According to the report "Radioactive Waste Disposal from U. S. 

 Naval Nuclear-Powered Ships", the actual operating results of the 

 U. S. S. NAUTILUS and the U, S. S. SKATE have produced radioactive 

 wastes considerably less, both in intensity of activity and in amount, 

 than those predicted in the Maritime Administration's report for the 

 SAVANNAH. The average gross activity of the primary coolant of the 

 NAUTILUS, 15 minutes after sampling, was 5 x 10"^iic/ml. However, 

 the bulk of this activity was associated with Mn 56 (2.5 hr half life) and 

 F 18 (1.9 hr half life). The gross activity 120 hours after sampling has 

 averaged 3 x 10"^ ^c/ml. The measured activity of Co 60, Fe 59, and 

 Ta 182 has averaged 5.7 x 10-^ , 1.5 x lO'^, and 7.3 x 10-3 ^c/ml re- 

 spectively. Fe 55 apparently does not occur in measurable quantities in 

 the primary coolant of the NAUTILUS. 



The expansion volume on warm-up for the NAUTILUS is much 

 less than that predicted for the SAVANNAH, averaging about 500 gals 

 (67 cubic feet). The maximum activity on the spent ion exchange resins 

 in the NAUTILUS, and the rate at which these resin beds require re- 

 placement, are likewise much less than the corresponding figures for 

 the SAVANNAH. The total activity on the spent resin beds is reported 

 to be no more than 12.5 curies, with the bulk of the activity (some 10 

 curies) resulting from Co 60. The beds have required replacement 

 about once every six months. 



During each warm-up involving the average discharge of 67 ft3 

 or 1.9 X lO^^ml, the NAUTILUS then releases approximately 9.5 x lO^^ 

 curies (measured 15 minutes after sampling). Co 60, Fe 59, and Ta 182 

 would contribute 1.1 x 10'^ curies, 2.9 x lO*"^ curies, and 1.4 x lO^^ 

 curies, respectively. Assuming two warm-ups per month, the total 

 activity in the expansion volume liquid wastes from the NAUTILUS 

 during one year would be about 2.3 curies ntieasured 15 minutes after 

 sampling and 0.14 curie measured 100 hours after sampling. 



In comparison with these amounts, the activity in the fission prod- 

 ucts contained in the spent fuel elements is quite large. Thus the fis- 

 sion products in the fuel elements from a 60 MW reactor which had 

 been in service for one year on a nuclear-powered ship would amount 

 to over 10^ curies. 



It has been stated that the vast majority of the fission product 

 wastes will be stored on land, after chemical separation from unused 

 fuel and useful by-products. However, even a small fraction of this 

 activity could be significant if released in coastal areas. Release of 

 activity to the coastal environment by land based nuclear installations, 

 particularly chemical processing plants, may be difficult to avoid. 

 Thus, under a carefully controlled program designed to limit the re- 

 turn of activity to man to a safe level, the Windscale Works in England 

 is authorized to release over 10 5 curies per year into the coastal 

 waters of the Irish Sea. The major part of the safe capacity of these 

 inshore areas should then be reserved for land based operations, since 

 nuclear-powered ships could conceivably delay discharge of wastes 

 until outside such areas. 



