The Preliminary Analysis of the Loss of Primary Coolant Flow Test in the HTTR

Loss of primary coolant flow test is under planning by using the High Temperature engineering Test Reactor (HTTR). In this test, all the gas circulators are tripped and the position of all control rods keeps its initial one. The new calculation model was developed to perform the preliminary analysis for the test. This model is so improved that an equivalent fuel channel model based on one point kinetics code and a whole reactor model based on two-dimensional thermal analysis code are coupled to simulate the reactor performance during the loss of coolant flow. Both calculation codes were used in the safety evaluation of the HTTR licensing. The improved calculation model was validated by comparison between the calculated result and the experimental one obtained from the coolant flow reduction test in the HTTR. The loss of primary coolant flow test simulates the depressurization accident and the data obtained from the test is useful for the validation and improvement of the calculation code applied to the safety analysis in the future HTGR such as Very High Temperature Reactor which is selected as one of candidates of the generation IV reactor system.