Natural circulation induced by the decay heat in primary loops of a molten salt reactor

A computer simulation is performed for the flow rates and temperature distributions in primary loops of a molten salt reactor. Equivalent pipes with proper diameter and length are used in this study to simulate fuel salt flow passages in the reactor, the main piping and the heat exchanger. Momentum and heat balances are considered in these pipes. By using this equivalent pipe model', the flow rates and temperature distributions in the primary loops are calculated in the case when the pump was stopped in an accident and the decay heat was released. The maximum temperature of about 925degC appeared in the fuel salt in the upper fuel path between reflector and reactor vessel at about 30 minutes after the reactor shutdown. (author)