The impact of different temporal resolution rainfall data on biosphere model of long-term safety assessment in groundwater release scenario for radioactive waste disposal in the tropical monsoon zone

Abstract

The impact of different temporal resolutions of rainfall data on the Biosphere assessment for radioactive waste disposal in the tropical monsoon region with concentrated rainfall is evaluated in this research. Two scenarios are considered to verify the effect of release location. A simplified surface water budget model is used to generate the surface water flow rates for the biosphere model, which is implemented using three different temporal averaging intervals to consider the uncertainty caused by short-term impact. Kaohsiung in Taiwan is chosen as an example because of its extreme rainfall distribution. The results show that it is improper to use the annual rainfall data for this case, and it is suggested to consider a 20% margin to cover the underestimation of dose if the monthly rainfall data are used. The results of the biosphere models built with different timesteps show that a non-negligible difference occurs for radionuclides with a low Kd value in the river water release scenario and no difference for the well water release scenario.