In this report, prepared for the Entergy Pilgrim Nuclear Power Station in Plymouth, Massachusetts, a NERA team led by Senior Vice President and Environment Group Head Dr. David Harrison analyzes the costs and benefits of additional technologies that might be used at the Pilgrim Nuclear Power Station to reduce mortality of marine life caused by the plant's intake of cooling water. Technologies considered included a hybrid wet-dry cooling tower (which would form part of a potential “assisted recirculation” system) and variable speed pumps. The comprehensive cost assessment included detailed evaluation of the costs due to reduced power output from the facility, in addition to the capital and operation and maintenance costs associated with the potential technologies. The benefits assessment considered gains to recreational and commercial fisheries based on biological and economic modeling. The report also considered potential effects on the electricity system as well as well as the tradeoffs that implementing these technologies would entail with climate change and air quality objectives.