Vulnerability and Survival of Young Connecticut River Fish Entrained at a Nuclear Power Plant
Most of the young fish of nine species that were entrained in the condenser cooling-water system of the Connecticut Yankee nuclear power plant were dead by the time they reached the lower end of the plant’s 1.83-km (1.14 mile) long discharge canal. Sampling during June and July, when 95% of the nonscreenable fish were abundant near the plant’s intake, showed that approximately 80% of the mortality in the canal was caused by mechanical damage and 20% was attributed to heat shock and prolonged exposure to temperatures elevated above 28 C. There was no measurable mortality due to the injection of sodium hypochlorite into the system as a biocide. The number of nonscreenable living fish entrained at the intake averaged about 4% (range, 1.7–5.8%) of those passing by the plant under conditions of unidirectional net tidal flow.