Assessment of soil-soil solution distribution coefficients of global fallout Np and Pu in Japanese upland soils.

Neptunium-237 and Pu are important radionuclides in the safety assessment related to geological disposal of radioactive waste because of the possibility of long-term exposure to humans. Mobilities of these radionuclides in the environment are of particular importance for their radiation dose evaluation; therefore, in this study, we have made the assessment of the soil-soil solution distribution coefficient (K, L/kg) using global fallout Np and Pu in Japanese upland soils. The K values were determined by extracting these radionuclides from 24 soil samples using a laboratory batch method.

Approaches to the definition of potentially exposed groups and potentially exposed populations of biota in the context of solid radioactive waste.

A methodology for addressing the biosphere in safety assessments for solid radioactive waste disposal was developed through theme 1 of the IAEA coordinated research project on BIOsphere Modelling and ASSessment (BIOMASS) that ran from 1996 to 2001. This methodology provided guidance on how the biosphere can be addressed in safety assessments for disposal of solid radioactive waste. Since the methodology was developed, it has proven useful and has been widely referenced in assessments in a diversity of contexts encompassing both near-surface and deep geological disposal of solid radioactive waste.

Safety assessments undertaken using the BIOMASS methodology: lessons learnt and methodological enhancements.

The International Atomic Energy Agency has coordinated an international project addressing enhancements of methods for modelling in post-closure safety assessments of solid radioactive waste disposal. The project used earlier published work from the IAEA biosphere modelling and assessment (BIOMASS) project to further develop methods and techniques. The task was supported by a parallel on-going project within the BIOPROTA forum.

Soil-soil solution distribution coefficients of global fallout Pu and Np in Japanese paddy soils.

Pu and Np are long-lived radionuclides that emit alpha rays, and once released into the environment, they are present there for a long period of time. Therefore,Pu and Np are important radionuclides in the safety assessment related to geological disposal of radioactive waste because of the possibility of long-term exposure to humans. Mobilities of these radionuclides in the environment are of particular interest; therefore, in this study, we have made the first-time determination of the soil-soil solution distribution coefficient (K, L/kg) using global fallout Pu and Np in soil.