05000312/LER-1982-013, Forwards LER 82-013/04T-0.Detailed Event Analysis Submitted

Forwards LER 82-013/04T-0.Detailed Event Analysis Submitted

ML20054L784
Person / Time
Site:	Rancho Seco
Issue date:	06/14/1982
From:	Walbridge W SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20054L785	List: 05000312/LER-1982-013, Forwards LER 82-013/04T-0.Detailed Event Analysis Submitted 05000312/LER-1982-013-04, /04T-0:on 820607,during Chlorination of Nuclear Svc Spray Pond,Spray Pond Filters Went Into Backwash Mode. Cause Not Stated.Several Fish in Discharge Stream Killed Due to Excessive Chlorine.Chlorine Injection Point to Be Mov
References
NUDOCS 8207080477
Download: ML20054L784 (2)

LER-1982-013, Forwards LER 82-013/04T-0.Detailed Event Analysis Submitted

Event date:
Report date:
3121982013R00 - NRC Website

text

i+$ SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830. Sacramento, California 95813, (91',) 452d211 June 14, 1982 1

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it R H ENCELKEN, REGI0flAL ADMINISTRATOR 5

REGION V 0FFICE OF INSPECTION AfJD EflFORCEPEriT U S NUCLEAR REGULATORY COMMISSION

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1450 MARIA LANE SUITE 210 WALNUT CREEK CA 94596 1

DOCKET NO. 50-312 LICENSE NO. DPR-54 LICENSEE EVENT REPORT 82-13 In accordance with Rancho Seco Nuclear Generating Station Technical Specifications Appendix B, Section 5.6.2.C the Sacramento Municipal Utility District is hereby submitting the following 10-day report on Licensee Event Report Number 82-13.

At 0130, on June 7,1982, plant operators began chlorine addition to the east Nuclear Service Spray Pond via the Hypochlorite Chemical Tank Metering Pump P-471B, into the suction of the Nuclear Service Paw Water Circulating Pump, P-476B.

At approximately 0205, high pH alarms were received from the inlet pH alarm at the plant discharce. At approxi-mately 0230, the plant operator manually diverted plant discharge to the retention basins. Subsequently, the operatcr noticed a strong chlorine odor from the basins.

The operator secured the hypochlorite metering pumps, and found the spray pond filter, F-475B, operating in a backwash mode, which flows to the plant discharge.

Since the filters are in line with the circulating pump, this resulted in the concentrated chlorine going to the plant discharge.

Chemistry analysis of the flow into the retention basin following diver-l sion indicated 110 ppm chlorine. A sample taken at the site boundary l

indicated approximately 1.5 ppm chlorine leaving the site.

The limit, as provided in Technical Specification Appendix B, Section 2.2: is 0.2 ppm.

An environmental sampling run on June 8,1982, discovered several dead i

fish in the site discharge stream.

It was noted that live fish were l

also found in the area, so it is probable that the fish killed were lo-cated in the center of the stream where the chlorine concentration was highest.

As the flow moved further down stream it would dilute further. The maximum duration of the discharge was two hours.

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1 R H ENGELKEN June 14, 1982 It should be noted that, had the plant been operating, this situation would not have occurred, since the discharge volume would have been much greater, thus diluting the chlorine to tolerable levels.

The Plant Review Committee met on June 11, 1982, to evaluate this event. A corrective action was identified that will prevent such concentrated chlorine discharges in the future. The chlorine injection point will be moved from its present location at the suction of the circulating pump, to inject directly to the re-circulating inlet to the pond, thus bypassing the filters. This work will be done by October 1, 1982.

There were no transients associated with this event nor was the safety of the plant or public affected.

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x)f-Wm. C. Walbridge General Manager cc:

DCD, Washington

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