CANDU 600 source term module for RODOS expert system

One of the most important input data for the analysis of consequences of severe accidents in a nuclear reactor is the source term. RODOS expert system is a real time on-line decision support system for emergency management of nuclear accidents in various types of nuclear reactors. A software has been built for the source term module for the case of a CANDU-6 reactor. It contains a menu guided graphical interface based on OSF/Motif. Our module was developed on the basis of an analysis of five severe accidents. Their frequencies and the isotopes released were taken into consideration in the following scenarios: - Late core disassembly with and without hydrogen burn; - Early core disassembly with hydrogen burn; - Partial melt; - Slow tritium release; - Moderator heat sink and containment bypass through Emergency Core Cooling System. Each selected type o severe accident has a frequency greater than 10-8 events/year. The estimated release values of 15 radionuclides in case of a late core disassembly with hydrogen burn is presented. The core inventory was calculated using ORIGEN program, at a burn-up rate of 7.5 MW.d.Kg-1. The first 14 isotopes are characteristic for RODOS system and tritium is added as a very important isotope released in a CANDU accident. Tritium is evaluated after 7.5 years of reactor operation