Activity emission model for VVER 440/213 reactor LOCA

A VVER-440/213 activity emission model has been developed in order to describe the activity release process in a case of a LOCA (Loss Of Coolant Accident) event. The model uses calculated and measured data. The pressure of the hermetic rooms in a LOCA event is calculated, the leakage from the hermetic rooms at certain pressure is measured, the model also considers the starting time of the fuel damage. For the estimation of the fission products release from the fuel damage the EUR conservative approach was used. The model also deals with filtering of the emitted fission products and considers the activity changes for the given nuclides by time. Three nuclides were used for our calculations. One noble gas 133Xe the behaviour of which is supposed to be similar to all other noble gases. The other two nuclides are very important from radiation protection point of view. For learning about short term contamination the 131I was chosen, for long term consequences the 137Cs was taken.