ML18093A660
| ML18093A660 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/31/1986 |
| From: | Corbin McNeil Public Service Enterprise Group |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML18093A661 | List: |
| References | |
| NLR-N86110, NUDOCS 8802250216 | |
| Download: ML18093A660 (3) | |
Text
Public Service Electric and Gas Company Corbin A. McNeil!, Jr.
Vice President -
Public Service Electric and Gas Company P.O. Box236, Han cocks Bridge, NJ 08038 609 339-4800 Nuclear August 31, 1986 NLR-N86110 U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attention:
Dr. Thomas E. Murley, Administrator Off ice of Inspection and Enforcement Gentlemen:
JUSTIFICATION FOR CONTINUED OPERATION FOLLOWING THE SALEM UNIT NO. 2 REACTOR TRIP OF AUGUST 26, 1986 SALEM GENERATING STATION UNITS NO. 1 AND 2 DOCKET NOS. 50-272 AND 50-311
- on August 26, 1986, a reactor trip occurred at Salem Generating Station, Unit No. 2, while technicians were troubleshooting a problem on No. 22 Steam Generator water level control channel III.
In addition to the Reactor Trip, a Safety Injection with Phase A containment isolatio'n occurred.
During the event, all safety equipment functioned as designed, however; subsequent to the block loading of safeguards equipment onto the vital busses, a blackout signal (loss of power to the vital busses) was received at the Safeguards Equipment Controller (SEC).
The presence of the blackout signal resulted in the stripping of all loads from the vital busses, opening of the normal vital bus infeed breakers (i.e. station power transformers), closure of the emergency diesel generator output breakers, and then resequencing of safeguards equipment onto the vital busses.
Although all safety systems performed as expected, the receipt of the blackout signal was unusual in that offsite power was available (i.e., group busses remained energized throughout the event).
Members of your staff were briefed at the site later that afternoon and during the remainder of the week; they conducted a thorough review of the event.
As a result of that review, the sequence of events which led up to the receipt of the blackout signal was identified as a significant area of concern.
8802250216 860831 PDR ADOCK 05000272 p
Dr. Thomas E. Murley 2 -
8/31/86 In response to this concern, a meeting was held in your offices on August 30, 1986.
During that meeting, Public Service Electric and Gas Company (PSE&G) made a presentation which consisted of a reconstruction of the sequence of events leading to the blackout signal, a discussion of the probable causes of those events, and our proposed corrective actions to prevent recurrence.
At the conclusion of the meeting, your staff indicated that our proposed corrective actions were acceptable.
However, prior to returning Salem Unit No. 2 to service PSE&G should submit the following;
- 1) justification for continued operation of Salem Unit No. 1 (which would be deemed equally applicable to Unit No. 2), 2) a description of the administrative controls used to limit plant equipment electrical loads including the appropriate 10CFR50.59 evaluations, and 3) a description of the immediate and long term corrective actions to preclude recurrence. is a Safety Evaluation which provides the detailed bases for justifying continued operation of the Salem Generating Station.
In summary, electrical loads at the Station will be reduced to a level consistent with that in existence during the 1981 time frame.
This reduction would bring the Station back within the design envelope which was verified as part of a Salem specific degraded grid voltage study.
This study was performed by EG&G, Idaho, Inc. on behalf of the NRC and concluded that the electrical distribution design was adequate.
This reduction in load will be accomplished by removing non-essential equipment from service until such time as a detailed reanalysis of the distribution system can be completed.
Station operating procedures will be issued or revised where appropriate to reflect the reduction in available equipment. provides the immediate and long term corrective actions which were discussed during our meeting.
All immediate corrective actions will be completed prior to returning Salem Unit No. 2 to service.
At this time, detailed schedules are not available for our long term corrective actions.
However, we will provide a monthly update to this letter indicating appropriate schedules and status of corrective actions.
If you have any questions in this regard, do not hesitate to contact us.
Sincerely, Attachments
Dr. Thomas E. Murley C
Mr. Donald c. Fischer Licensing Project Manager Mr. Thomas J. Kenny Senior Resident Inspector 3 -
8/31/86