In the aftermath of the Fukushima Daiichi accident, NEA joint projects supported by participating member countries and the Government of Japan have delivered cross-cutting safety research in decommissioning research and development, as well as in the improvement of scientific understanding and modelling capabilities addressing severe accident progression and consequences.
The joint project on the Thermodynamic Characterisation of Fuel Debris and Fission Products Based on Scenario Analysis of Severe Accident Progression at Fukushima Daiichi Nuclear Power Station (TCOFF) was established in this context in 2017 under the umbrella of the NEA Nuclear Science Committee (NSC). Supported by the Japan Atomic Energy Agency (JAEA) Collaborative Laboratories for Advanced Decommissioning Science (CLADS), the project focused on the integration of improved knowledge of the thermodynamics of severe accidents into severe accident analysis codes.
After TCOFF successfully completed its first phase in July 2020, the second phase of the project with an extended scope is currently being prepared. A preparatory meeting was held on 17 May 2021 to discuss potential tasks for the TCOFF Phase 2 and define their scope.
While the first phase of the project focused on the evaluation of the Fukushima Daiichi accident from a materials science perspective, TCOFF-2 will focus on improving the integration of the material science into the simulation of the severe accident phenomena at the meso- to integral- scale. In its second phase, the project will also collaborate with the Nuclear Education, Skills and Technology (NEST) Framework, which aims to build up skills vital for the future of the nuclear sector through multilateral co-operation.