Development of the methodology on priority of element-specific biosphere parameters for geological disposal applicable to any proposed repository site

Kato, Tomoko ; Suzuki, Yuji*; Oi, Takao 

It is difficult to acquire all of biosphere parameters at the repository site because we have to deal with several hundreds of the parameters in one calculation case of the biosphere assessment. Before site-specific activities, it is important to develop the data acquisition methodology of biosphere parameters applicable to any proposed repository site. In this study, we developed the methodology for identification of the priority of the parameters for the effective data acquisition of biosphere parameters at the site. First of all, flow diagram was constructed to evaluate the availability of the existing generic biosphere dataset. We found that it was effective for the data acquisition at the site to focus on the element-specific parameters with the existing dataset. Secondly, we identified the priority of the data acquisition for element-specific parameters at the site, with considering the variation of radiation dose by combining the significant element-specific parameters. As a result, we identified the availability of the existing generic biosphere dataset and the priority on data acquisition of the element-specific parameters of key radionuclides in the safety assessment of geological disposal that should be acquired at the site. This priority list would be useful for effective data acquisition at the site.