303 



Mr. Studds. In what way has the Department of Energy been 

 involved in the search for it, and what damage might have ensued 

 from it? 



Mr. Meyers. As best I understand it, the environmental effects of 

 disposal of that particular irradiated pressure vessel are practically 

 nil. The prime source of radioactivity is cobalt 60 which is an 

 integral part of the metal and has a half-life of some 5 years. This 

 means that in 10 half-life periods the radioactivity will be reduced 

 to innocuous levels. In the last 20 years, the significant radioactiv- 

 ity has decayed away. 



Mr. Studds. Has the Department of Energy been involved in the 

 search for, or a study of that vessel? 



Mr. Meyers. I believe the Department, through our naval reactor 

 program, has given technical support. I will provide, now, addition- 

 al Seawolf disposal information. 



[The following was received for the record:] 



The Disposal of the USS Seawolf Reactor 



The first reactor in the USS SEAWOLF was a liquid metal intermediate range 

 power reactor and was not a breeder reactor. Although the original reactor plant 

 operated satisfactorily for approximately two years, it was replaced with a pressur- 

 ized water reactor because the liquid metal type of reactor plant was determined to 

 be unsuited for continued submarine application. The weight savings that had been 

 sought in using the more compact liquid metal design was lost due to the need for 

 additional shielding. With a water-cooled reactor the reactor compartment can be 

 entered to make repairs after the reactor is shut down. With a liquid metal plant 

 there is a considerable delay time which was considered undesirable for a warship 

 which might suffer battle damage requiring immediate repair. There was also a fire 

 hazard with liquid sodium which can react with water creating an additional hazard 

 in a submarine application. 



The reactor was designed by the Knolls Atomic Power Laboratory. General Elec- 

 tric was the primary manufacturer. 



The USS SEAWOLF reactor plant was disposed of at sea. On April 18, 1959 the 

 radioactive reactor vessel and reactor plant components from the sodium-cooled 

 nuclear reactor plant in the submarine SEAWOLF were escorted by the U.S. Coast 

 Guard to a disposal site in the Atlantic Ocean 120 miles off the East Coast of the 

 U.S. and sank in 9,000 feet of water at latitude 38°30'N and longitude 72°06'W. The 

 expended nuclear fuel was not disposed of at sea but was shipped to special Govern- 

 ment facilities for processing in the same manner as for other expended nuclear 

 fuel. The disposal was conducted at a site approved for sea disposal of radioactive 

 waste by the U.S. Atomic Energy Commission. This disposal site was used by other 

 organizations for a number of years for radioactive waste as noted in a report issued 

 by the U.S. Council on Environmental Quality (Ocean Dumping, A National Policy, 

 October 1970). 



The radioactivity was sealed within the heavy steel reactor vessel for disposal. 

 The radioactivity was restricted from release not only because it was located inside 

 the reactor vessel but because it was further contained as an integral part of the 

 corrosion resistant stainless steel internal reactor vessel structure. A release into 

 the surrounding area would be expected to occur only due to corrosion of both the 

 reactor vessel followed by slower corrosion of the stainless steel. Furthermore, the 

 products of corrosion of the steel are primarily solid rust-like materials which are 

 extremely insoluble in sea water and therefore tend to remain attached to the metal 

 surfaces or remain locally on the bottom sediments. 



The total amount of radioactivity was approximately 33,000 curies and was pre- 

 dominantly cobalt 60, which has a 5 year half-life. In the twenty-one years since 

 disposal the radioactivity has decayed to less than one-tenth its original value. 



In summary, the radioactivity should remain within the SEAWOLF reactor vessel 

 while it decays away and no significant effect on the marine environment is expect- 

 ed. 



Source: Provided by Chief of Naval Information, U.S. Navy. 



