ML20024B285
| ML20024B285 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 06/24/1983 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20024B283 | List: |
| References | |
| NUDOCS 8307080250 | |
| Download: ML20024B285 (1) | |
Text
. s.
ENCLOSURE
~,
SUPPLEMENTAL SAFETY EVALUATION RANCO SECO STATION OVERRIDE OF CONTAINMENT PURGE ISOLATION -
CONTROL ROOM RADI ATION MONITOR AND CONTAINMENT VENTILATION ISOLATION MANUAL SWITCHES Introduction On August 2,1982, a Safety Evaluation was issued (Reference 1) regarding the override of containment purge isolation for Rancho Seco.
The Safety Evaluation found the electrical aspe c s of the override of containment purge valve isolation to be acceptable.
Incidental to the Safety Evaluation, the memo transmitting the evaluation identified that the radiation monitors used to automatically isolate the control room should be upgraded to safety grade, and that a manual system-level isolation switch be incorpor-ated into the containment ventilation isolation system circuit.
Eval ua tion On November I6,1982, the licensee responded (Reference 2) to the incidental l
concerns identified in the electrical cyerride review.
The licensee stated that they are in the process of upgrading the radiation monitor used for initiation of control room isolation to safety grade.
The upgrading of the radiation monitor to safety gr.ade satisfies our: concern for control
~'-
room isolation.
Regarding the containment ventilation isolation system circuit, the licensee stated that there is a separate switch for each valve for manual operation.
Considering that there are only two pairs of valves of concern, we conclude that the intent of manual system-level isolation of the containment ventilation system has been satisfied in the design.
Conclusion Based on our review, we conclude that the upgrading of the control room radiation monitor to safety grade and the provisions of the design for manual isolation of containment ventilation satisfied our previous concerns and are therefore acceptable.
This Safety Evaluation was prepared by T. Alexion and J. Calvo, Operating Reactors Assessment Branch.
Re ferences 1.
Memorandum from Thomas A. Ippolito to Gus C. Lainas dated August 2, 1982,
SUBJECT:
Rancho Seco Station - Override of Containment Purge Isolation 2.
Letter from Kenneth J. Mellor to the Director of Nuclear Reactor Regulation dated November 16, 1982,
SUBJECT:
Rancho Seco Unit 1 -
Generic Item 8-24 and NUREG Item II.E.4.2.
8307000250j3gg2 PDR ADOCK PDR P
._