in the service water systems. In a letter from W. Romberg to R. Herbert, 

 dated 4 December 1981, Wayne wrote, "Disassembly of the service water 

 strainer on November 27, 1981 again revealed that the MP-1 chlorination 

 system does not adequately protect the service water system from mussel 

 growth". Ray Palmier i informed us that between August 1980 and October 

 1981, various heat exchangers in the Unit I service water system were 

 opened 74 times to remove mussels and debris. In an attempt to reduce 

 fouling and improve seawater system reliability, Unit II is presently 

 continuously chlorinating their service water. Holmes (1970; The effects 

 of chlorination on mussels. CERL RD/L/R 1672) reported that marine 

 fouling could be prevented with continuous chlorination at 0.5 mg/1, and 

 Marine Research, Inc. , in a 1980 report to the Electric Power Research 

 Institute (EPRI EA-1588; Selected alternatives to conventional chlorination) 

 found that continuous low-level chlorination (0.1 mg/1) prevented the 

 attachment of mussels. 



Accordingly, we have made a series of recommendations to Plant 

 Operations. One involves continuous chlorination of the service water 

 system of both Units I and II. This procedure would require modification 

 of existing Tech. Specs., which restrict simultaneous continuous chlori- 

 nation. The change request has been submitted to NRC, but will probably 

 not be acted upon if responsibility for non-radiological environmental 

 monitoring is transferred to the state DEP. 



Pending the outcome of the NRC hearing, some recommendations maximize 

 biofouling control within present permit limitations, e.g., by partitioning 

 the chlorine to increase the concentration in the service water system 

 (which cannot be thermally back-flushed) . Unit I in particular could 

 increase dosage time considerably, and still maintain an 'intermittent' 

 schedule. 



