Coolant Chemistry Characteristics During Safety Demonstration Test Using HTTR

摘要

The HTTR is the first high-temperature gas-cooled reactor (HTGR) in Japan with thermal power of 30MW and 950℃ maximum reactor-outlet coolant temperature. In HTGRs, in order to avoid the oxidation of graphite using at the core structures and the corrosion of high-temperature material using at the heat exchanger, it is important to control and monitor the coolant chemistry during any reactor operation especially temperature transients. In the coolant flow reduction test, which is one of the safety demonstration tests, temperature is changed rapidly by stopping of gas circulators. The potential of carbon deposition was evaluated using the measured impurity concentration during the temperature transients.