ML20084S506
| ML20084S506 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 09/29/1971 |
| From: | Haueter R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084S508 | List: |
| References | |
| NUDOCS 8306170073 | |
| Download: ML20084S506 (2) | |
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Dr. Peter A. Morris, Director Re: Docket No 50-255
% D b<' d Division of Reactor Licensing License No DPR-20 US Atomic Energy Commission Palisades Plant
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Washington, DC 20545
Dear Dr. Morris:
This letter vill confirm our recent discussion with the USAEC Compliance Office, Chicago, and provide supplemental informa-tion for our letter dated September 9, 1971 concerning the incident involving the emergency power supply at Palisades.
An investigation of the incident revealed that all four 345 kV lines into the substation were energized at the time of the incident and that lightning faulted the 345 kV Argenta No 2 Line.
The Argenta end of the line and one breaker at Palisades cleared properly. The 2TR8 air blast breaker at Palisades failed to trip by primary relaying and after a few cycles the breaker failure relays operated to clear the 27R8 breaker and "R" bus. Relaying for these conditions was correct. This is contrary to our earlier information as reported in our September 9, 1971 letter.
The 27R8 air blast breaker circuitry was tested and the breakers repeatedly tripped in an effort to again initiate the malfunction. This malfunction could not be repeated. If further testing proves futile, certain components of the primary relays on this circuit will be replaced as a precautionary measure to i
possibly prevent a future occurrence of the above.
A viring error was found to have caused the failure of the number 1-2 diesel generator to automatically close in on the dead 2h00 volt 1D bus after power was lost from the startup trans-former. Contrary to the electrical drawings, the permissive con-tacts to breaker number 152-213 (diesel generator) were wired to l
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Dr. peter A. Morris 2
US Atomic Energy Commission September 29, 1971
" movable" type contacts rather than stationary contacts in breaker cell number 152-203(stationpowerto1Dbus). Thus, continuity was broken to the diesel start circuitry with breaker number 152-203 in the " racked out" position.
- Breaker number 152-203 (station power to 1D bus) was placed in the test position and caution tegged thus, placing the
" movable" contacto into the circuit that will allow the diesel generator to close into the 1D bus normally.
The wiring error will be corrected before power operation.
Yours very truly, k L Huw;,
ERC/mho Robert L. Haueter Electric Production Superintendent - Nuclear CC: BHGrier USAEC Compliance, 000
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At the time of this incident no power was.being fed from the main transformer bank via the station power transformers because of plant status and the low power demand for station auxiliaries.