Plan and technical development status of disposal of low-level radioactive waste generated from research facilities

Sakai, Akihiro 

Plan of disposal of LLW generated from research facilities and recent topics of technical development of the disposal are explained. At first, regarding the radioactivity evaluation of waste, a study about the reduction of the number of important nuclides by the method that enhances the safety functions of the trench disposal facility is introduced. The installation of impermeable layers and sorption layers in order to reduce the leaching of nuclides and the installation of a cover structure with resistance to human intrusion into the waste layer are examined as the safety functions. Then, regarding the design and operation of trench disposal facilities, a measure that increase the slope angle of the cover soil beforehand is explained in order to prevent the cover soil from settlement caused by voids in the waste containers at the trench disposal facility. We will continue to study the specific design of trench disposal facilities to realize the measures to these issues.