An overview is given on research activities on cementitious materials for radioactive waste management systems based on the IAEA Coordinated Research Project (CRP) held in 2007-2010. It has been joined by 26 research organizations from 22 countries which shared their research and practical activities on use of cementitious materials for various barrier purposes. The CRP has initially formulated the research topics considered within four specific streams: A) Conventional cementitious systems; B) Novel cementitious materials and technologies; C) Testing and waste acceptance criteria; and D) Modelling long term behaviour.
The CRP has analysed both barrier functions and interactions envisaged between various components with focus on predisposal stage of waste management. Cementation processes have achieved a high degree of acceptance and many processes are now regarded as technically mature. A large body of information is currently available on proven waste conditioning technologies although novel approaches are continuing to be devised.
Most of the existing technologies have been developed for conditioning of large amounts of operational radioactive waste from nuclear power plants and other nuclear fuel cycle facilities. However new waste streams including those resulting from legacy and decommissioning activities required improved material performance and technologies.
The most important outcome of CRP was the exchange of information and research co-operation between different institutions and has contributed towards general enhancement of safety by improving waste management practices and their efficiency. The paper presents the most important results and trends revealed by CRP participants. The research contributions of participating organizations will be published as country contributions in a forthcoming IAEA technical publication.