This study was undertaken to demonstrate capabilities of the pin-by-pin model used by the BARS code and to understand various effects of intra-assembly pin-by-pin representation of fuel power, bumup and temperature in calculational analysis of light water reactor rod ejection accidents (LWR REAs). Effects of pin-by-pin fuel power and bumup representation were investigated on the basis of calcul...

The paper considers the efficiency and possibility of implementing into operational practice VVER-1000 power units campaign extension mode at sliding pressure second circuit. history research Russian nuclear scientists in terms extending VVER reactors is considered. It shown that reducing fresh steam within permissible limits will release additional reactivity due to temperature effect generate...

Reactor vessel internals are structures located within the reactor vessel that support and orient the reactor fuel assemblies and direct coolant flow through the core. The core basket is part of the internals structure, which consists of vertical plates that surround the outer faces of the hexagonal peripheral fuel assemblies. The vertical plates are bolted to the edges of horizontal former pla...

The first step in investigation of thorium fuel is evaluation of the results obtained from the spectral code for this type of fuel. The benchmark summarized by IAEA in 2003 was used for partial validation of the code HELIOS 1.9. The benchmark was focused on a comparison of the methods and basic nuclear data. Acceptable results of benchmark comparison allowed examining and comparing different ad...