ML19095A814

Reporting Incident During Thermal Limitations on Condenser Cooling Water Discharge Were Exceeded

ML19095A814
Person / Time
Site:	Surry
Issue date:	07/23/1975
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	Goller K Office of Nuclear Reactor Regulation
References
Serial No. 609
Download: ML19095A814 (1)

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• Mr. K. R. Goller, Assistant Director Serial No. 609 for Operating Reactors PO&M/JTB:clw Division of Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-280 U.S. Nuclear Regulatory Commission 50-281 Washington, D. C. 20555 License ~OS, DPR~32 DPR-37

Dear Mr. Goller:

In accordance with the Surry Power Station, Unit Nos. 1 and 2, Technical Specifications, this is to notify you of an incident during which the thermal limitations on the condenser cooling water discharge were exceeded.

The incident occurred on July.11, 1975 while escalating power on Unit No.

2 following a unit start-up. The unit was at approximately 48 per.cent of rated thermal power and 340 MWe. At this time during the power escalation, two circulating water pumps were.started and the condenser outlet valves positioned to maintain intake canal level. Subsequent monitoring of the cir-culating water temperatures revealed that .the increase in flow thro_ugh .the condenser caused the temperature at the discharge control structure to decrease 3.5 degrees Fin approximately fifteen (15) minutes. There was no.further de-crease in the discharge temperature during the hour. Technical Specification 4,14.A.3 requires that the cooling water temperature at the discharge control structure not exceed an average *rate of change of 3 degrees F per hour. There was *no evidence of any adverse environmental impact caused by the incident.

Analysis of the occurrence indicates that the rate of circulating water flow through the condenser was increased too rapidly. In order to prevent recurrence, operating personnel have.been instructed to exercise more caution when operating the condenser water boxes and to monitor the circulating water

.temperatures closeiy during the operation. The operating procedures *for the circulating water system are being revised to.reflect these precautions and to limit starting of the circulati~g water pumps to one at a time at sufficient intervals to avoid exceeding the maximum rate of change of temperature at the discharge c~ut~structure.

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