05-86-156.
The results of this review are sumarized in the attached NCT technical evaluation j
report dated Hovember 30, 1987 cn Employee Cancerns Element Report 218.7(B),
Revision 2.
- 1 Element Report 218.7(B), Revision 2 found that the employee concern was valid for the issue of TVA's implementation of overlap criteria at Secuoyah.
TVA a
proposed corrective actions to address the finding in the ECTG report. The implementation of TVA"s corrective actions, as modified to address ECTG 1
comn.ents, was found to be acceptable in an ECTG closecut verification rcemorandum dated July 30, 1987. The NCT review of Element Report ?l8.7(B),
Revision 2 and T'JA's corrective actions found that TVA's review of the issues were acceptable. The staff concurs with the conclusions presented in the NCT technicas evaluation report.
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~. The NCT technical evaluation report identified one open issue.
TVA's evaluation of Nonconformance Report No. SONCEB8303 identified 16 rigorous /
alternate boundaries that were found to be unacceptable and requireo further review. TVA's proposed resolution of these 16 interface problems is to address these problems in the post restart portion of the alternate analysis program.
The alternate analysis program has been previously audited by the NRC and a separate NRC safety evaluation report cn the Sequoyah Nuclear Performance Plan has addressed the technical issues that were determined to be prerestart items.
The issues addressed in the prerestart portion of the alternate analysis program were based on an evaluation of siternate analysis piping deficiencies and the identification of those deficiencies which could adversely affect the piping system integrity. The prerestart evaluation included a review of rigorcus/ alternate boundaries for the effects of anchor movements. This review provided adequate assurance of the acceptability of rigorous / alternate interfaces for the prerestart program.
The post restart portion of the alternate analysis program will review all alternately analyzed piping for conformance to the design criteria. Therefore, TVA's resolution of the 16 interface problems identified by SONCEB8303 in the post restart portion of the alternate analysis program is considered acceptable to the staff.
IV.
Conclusions Based on the review of Employee Concerns Element Report 218.7(B), Revision 2 and TVA's corrective actions, the staff concludes that Etployee Concern IN-85-039-003 has been adecuately addressed.
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