Model for integral codes for calculating containment thermohydraulics in severe accidents at nuclear power plants with a water coolant

The article describes a model for calculating the containment thermal in severe accidents at nuclear power plants with a water coolant. The model is implemented in the SOCRAT integral code in the form of a CONT_TH module, which allows performing self-consistent calculation of parameters in a VVER reactor plant and a containment during a severe accident. In conjunction with other modules of the SOCRAT code, a realistic calculation of the transfer of radioactive substances to the containment is provided, which is necessary to calculate source term into the environment when justifying the safety of nuclear power plants, including probability safety assessment level 2. With a slight adaptation, the model can be used to calculate the parameters of containment in a water-cooled NPP as part of other integral codes.