Reliability modeling of primary cooling system for estimating probability of loss of cooling flow in research reactor RSG-GAS

Probabilistic Safety Assessment (PSA) is a standard method which is often used in evaluating the safety of nuclear installations such as power reactors and research reactors. The first step in the PSA is to determine the initiating event that can initiate a series of possible accidents that have effects ranging from the most insignificant to the most significant. One example of an initiating event that is crucial and likely to occur in the operation of research reactors is the loss of coolant flow. This event should be anticipated as well in order not to lead to accidents that have an impact on safety. One way to anticipate this event is to know the probability and the main cause of the incident. Because this event is basically a failure of the Primary Cooling System at the time of the reactor is operating, to determine the probability and the main cause of the incident, it is necessary to perform the system reliability modeling. In this paper, the reliability modeling of the Primary Cooling System in the research reactor RSG-GAS were done by using Fault Tree Analysis Method. This method is the most widespread method used to calculate the probability and investigate the critical components that cause the system failure. From the analysis results, it was get the occurrence probability of the event of 5.57 E-4. Basic events of Electric Power Trip and Blockage in the Heat Exchanger channel are the potential cause of the incident. (author)