Research and Development on High-level Radioactive Waste and TRU waste

RWMC has conducted a variety of research and development on high-level radioactive waste(HLW) and TRU waste, such as a receiving system for returnable radioactive waste generated in the overseas reprocessing of spent fuel, management technology for high-level radioactive waste, prediction technology for super long-term movement of geological formations, and the business structure of the implementing entity. Through these activities, RWMC has been providing technical information to establish national policy and conducting research on safety standards and safety regulations.
In 2000, after the enactment of the Designated Radioactive Waste Final Disposal Act, the Nuclear Waste Management Organization (NUMO) was established and started its activities as the implementing entity for geological disposal of high-level radioactive waste. In consideration of this situation, RWMC has enlarged its activities to additional areas of practical research, such as investigation technology for a deep geological environment, remote operation technology, and socio-technology such as record preservation. RWMC in collaboration with universities has also been conducting basic and long-range research on the development of important basic technologies for geological disposal.
After the amendment of the Designated Radioactive Waste Final Disposal Act in 2007, the role of NUMO was enlarged to conduct geological disposal of TRU waste. In this area, RWMC has been conducting research on waste management concepts, processing and disposal technology, and the basic phenomena for performance assessment.
By carrying out these research projects, RWMC has been furthering the understanding of geological disposal.

●indicates currently active research

1.Research on Geological Environment

●Evaluation technology of the shape of seawater / freshwater interface and faults
●Development of geophysical technology, such as electromagnetic technique and elastic wave tomography for site selection process
●Tool to achieve traceability and transparency ,and accountability in geological environment investigation (the Site Investigation Flow Diagrams)

2.Research and Development on Disposal Technology

High-level radioactive waste
●Remote operation technologies, such as welding and inspection of overpack and transportation and emplacement of buffer material
●Retrieval technology of waste package (removing of buffer materials)
●Corrosion behavior of overpack weld joint and re-saturation process of buffer materials

TRU Waste
●Waste package to improve confinement of long-life radionuclide
●Immobilization technology of critical nuclide in radiation exposure evaluation,I-129
●Behavior of C-14 in activated metals
●Evaluation of long-term evolution and interaction of cementitious material and bentonite material
●Evaluation of gas migration behavior generated from waste

Welding test,TIG
Development of welding technology for HLW overpack lid closure

Assembling test

Transportation and emplacement test

3.Research on Criteria and Standards

・Methodology of safety check regarding acceptance of the returnable waste from the overseas reprocessing plants
・Classification and safety assessment of TRU waste
・Safety scenarios in TRU waste disposal
●Safety standards of geological disposal

4.Other Research

●Case study of natural analogues to explain safety of multi-barrier system
●Monitoring to confirm the basis of safety of repository
●Wireless transmission monitoring technology for geological disposal facilities
●Record preservation in geological disposal

5.Promotion to Understanding of Disposal

・Brochures for public relations
・Workshops on radioactive waste disposal
●Full-scale demonstrating exhibition for ensuring, and understanding a concept of geological disposal of HLW, technical feasibility of repository operation technology and long-term behavior of engineered barrier