ML20154C557
| ML20154C557 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/09/1988 |
| From: | Miller H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML20154C561 | List: |
| References | |
| NUDOCS 8809140409 | |
| Download: ML20154C557 (2) | |
See also: IR 05000373/1988016
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Docket No. 50-373
Docket No. 50-374
Commonwealth Edison Company
ATTN:
Mr. Cordell Reed
Senior Vice President
Post Office Box 767
Chicago, IL 60690
Gentlemen:
This letter forwards the results and conclusions of the PRA inspection of
the LaSalle County Station conducted between June 27 and July 22, 1988.
The
purpose of this inspection was to assess the adequacy of activities affecting
items identified by the LaSalle Unit 2, Prcbabilistic Risk Assessment (PRA)
as contributing most to plant risk.
While this PRA is not complete, no
significant change in the dominant contributors to plant risk is anticipated.
Two violations were identified during this inspection as described in the
enclosed Notice.
A written response is required.
One of these was of special
concern since it involved the failure to take prompt action to correct a
potential common mode failure of the station emergency diesel generator output
breaker closing circuits.
The station had been informed in 1984 by your
Station Nuclear Engineering Department of industry problems with certain
relays used in the closing circuits of emergency diesel generators at LaSalle..
The station failed to take any corrective action until three failures of these
relays occurred at LaSalle in 1987.
Corrective action is still not complete.
We request that you take prompt action in determining if the station staff is
adequately trained to recognize and respond to significant safety issues.
Your response should describe those actions you plan to take to ensure that
significant safety issues are promptly addressed and corrective action completed
within a responsible period of time.
Another safety concern identified during the inspection was the unreliability
of the air compressors at the station.
Specifically, the instrument air,
drywell pneumatic, and diesel generator air start system compressors all
exhibited poor reliability.
This concern was underscored subsequent to the
inspection by problems with the Unit 2 drywell pneumatic system on August 31,
1988 leading to a plant shutdown.
All of these systems are identified by the
PRA as dominant contributors to plant risk.
Your response should address your
plans for increasing the reliability of these systems.
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Commonwealth Edison Company
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In accordance with 10 CFR 2.790 of the Commission's regulations, a copy
of this letter, the enclosures, and your response to this letter will be
placed in the NRC Public Document Room.
The responses directed by this letter and the accompanying Notice are not
subject to the clearance procedures of the Office of Management and Budget
as required by the Paperwork Reduction Act of 1980, PL 96-511.
We will gladly discuss any questions you have concerning this inspection.
Sincerely,
DihGl% SiGNEQ B.( fitJslar J. I,IlLLER
Hubert J. Miller, Director
Division of Reactor Safety
Enclosures:
1.
2.
Inspection Reports
No. 50-373/88016(DRS);
No. 50-374/88015(ORS)
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cc w/ enclosures:
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H. Bliss, Nuclear
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Licensing Manager
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G. J. Diederich, Station
Manager
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Licensing Fee Management Branch
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Resident Inspector, RIII
Richard Hubbard
J. W. McCaffrey, Chief, Public
Utilities Division
David Rosenblatt, Governor's
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Office of Consumer Services
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