Development of the assessment tools for land use scenarios concerning sub-surface disposal

The safety assessment of the sub-surface disposal system should ensure that calculated dose will be lower than the dose assigned to the scenario in question over the whole evaluation period of hundreds of thousands years. In order to realize the safety disposal, we have developed several assessment tools on the GoldSim platform and calculated doses since 2008, and these assessment tools have been improved reflecting the last view of assessment. This report describes idea of assessment models and structure of assessment tools for land use scenarios. Land use scenarios involve direct or indirect contact with radioactive materials contained in rock or in the disposal facility which has come close to the ground surface due to uplift/erosion or sea level changes, or contained in rock/soil along groundwater flow paths and at the flow output in the biosphere. (author)