84 TRANS URANIC ELEMENTS IN THE ENVIRONMENT 



3. After being launched in April 1970, the Apollo 13 was aborted in flight, and 

 44,500 Ci of ^^*Pu (33 Ci of ^^^Pu) attached to the lunar landing vehicle was 

 deliberately disposed of in the Pacific Ocean near the Tonga Trench as a preplanned flight 

 contingency. 



All the above aborts were identified and their probabilities and consequences were 

 analyzed in the risk assessments submitted for the pre flight presidential approval actions. 



The space program has handled approximately 1 MCi of plutonium, and only 17,000 

 Ci has been released to the environment as worldwide fallout. The activity disposed of in 

 the deep ocean is contained in corrosion-resistant materials that should prevent the 

 release of the fuel for a period of time equivalent to 10 half-lives of the ^^^Pu fuel. 

 Safety design requirements have been established which limit the release of fuel to the 

 environment. Since accidents are not expected to occur each time a system is launched 



TABLE 1 Summary of Launched Space Nuclear Power Systems 



