Speaker
Description
The development of Fusion Neutronics is closely related to Fusion Technology (FT) kicked-off in the 1970ies with the first tokamak reactor studies conducted then at the University of Wisconsin, Madison, in the US. Such studies necessitate the application of suitable computational tools, models and nuclear data to provide the nuclear responses required for assessing the nuclear performance of the considered reactor, in particular the tritium breeding, the nuclear power production and the radiation shielding capabilities. The underlying neutronic calculations were quite simple in those early times of FT, mainly based on one-dimensional S(N)-calculations using nuclear data from the ENDF/B-IV data file which already included some cross-section data for 14-MeV neutrons.
In the following decades a large number of power reactor studies were then conducted, notably in the US and in the EU with the European Fusion Technology Programme launched in 1983. Starting with the 1980s studies, the simple one-dimensional modelling approach was gradually replaced by the Monte Carlo method for the neutronics calculations. This enabled a more realistic modelling of the investigated reactor configurations and thus provided more accurate results for the nuclear responses, in particular the tritium breeding capability.
While the code development was mostly performed outside the fusion community, fusion specific activities were conducted in the experimental field with a series of integral 14-MeV neutron experiments for validating the neutronics calculations, but also differential neutron cross-section measurements in the fusion relevant energy around 14 MeV and beyond. In addition, dedicated efforts were conducted to establish qualified nuclear data libraries such as the Fusion Evaluated Nuclear Data Library (FENDL) of the IAEA.
With the launch of the ITER project, in the late 1989ies, and the IFMIF project for a high intense neutron source in the mid 1990ies, both with the objectives to build and operate the facilities, it became necessary to perform well qualified neutronics calculations satisfying also the safety requirements. This necessitated, among other, a very accurate geometry modelling based on detailed engineering CAD models and suitable methods for shut-down dose-rate assessments. ITER thus acted as driving force for related dedicated code and method developments.
The presentation briefly reviews the major developments in the field of fusion neutronics and highlights specific achievements in the computational and experimental area.