IMPACT ASSESSMENT FOR WINTER FLOUNDER 

 The primary means of assessing impact of the Millstone Nuclear 

 Power Station on the winter flounder to date has been a deterministic 

 model developed by the University of Rhode Island. It assesses the 

 effects of entrainment as impingement losses are of lesser potential 

 importance, particularly after installation of sluiceways. This model 

 has been evaluated as an acceptible but conservative method of estimating 

 impact (Gore et al. 1977; Thomas et al. 1978). It has been used as 

 recently as this year in the Final Environmental Report for Millstone 

 Unit 3, which is currently undergoing revision before submission to the 

 U.S. Nuclear Regulatory Agency. 



The model is described and critiqued in detail by Saila (1976). 

 Portions of this work have also been published (Hess et al. 1975). The 

 model assumed that the Niantic River was the source of all larvae entrained 

 at Millstone and estimates of their annual losses were projected over 

 the life of the plant. The primary reason for much of the research 

 conducted on winter flounder at Millstone was to provide data needed for 

 the model and to verify aspects of it. 



Recent advances in impact modelling have made this model less 

 acceptible for impact assessment. A deterministic model gives results 

 applicable only for those particular sets of data or values input. 

 Today more advanced stochastic models have been derived to estimate 

 impact which take into account the random and natural variability of 

 elements of the population and are much more realistic than deterministic 

 models. For these reasons a stochastic matrix model developed by the 

 University of Rhode Island for impact assessment was accepted during the 

 1982 Millstone Ecological Advisory Committee meeting as the basis for 



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