One of the main objectives of CIEMAT is to offer scientific-technical support for current and future decision-making in Spain, through participation in both national and international R&D projects. In this sense, the High Activity Waste Unit (URRAA/HLWU) has been working for more than twenty years to achieve adequate management of Spent Nuclear Fuel (SNF), seeking sustainability and social acceptance of the cycle of nuclear fuel, in collaboration with ENRESA, and has provided useful information on the management of the waste generated. In recent years, the greatest efforts of the URRAA/HLWU have focused on the physical-chemical characterization of radioactive waste and innovation in the field of new types of fuels. In addition, the research group has unique facilities in Spain for handling and analyzing nuclear material (IR-30 and IR-35 Radioactive Facilities, the latter in the licensing process) that enhances the unique CIEMAT experimental facilities. On the other hand, conventional laboratories (also referred to as “cold” laboratories) are available for surface characterization techniques without radioactive isotopes or “exempt” radioactive material, dissolution and manufacturing tests, as well as for synthesis, purification and analysis in cold analysis of organic ligands included in all radionuclide separation processes.
Photo of High Level Waste Unit's (HLWU) team.
Currently, the main scientific-technical areas of HLWU include the next research lines:
Fabrication, conversion and characterization
Fabrication and characterization of advanced fuels, high density fuels, irradiated fuels, and analogues of irradiated fuels. Development of innovative process and preparation methods of ATF materials and ceramic transmutation blankets (waste minimization targets).
Long-term evolution of High-Level Radioactive Waste (spent/irradiated nuclear fuels, SNF) under different repository conditions
Characterization of irradiated nuclear fuel and high level wastes (both packaged and conditioned solid wastes) and its stability under temporary or repository storage conditions, focussing on its alteration and its potential subsequent radionuclides release. Behaviour and safety of SNF at present reactors or of enhanced safety (ATF) during transport, dry storage, or final disposal.
Development of long-lived radionuclides separation processes for advanced nuclear fuel cycles
Research and optimization of new liquid-liquid extraction processes for the recycling of long-lived minnor actinides (MA) in two scenaries: an heterogeneous recycling (Am/Cm) to obtain dedicated fuel or targets with a high proportion of An; the recovering of all An together (Pu, Am, Cm, Np) for an homogeneous recycling as part of mixed oxide fuel (UO2-An) keeping a low percentage of An. The long-term behaviour of new extraction systems and safety requirements at the industrial is comprised, and also optimization of conversion systems.