conjunction with a larger program to evaluate the feasibility of backfit- 

 ting fish-return sluiceways into the fish/trash collection systems at 

 Units 1 and 2. Unit 3 presently has plans for a similar fish-return 

 system. Initial and extended (60-h) survival estimates for the 1980-81 

 study were found to be higher than those of 1977. The dissimilarities 

 between the reports may be attributable to differences in sample size, 

 seasonality of the data, or improvements to the sampling procedures 

 which eliminated all stresses on the organisms except those attributable 

 to impingement (NUSCo 1981b, 1982). Similar studies done at Bowline 

 Point Generating Station, N.Y. (O&RU 1977) and at Oyster Creek Generating 

 Station, N.J. (JCP&L 1981) showed that survival estimates there were 

 generally similar to ours (NUSCo 1981b) . The conclusion of the sluiceway 

 study was that fish and shellfish losses at Unit 1 could be reduced in a 

 cost-effective manner with the addition of a sluiceway there. However, 

 construction of a sluiceway at Unit 2 was not cost-beneficial. 

 Conclusion 



Routine impingement monitoring at Millstone together with the 

 numerous special studies, have provided quantitative data characterizing 

 impingement at the site. Adjustments to the field sampling aspects of 

 the program have been made without signif iciant loss of information. 



Reductions in impingement mortalities and reductions in sampling 

 effort will result when a sluiceway is installed at Unit 1. Further 

 reductions in impingement sample effort of up to 40% are feasible at 

 Unit 2 while maintaining the current level of precision. 



For the future, the following programs are proposed: 



1) evaluation of Units 1 and 3 sluiceway effectiveness, 



16 



