ML20090D429
| ML20090D429 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point, Oyster Creek, 05000000 |
| Issue date: | 10/06/1972 |
| From: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20090D412 | List: |
| References | |
| 5508, NUDOCS 8302280157 | |
| Download: ML20090D429 (2) | |
Text
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M ADISON AVENUE AT PUNCH BOWL RO AD e MORRisTOWN. N.J. 07960 e 539 6111 October 6, 1972 61 D
e Mr. A. Giambusso m-u
- f Deputy Director for Reactor Projects J.
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Directorate of Licensing b
OCT101972> I, United States Atomic Energy Co =nission Washington, D. C. 20545 g
us. $NEW C
Regulatory
Dear Mr. Giambusso:
"*U M g
Subject:
Oyster Creek Station Docket No. 50-219 Inoperable Standby Liquid Control System the purpose of this letter is to report to you an incident that occurred at Oyster Creek on September 26, 1972 in which it was discovered that the two pumps in the standby liquid control system were inoperable at the same time.
At 10:45 a.m. on September 25, 1972, the "A" standby liquid control pump was removed from service for replacement of the pump packing. The pump was taken out of service using Technict.1 Specification 3.2.C.3 as the basis.
It states, "If one standby liquid control system pumping circuit becomes in-operab1c during the run mode and specifiedtion 3.2.A is met, the reactor may remain in operation for a period not to exceed neven dayn, provided the pump in the other circuit is demon-otrated daily to be operable". Specification 3.2.A is met, therefore, the "A" pump breaker was racked out and the pump necured in accordance with plant safety procedures. The work was not completed by the end of the day shif t, and the "A" pump was inf t in an inoperable condition. At 4:20 a.m. on September 26, 1972, the "B" liquid control system pump was to be run to comply with Technical Specification 3.2.C.3.
When the operator depressed the start button, the pump did not start.
An interlock in the starting circuitry prevents two standby liquid control pumps f rom being run simultaneously.
This interlock also prevents the "B" pump from starting when the "A" pump breaker is in the racked out position. The interlock is compoced of a normally closed contact in the starting circuit of each pump. This contact is operated from a relay in the opposite pump circuit.
If the "A" standby liquid control pump is started either from the 5508 control room with the key lock switch or locally f rom the 8302280157 730425 PDR ADOCK 05000220 O
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Mr. A. Giambusso Page 11 l
October 6, 1972 push button station, a relay is picked up which opens the normally closed contact in the "B" standby lic,uid control pump starting circuit which provents this pump from operating with the "A" pump running. The reverse is true if thn "B" pump in started. The problem developed when the breaker for the "A" pump was racked out.
It dionbled the pump and at the same time it physienlly removed the contact in the starting circuitry for the "B" pump which aimulated an open contact. This prevented the "B" pump from ntarting.
As soon as the Shif t Foreman was aware of the inoperability l
of both pumps, he started a normal shutdown of the plant. In the meantime, he received permission to clear the maintenance safety togo and rack the "A" pump breaker to its normal position. lie then ran a successful operability check on the "B" pump.
"he load reduction was stopped and the plant returned to full load.
In order to prevent a recurrence of this event, operating procedures have been changed so that operability tests of redundant eng1neered sofcguards system components will be made immediately following any action that requires one of the systems to be inoperable for maintenance purposes.
' We are encloadng forty copies of this letter.
Very truly yours, h(j11 h,
, i M N
Ivan R. Finfr ek, Vice Presiden IRF/pk
$nclosures cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region 1