ML19282A142
| ML19282A142 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 05/08/1979 |
| From: | Ward E NORTHERN STATES POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 7905140214 | |
| Download: ML19282A142 (1) | |
Text
MSP NORTHERN STATES POWER COMPANY M IN N E A PO LO S, M O N N E SOTA 55400
~
May ?, 1979 Mr J G Keppler, Director, Regica III Office of Inspection & Enforcement U S Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Dear Mr Keppler:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket No. 50-282 License No. DPR-42 50-306 DPR-60 Environmental Event Report 79-03 Cooling Tower Operations Blowdown Flow During River High Uater Unde r TS B-5.4.2. A, we are furnishing two copies of this Environmental Event Report covering operation of the plant circulating water system with uncontrolled blowdown flow for the nine day period of April 24 through May 2.
Referring to TS B Figure 3.1.2-1, the blowdown flow is controlled by maintaining a small head of water in the gate (or weir) structure located at the upstream edge of the discharge canal.
From April 24 through May 2, 1979, with the river elevation above 680 ft., the gate structure was under water so there was no way to control or measure blowdown flow.
During this high-water condition, a greater portion of the water discharged from the cooling towers flows directly to the river rather than back up the recirculation canal to the plant intake. Under this condition the cooling tower system operates partially in a closed cycle, and partially in a helper cycle mode.
With the high-water condition now subsided, control and monitoring of the blowdown flow has been restored.
Prior to and following the period of high water, the daily average blowdown flow did not exceed 150 cfs.
Yours very truly, t2s N
i s b
( t, [Lh E C Ward, PE Manager-Nuclear Environmental Services ECW/jh cc Director, NRR c/o DSB (17)
MPCA d
D Att: J W Ferman 1905140 AIT ft