Following the 2011 accident at the Fukushima Daiichi Nuclear Power Plant, improving the quality and inventory of thermodynamic databases used for severe accident analyses has been an important area of joint research efforts for the international nuclear community.
Following the success of phase one the TCOFF project in 2020, the second phase of the Nuclear Energy Agency’s (NEA) joint project on the Thermodynamic Characterisation of Fuel Debris and Fission Products Based on Scenario Analysis of Severe Accident Progression (TCOFF-2) has commenced, with an inaugural meeting taking place in Tokyo, Japan on 2-3 February 2023.
The meeting gathered 40 international experts to discuss the project objectives and to set timelines. In particular, the discussion of the prioritisation of material science issues related to severe accident studies progressed, as this first task will guide the call for R&D proposals that will be issued in 2023 to tackle:
- Integral tests or separate effect tests for the validation of prioritised phenomena modelling;
- Co-development of models and experiments for their validation;
- Fission product and multi-component system experimental measurements for the purpose of thermodynamic database improvement.
The TCOFF-2 project aims to improve the models describing the material interactions and the role they play in the various phases of the severe accidents. The goal is to increase the accuracy of such models in severe accident simulation codes. This improvement will be driven in particular by state-of-the-art knowledge of the thermodynamic properties of the material systems relevant to the description of core materials degrading through a severe accident sequence. This knowledge, partially developed and accumulated during the execution of the first phase of the TCOFF project and previous international efforts, will be systematised and further extended in this second phase of TCOFF through joint expert evaluations, thermodynamic modelling and focused R&D efforts.
For more information on the NEA’s work on materials science visit here.