ML19347C828
| ML19347C828 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 08/31/1973 |
| From: | Ross D JERSEY CENTRAL POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 8103041000 | |
| Download: ML19347C828 (3) | |
Text
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Jersey Central P,og($,! & Lightbompany
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M ADisoN AVENUE AT PUNCH BOWL Ro AD e MoRRISToWN, N.J. 07960 e 539-6111 August 31, 1973 Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region I United States Atomic Energy Commission 970 Broad Street Newark, New Jersey 07102
Dear Mr. O'Reilly:
Subject:
Oyster Creek Station Docket No. 50-219 Fish Mortalities This letter is in response to a request received from your office for an information report regarding the August fish mortalities which occurred at Oyster Creek.
On the afternoon of August 9,1973, while the Oyster Creek Nuclear Generating Station was operating at full load, a fish mortality occurred.
(See
" Chronology of Oyster Creek Fish Mortalities Events", attached.)
Based on estimates of the fish that were seen on the surface of the Oyster Creek discharge canal, approximately 2,000 to 4,000 were killed. The cause of death is attributed to increased water temperatures resulting from'the automatic shutdown of one of the plant's dilution pumps. These pumps take water from the bay via the intake canal and dilute the warm water exiting from the plant to reduce its temperature in the Oyster Creek discharge canal.
A Jersey Central Power G Light Company consulting biologist examined specimens of the dead fish and attributes their death to thermal shock resulting from the water temperature rise following the trip-off of the dilution pump.
Although a second dilution pump was started within 30 minutes, it was not in time to prevent the fish mortality.
Company repr.esentatives notified appropriate state and federal agencies after the mortalities occurred. They continue to cooperate fully with State of New Jersey Fisheries' personnel who are investigating this event.
This is the first time since the plant went into operation in 1969 that a fish mortality has ever occurred during the summer months.
Once in 1972 (January 29) and twice in 1973 (January 8 and February 16), fish mortalities were experienced, but only during the winter months as noted.
It is not an unusual situation to shut down the dilution pumps during the summer months (June to August inclusive). An examination of plant records indicates that on at Icast five occasions, the plant operated during the summer months without dilution flow.
f/03odooo
t Mr. O'Reilly August 31, 1973 i
Water samples collected during this event have been analyzed. There was no detectable activity present above background, and chemical content of the water was typical for water in the area. The fish were analyzed for the presence 40g, 60 o, 134 s, 137Cs.
of radioactivity and found to contain normal IcVels of C
C Thus, it can be concluded chemical impurities and/or radioactivity in no way were associated with the observed fish mortality.
In an effort to minimize the probability of a recurrence of this event, station operators have been advised to start another dilution pump immediately upon acknowledging a trip of the operating unit during the summer period. This will normally result in reestablishing dilution flow within 5 to 10 minutes.
Ve truly yours, W
r Donald A. Ross Manager, Nuclear Generating Stations DAR:cs Attachment O
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w CHRONOLOGY OF OYSTER CREEK FISif MORTALITIES EVENTS AUGUST 9, 1973 Oyster Creek Nuc1 car Generating Station was operating at full load (630 MNe gross) during the entire time period spanned by this occurrence.
1400 Hours Condenser inlet temperature - 80* F.
Condenser outlet temperature - 102* F.
Route #9 bridge over discharge canal - 92* F.
1415 Hours No. I dilution pump tripped off automatically due to low water level switch actuation.
The dilution trouble alarm was received in the control room.
Plant operators went out to the dilution pump structure to investigate the cause 'of the alarm.
An attempt was made to restart No. I pump, but was unsuccessful.
1444 Hours No. 3 dilution pump was started.-
1450 Hours Bridge temperatures starting to increase.
1455 liours Plant instrument technician was working on an environs monitor at the Oyster Creek bridge when he noticed fish floating down towards him in the di.scharge canal. He immediately notified the appropriate members of the plant staff.
1500 llours Samples of dead fish and Oyster Creek discharge canal water to collected for future examination and analysis.
1530 liours 1525 Ilours Bridge temperature reaches maximum at 99* F. and begins to decrease.
Approx.
Bridge temperature returns to original level of 92* F.
1540 llours 1530 llours Notification of appropriate company, state, and federal personnel, to 1700 liours O
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