544 



5. The rates of release of radioactivity to the oceans can 



be reduced by suitable containment and packaging of wastes. 

 When it has been established that wastes can be contained 

 for a given length of time, an allowance for decay in 

 situ, relative to that time may be considered. Emplacement 

 of waste canisters into certain seafloor sediments may pro- 

 vide additional containment and should be further investi- 

 gated . . 



20 



The movement within IAEA toward waste disposal systems that achieve isola- 

 tion and containment of wastes, the acceptability of which are based on 

 the release rates from such dispositions instead of the nature of the 

 substance deposited, weakens the basis of the legal prohibition against 

 the disposal of HLW although of course it does not eliminate it. 



The prohibition against disposal of HLW at sea under the Convention 

 is based on an administrative rather than a technical rationale, since as 

 noted in the IAEA consultants' report, there is no scientific reason why 

 HLW should be treated differently from non-HLW, provided the release rates 

 do not exceed acceptable maxima. The administrative rationale for treating 

 HLW differently fron non-HLW is the assumption that the release of the sub- 

 stances contained in HLW could easily exceed the maximum acceptable rates 

 for such substances if there were a failure of containment devices. HLW, 

 because of its radiological, chemical, and thermal characteristics, is also 

 more likely to escape from conventional containment. If the nature of the 

 methods of disposition were such that virtually complete isolation of the 

 wastes in question could be assured for the necessary time, however, then 

 there would be no administrative rationale to prohibit all oceanic disposal 

 of HLW but allow continued disposal of LLW. 



