The SIMCO containment code applied to modeling hydrogen distribution in containments of nuclear power facilities
The general description of the SIMCO code developed for modeling of thermo-hydraulic and physical and chemical processes in the containment is submitted. The calculation procedure on the basis of physical and mathematical model in the lumped parameters is presented. Lumped parameters codes are based on the fundamental assumption that within a chosen volume, called a control volume, spatial differences of thermohydraulic variables - like fluid density, concentration and temperature - are neglected. While only the time-dependent behaviour is represented in conservation equations that describe containment transport processes. As a numerical method the modified semi-implicit SIMPLER procedure is used. Testing of a code on the basis of analytical and qualitative tests is held. A good agreement of calculation and analytical solution is obtained for the analytical test. Verification of a code on the experimental data obtained at the NUPEC installation (Japan) is executed. ISP-35 - hydrogen mixing and distribution test M-7-1, performed by Nuclear Power Engineering Corporation (NUPEC, Japan). NUPEC's hydrogen mixing and distribution test M-7-1, was conducted as a part of the Proving Test on the Reliability for Reactor Containment Vessel Project. The NUPEC model containment at the Tadotsu Engineering Laboratory consists of a one-quarter linearly scaled PWR dry, insulated steel containment vessel with a free volume of 1300 m<sup>3</sup>. The purpose of the hydrogen mixing and distribution test, part of the program to evaluate containment integrity, was to investigate hydrogen distribution phenomena in a model containment and to validate analysis codes. By results of testing and verification it is possible to draw a conclusion that in general physical and mathematical models of a code rather adequately describe processes of a heat-mass transfer in protective shells. In this regard this version of the SIMCO code can be used for the analysis of set of thermo-physical and chemical processes in the containments and protective shells of nuclear power facilities, including steam-air-hydrogen mixtures distribution.