ML20084K622
| ML20084K622 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 06/21/1974 |
| From: | COMMONWEALTH EDISON CO. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084K617 | List: |
| References | |
| AO-50-265-74-11, NUDOCS 8305190498 | |
| Download: ML20084K622 (2) | |
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.0 REPORT hWBER: A0-50-.265/74-11 REPORT DATE: June-21, 1974 OCCURRE?;CE DATE: June 13, 1974 FACILITY: Quad Cities Nuclear Power Station Cordova, Illinois 61242 IDEUTIFIC ATION OF OCCURRENCE:
Condenser Pit Five-Foot Level Switch failed to actuate Control Room Annunciator during monthly testing.
CONDITIONS PRIOR TO OCCURRENCE:
1 Unit 2 Reacter in cold shutdown.
2 All three Unit 2 Circulating Water Pumps operating.
DESCRTW TON OF OCC m W CE:
Level Switch LS-2-4441-24A did not actuate the Control Room Annunciator when monthly surveillance of the Condenser Pit Five-Foot Level Switches was performed in accordance with Technical Specification 4.5.H.1.d.
This switch circuitry was jumpered in the tripped fail-safe condition oer
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Technical Specification 3.5.H.2 A work request was imediately initiated to investigate and repair the apparent malibnetioning trip and alarm cir-cuitry.
DESIGNATION OF APPARE?"P CAUSE OF OCCURRE'!CE:
N.
4 The apparent cause of the failure of the surveillance test of LS-2-4441-24A to actuate the Control Room Annunciator is that the Level Switch Float Plunger was not fully lifted vertically during testing, thus not closing the switch contacts.
ANALYSIS OF OCCURRENCE:
Investigation indicates that no switch failure, and thus no occurrence, actually occurred. Therefore, this incident has no safety implications.
CORRECTIVE ACTIO?!:
Further testing and investigation showed the 1cvel switch trip and alarm circuitrv to ba fully operable. The jumpers on the switch circuitry were t
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removed. Operators will be instructed in the proper method of actuating these level switches for future testing.
FAILURE DATA:
The Five-Foot Condenser Pit Level Switches have performed satisfactorily in previous tests. A similar incident also occurred on June 13, 1974 in testing Unit I Five-Foot Condenser Pit Level Switches (Reference A,0,-
50-254/74-19).
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