Characterization of the gfr2400 reactivity effects

The present paper deals with characterization of the two main reactivity effects of the GFR2400 core: coolant void effect and Doppler Effect. In special cases, it is necessary to follow not only temperature rising over nominal conditions but for GFR 2400 the main problematic area is likely situated close to zero power conditions. Integral values of Doppler and void effects are easily evaluated by static calculations, but in this paper spatial distribution and isotope decomposition for chosen effects are also introduced. Designers could benefit from the obtained data either in case of optimization of these reactivity effects or in case of transient analyses. (authors)