581 



of the inherently low radioactivity release characteristics over a period of more than 

 two decades. 



Thus the Navy has attempted tolocate the SEA WOLF reactor vessel disposal 

 barge using the state of the art search capabilities within the Navy. 



This work was carried out primarily in 1979 during which approximately 27 days 

 of at sea search effort resulted in searching an area of approximately 36 square 

 miles centered on the recorded disposal location. The search of this area initially 

 detected numerous objects with the potential of being the barge. However, photo- 

 graphic examination of most of these indicated they were only large rocks or rock 

 outcropings present in the disposal area. Thus the barge has not been located. 



Question 3. (b) Please provide for the Subcommittee any information which you 

 may have available which would allow us to assess, in general, the potential impacts 

 of nuclear submarine reactors on the marine environment. 



Answer 3(b). As indicated in the answer to question 3(a), no significant effect on 

 the marine environment from the SEA WOLF disposal barge is expected. Informa- 

 tion to assess, in general, the potential and actual impacts on the marine eviron- 

 ment of nuclear submarine reactors is contained in an annual Navy report issued 

 by the Navy. This report is included each year in Congressional testimony and 

 published in the hearing record. This report shows that operation of the more than 

 100 Navy nuclear-powered ships and their support facilities has had no significant 

 effect on the radioactivity of the marine environment. 



More specifically, this report also provides pertinent information on the environ- 

 mental effect of the accidental sinking of two U.S. Naval nuclear-powered subma- 

 rines. The submarine THRESHER sank 10 April 1963, 100 miles from land in water 

 8,500 feet deep at latitude 41°45'N and longitude 65'"00'W. The submarine SCORPI- 

 ON sank between 21 and 27 May 1968, 400 miles southwest of the Azores in more 

 than 10,()00 feet of water. 



Radiation measurements, water samples, bottom sediment samples and debris 

 collected from the area where THRESHER sank were analyzed for radioactivity 

 shortly after the sinking and again in 1965 by various laboratories with highly 

 sensitive equipment. Similarly, sea water and bottom sediment samples taken near 

 scorpion's hull were analyzed for radioactivity. None of these samples showed 

 radioactivity above naturally occurring background levels, and none showed evi- 

 dence of radioactivity released from either THRESHER or SCORPION. 



In 1977, followup samples of water, sediment, marine life and debris were collect- 

 ed from the immediate THRESHER debris areas. In 1979, followup samples of 

 water, sediment, marine life and debris were collected from the immediate SCORPI- 

 ON debris areas. None of these samples showed any evidence of release of radioac- 

 tivity from the reactor fuel elements in either THRESHER or SCORPION. Howev- 

 er, cobalt 60 released from both THRESHER and SCORPION coolant systems was 

 detectable at low levels in sediment samples from localized areas which were not 

 sampled during the original surveys. The cobalt 60 radioactivity in these sediment 

 samples was small compared to naturally occurring radioactivity. Cobalt 60 was not 

 detectable in the samples of water, marine life or debris. Thus, the THRESHER and 

 SCORPION have not had a significant effect on the radioactivity in the environ- 

 ment. 



In this connection it should be noted the absence of significant environmental 

 effect for both the THRESHER and SCORPION exists even though both were lost in 

 a catastrophic manner with nuclear fuel installed. Should future sea disposal of 

 nuclear submarines be carried out, the nuclear fuel would be removed in all cases 

 and the submarine placed on the sea bottom in a controlled manner to enhance 

 compartment and system integrity. 



Enclosure (1) 

 DISPOSAL OF DECOMMISSIONED NAVAL NUCLEAR REACTOR PLANTS 



The U.S. Navy is currently conducting preliminary studies of alternatives for the 

 ultimate disposal of the defueled nuclear reactor plants of decommissioned nuclear- 

 powered submarines. Three submarines, the TRITON, HALIBUT, and NAUTILUS, 

 have been decommissioned and have been in protective storage since 1967, 1976, and 

 1979, respectively. The measures used to prepare these ships for protective storage 

 ensure that no radiological concern exists either to Navy personnel, shipyard em- 

 ployees, or the general public. 



When a ship is decommissioned, the nuclear fuel is removed and handled accord- 

 ing to established procedures for treatment of such material. With removal of the 

 fuel the uranium and fission products are also removed since they are contained 

 within the fuel. However, after the fuel has been removed, portions of the reactor 

 plant are still radioactive as a result of the operation of the nuclear reactor and 



