ML19208B870
| ML19208B870 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/31/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19208B865 | List: |
| References | |
| NUDOCS 7909210517 | |
| Download: ML19208B870 (3) | |
Text
.
SAFETY EVALUATION REPORT DAVIS-BESSE 1 ALTERNATIVE TO KEYLOCK CONTROL TO BYPASS VALVES TAC 10999 AUGUST 1979 Prepared By:
Plant Systems Branch Division of Operating Reactors 25 ]
990 5 7900210 5774
1.0 INTRODUCTION
By letter dated January ll, 1979, Toledo Edison transmitted the technical report " Reliability Study of Davis Besse 1 Decay Heat Removal System Suction Bypass" in response to NRC SER NUREG-0136, Supplement No.1, dated April 1977.
The SER license condition required the licensee to submit an analysis of design modification alternatives for the present keylock control in the manual bypass valves DH21 and DH23 around the DHR suction line valves to decrease the likelihood of the bypass path being opened inadvertently when isolation of the DHR loop is required.
2.0 EVALUATION The enclosed Technical Evaluation Report was prepared for us by the Lawrence Livermore Laboratory as part of our D0R technical assistance program.
3.0 CONCLUSION
S Based on the review of our consultant's enclosed Technical Evaluation Report, we agree with their conclusions that:
(1) the licensee's analysis of design modification alternatives for the present keylock control of the manual bypass valves DH21 and DH23 satisfies our SER Supplement No.1 license condition; and (2) the proposed procedural change entailing the use of one unique key and lock to secure bypass valves decreases the likelihood of the bypass being opened inadvertently when isolation of the DHR loop is required.
The proposed analysis of design modification alternatives is, therefore, acceptable to us.
2T9 S30 8a