ML20057C423
| ML20057C423 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/23/1993 |
| From: | Kennedy J Office of Nuclear Reactor Regulation |
| To: | Farrar D COMMONWEALTH EDISON CO. |
| References | |
| TAC-M87720, TAC-M87721, NUDOCS 9309280353 | |
| Download: ML20057C423 (3) | |
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- UNITED STATES p-
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j NUCLEAR REGULATORY COMMISSION '
2 WASHINGTON, D.C. 20liti6-0001 0
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- s September 23, 1993
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Docket Nos. 50-373 and 50-374 i
r Mr. D. L. Farrar Manager, Nuclear Regulatory Services Commonwealth Edison Company Executive Towers West III, Suite 500 1400 OPUS Place Downers Grove, Illinois 60515
Dear Mr. Farrar:
SUBJECT:
REQUEST FOR APPROVAL OF AN UNREVIEWED SAFETY QUESTION CONCERNING THE MECHANICAL VACUUM PUMP AT LASALLE COUNTY STATIDH, UNITS 1 AND 2' i
(TAC NOS. M87720 AND M87721) i Your letter dated September 10, 1993, submitted documents for our review and 4
approval regarding an unreviewed safety question concerning the ability of the 1
mechanical vacuum pump to trip and isolate upon receiving a " Main Steam Line.
1 High Radiation Signal" for LaSalle County Station, Units 1 and 2.
The purpose of the mechanical vacuum pump trip is to limit the release of fission products.
from the reactor during the design basis control rod drop accident.
l
-NUREG-0519, " Safety Evaluation Report Related to the Operation of LaSalle County Station Units I and 2," indicates that the mechanical-vacuum pump trips 1
on a high main steam line radiation signal. Your letter indicates that the trip of the mechanical vacuum pump was never installed.
Your. letter provided an analysis of fission product releases should the mechanical vacuum pump be running during a control rod drop accident. This analysis concluded that the mechanical vacuum pump is to be tripped within 15 minutes of a main steam line high radiation signal to ensure dose limits are maintained within the Standard Review Plan, Section 15.4.9, acceptance criteria.
Your letter also provided.
compensatory-measures being taken to address the function of the mechanical vacuum pump if a main steam line high radiation signal were received.
Shortly after receipt of your request, LaSalle County Station, Unit 1, was I
forced to shut down after losing offsite power.
It is-the staff's understanding that a loss of offsite~ power causes a loss of the mechanical vacuum pump; therefore, there was no safety concern during shutdown. The mechanical vacuum pump is used primarily during startup prior to placing the steam jet air ejectors in service. Therefore, in order to restart Unit 1 from the forced shutdown, approval from the:NRC regarding the mechanical vacuum i
pump unreviewed safety question is needed.
~
Based 'on a preliminary review of your submittal, the staff has determined that
.LaSalle County Station, Unit 1, can be safely returned to operation with the operator actions and administrative controls you have put in place.
Specifically, LaSalle abnormal procedures (LOA-NB-08, LOA 1(2)H13-P603-B305, j
-l and LOA 1(2)H13-P603-8309) have been revised to require remote manual trip of j$booh OS f
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Mr. D. L. Farrar September 23, 1993 the condenser mechanical vacuum pump as an immediate operator action, based on the determination that the mechanical vacuum pun. was assumed to automatically trip..Information concerning the need to complete this a. tion within 15 minutes to remain within the analysis limits for off-site dose is provided in the procedures. Our detailed safety evaluation will be provided under separate cover.
If you have any further questions, please call me st (301) 504-1333.
Sincerely, Original signed by:
Janet L. Kennedy, Project Manager Project Directorate III-2 Division of Reactor Projects - III/IV/V Office of Nuclear Reactor Regulation cc:
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-4 Mr. D. L. Farrar LaSalle County Station Commonwealth Edison Company Unit Nos. I and 2 cc:
Phillip P. Steptoe, Esquire Robert Cushing Sidley and Austin Chief, Public Utilities Division One First National Plaza Illinois Attorney General's Office Chicago, Illinois 60603 100 West Randolph Street Chicago, Illinois 60601 Assistant Attorney General 100 West Randolph Street Michael I. Miller,-Esquire Suite 12 Sidley and Austin Chicago, Illinois 60601 One First National Plaza Chicago, Illinois 60690 Resident Inspector /LaSalle, NPS U. S. Nuclear Regulatory Commission Pr. G. Diederich Rural Route No.1 LaSalle Station Manager P. O. Box 224 LaSalle County Station Marseilles, Illinois 61341 Rural Route 1 P. O. Box 220 Chairman Marseilles, Illinois 61341 LaSalle County Board of Supervisors LaSalle County Courthouse Ottawa, Illinois 61350 Attorney General 500 South 2nd Street Springfield, Illinois 62701 Chairman Illinois Commerce Commission Leland Building 527 East Capitol Avenue Springfield, Illinois 62706 Illinois Department of Nuclear Safety Office of Nuclear Facility Safety 1035 Outer Park Drive r
Springfield, Illinois 62704 Regional Administrator, Region III U. S. Nuclear Regulatory Commission J
799 Roosevelt Road, Bldg. #4 i
Glen Ellyn, Illinois 60137 Robert Neuman Office of Public Counsel State of Illinois Center 100 W. Randolph Suite 11-300 Chicago, Illinois 60601 l