ML20054B843

Forwards Listing of Changes,Tests & Experiments Completed During Mar 1982

ML20054B843
Person / Time
Site:	Quad Cities
Issue date:	04/01/1982
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Case E Office of Nuclear Reactor Regulation
References
NJK-82-158, NUDOCS 8204190249
Download: ML20054B843 (4)

Text

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Commonw alth Edison Ould Citi!s Nucliar PowIr Station 22710 206 Avenue North Corcova, lilinois 61242 Telephone 309/654-2241 N

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April 1, 1982 Mr. Edson G. Case, Deputy Director Of fice of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Case:

Enclosed please find a listing of those changes, tests, and experi-ments completed during the month of March 1982, for Quad-Cities Station Units 1 and 2, DPR-29 and DPR-30. A summary of the safety evaluation is being reported in compliance with 10 CFR 50.59.

Thirty-nine copies are provided for your use.

Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION

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2' ij 4 N. J. Kalivianakis (fsWA i

l Station Superintendent bb Enclosu re cc: T. J . Rausch

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5, 8204190249 820401 f PDR ADOCK 05000254 R PDR

r- s M-4-2-80-Il Group i & ll Primary Containnent isolation Description This modification involved the installation of 3 position control switches and associated seal-in relays for Group I and ll Primary Containment isolation valves to ensure that the valves will remain closed when the isolation signal is reset. This has been done to satisfy the requirements of NUREG 0578. The new switches replaced existing 2 position switches, which would allow the valves to automatically re-open when the isolation was reset unless the operator would manually put the switches in the closed position.

Evaluation This modification allows the Primary Containment Isolation valves to remain in their safe position when an isolation signal is reset. This will allow the operator to open only the valves that he deems necessary to have opened, instead of having the valves open automatically to their original position. The probability of a radioactive release to the j envi ronment is reduced as a result of this modification.

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F-M-4-1-81-13 125V DC Main / Reserve Bus Separation Disconnect Switch - Temporary Fix Description As a precautionary measure against fire in the 125V DC Distribution System, this modification is a temporary neans of separating the 125V DC Main and Reserve Bus until the long term solution to bus separation has been imp lemen ted.

This modification was initiated as an immediate temporary solution, as a result of the NRC's Systematic Evaluation Program (SEP). The staff expressed concern that a fire could render the cable providing back-up

feed to the 125V DC Reserve Bus useless, thus, disabling both the Main and Reserve Bus.

To accomplish this temporary solution, installation of manual disconnect switchgear at the Reserve Bus end of the back up feed cable was performed.

Evaluation By providing a manual disconnect switchgear at the Reserve Bus end of the back-up feed cable to the 125V DC Reserve Bus, the possibility of a fire faulting the cable, (thusly, disabling the 125V DC Main and Reserve Bus) is reduced.

The disconnect switchgear does not alter the designed function of the

, back-up feed cable in anyway. The re fo re , it improved the reliability of l the 125V DC Distribution System.

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m M-4-1-81-33 Rewi re Radiation Moni tor Power Supply Description This modification changes the power source for the high range Drywell radiation monitors. These monitors are part of the Containnent Atmospheric Monitoring System. Modification M-4-1-81-4 required the alarm contacts of the high range monitors be wired so as to initiate a Group ll isolation.

Group ll logic required the alarm relays be normally energized and contacts closed. As installed, the monitors and alarm relays were de energized and the alarm contacts open, thereby causing a constant Group ll Isolation. By changing to a continuously energized power source it will eliminate the constant Group 11 isolation. The modification was accomplished by connecting the power lead for high range radiation monitors to the powered side of the Atmospheric Containnent Air Dilution / Containnent Atmospheric Monitor (ACAD/ CAM) control panel (90X-55, 90X-56) power switch.

Evaluation This modi fication does not af fect plant safety in any way. The modification will not affect the designed control logic of the high Drywell radiation Group 11 isolation, or the designed function of the monitors themselves. The modification will permit Group ll high Drywell radiation to function without interferring with ACAD/ CAM's operating procedures.

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