ML18078A925
| ML18078A925 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 01/26/1979 |
| From: | Schneider F Public Service Enterprise Group |
| To: | Brunner E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML18078A924 | List: |
| References | |
| NUDOCS 7903070489 | |
| Download: ML18078A925 (2) | |
Text
Frederick W. Schneider Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 201/430-7373 Vice President reduction January 26,.1979 Mr. Eldon J. Brunner, Chief Reactor Operations and Nuclear Support Branch U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Dear Mr. Brunner:
NRC INSPECTION REPORT NO. 50-272/78-26 SALEM GENERATING STATION UNIT NO. 1 Your *letter of December 13, 1978, which transmitted Inspection No. 50-272/78-26, identified your concern in certain areas that this response will address.
1~aJaphrasing your first item of concern, you have asked us to supply a*response describing in detail the actions we have taken to ensure the inadequacy found in our procedure for containment venting does not exist in other procedures.
The inadequacy of the containment ventilation procedure was due to the fact, that, in order to initiate a containment pressure relief, vacuum relief or purge when the containment process radiation monitors were above their alarm point, resetting of the containment ventilation isolation signal was permitted when a grab sample of the containment air indicated the monitor reading to be in question.
What was not realized when this procedure was prepared was that resetting the con-tainment ventilation isolation signal, due to the containment process radiation monitors above their alarm value, also blocked the safeguards isolation signal which would prevent containment ventilation isolation in the event of a safety injection/phase A isolation signal.
During the preparation of this procedure, the Salem staff used the proper material for its preparation which included the engineering system description and information supplied by the vendor.
The deficiency originated with the vendor de~ign of the system logic permitting the block to occur.
A design change (DCR l-EC-430r has been installed to insure a safeguards safety injection/phase A isolation signal will close the containment ventilation valves if they are open for any ason.
In addition, the revised containment ventilation procedure not permit normal containment pressure relief,. vacuum relief or
_ge with any of the containment process radiation monitors in alarm.
To insure that no similar protection or safeguards system logic errors exist, our Engineering Department performed a review of the Safeguards Equipment Control System and the Solid State Protectio~ System.
The
\\
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U. 1/26/79 results of this review which will be available at the Salem station for inspection, verify that no similar deficiencies in the system logic exist.
From an operational viewpoint, we are confident that no other unwanted signal blocks exist when safeguards reset functions are used.
During the normal course of plant operation and surveillance testing, each reset has been functionally tested and the system logic has been found to operate properly.
We feel a high degree of assurance that there are no other system inadequacies and that no inadequacies of this type exist in other procedures.
The response to your second concern which identifies the conflict between the design of our Solid State Protection System and IEEE 279-1971, is directly related to the apparent procedural deficiency noted above.
The design of the Solid State Protection System did not prevent the sequence of events as they occurred at Salem.
Given a valid process radiation monitor signal above the alarm point, the design intent is to close the containment ventilation valve and containment.
When
/-the radiation signal was verified to be in question, a reset was per-m~tted which resulted in the bypassed safety injection/containment v~ntilation isolation logic.
As stated previously, a design change has been incorporated to correct this deficiency.
The engineering review results and operational experience confirm that no other in-adequacies in this area exist.
The current design complies with the requirements of IEEE 279-1971.
We are confident this response satisfies your concerns.
If you should have any further questions, please feel free to contact us.
Sincerely, CC:
Director -
Inspection and Enforcement USNRC Washington, D.C.
20555