A Study of direct disposal technology in the world

not registered; Okubo, Hiroo*

There are two methods of handling the spent fuel generated from the light water reactor; they are (1)direct disposal and (2)reprocessing-plutonium recycling. At present, Japan is following the line of "Reprocessing-Plutonium Recycling," but in the rest of the world, the movement for reviewing the plutonium recycling is spreading, and in the future, the world opinion and pressure from overseas countries will increase against this method. Under these circumstances, Japan must compare the two methods to clarify the meaning of plutonium recycling. For this reason, the present investigation first studied the concept and trend of spent fucl disposal in overseas countries to find out what factors were regarded as important in the spent fuel policies of various countries. Further, in the present investigation, comparative evaluations were made on the results of examinations in various countries regarding "direct disposal." Examinations have also been made as to whether there is a significant merit or demerit in direct disposal and plutonium recycling, and whether it is possible to generally apply the direct disposal method adopted in overseas countries to Japan. The investigation has revealed that there are factors such as techniques, energy, resources, economy, environment, institutions, safety, etc., which influence the spent fuel disposal policy. The five countries including the United States and Sweden, which have clearly taken up the direct disposal policy have so by laying importance on different factors according to the situations of the respective countries. Further, the comparative evaluation concerning the economy, safety, etc. has shown small difference between direct disposal and plutonium recycling and neither has any significant merit or demerit. Further, regarding the disposal concept, there are great differences according to the actual states of various countries; hence it is considered that Japan should carry out comparative evaluation of direct ...