Actinides associated with particles

Abstract

Following nuclear events such as nuclear weapons tests and nuclear accidents, particles containing actinides are released into the environment. Furthermore, actinides associated with colloids and particles are present in effluents from nuclear installations during normal operations. Thus, the presence of radioactive particles in releases from nuclear sources occurs more frequently than is usually anticipated. The composition of radionuclides in particles is, however, source-related, while particle characteristics related to microstructures also depend on release conditions and dispersion processes. Thus, source-term information on actinide speciation, e.g. size distribution pattern, crystallographic structures, binding mechanisms and oxidation states, influencing weathering rates and mobilisation of associated radionuclides in ecosystems is essential for impact assessments. For areas contaminated with particles, impact assessments will suffer from unacceptably large uncertainties unless the impact of particles is taken into account. Therefore, advanced analytical micro-techniques applicable to particle characterisation are greatly needed within radioecology. The present work summarises the available literature related to actinide-containing particles released from specific nuclear sources.