International Conference Nuclear Energy for New Europe 2004 Nuclear Energy for New Europe 2004 Nuclear Energy for New Europe 2004 Nuclear Energy for New Europe 2004 Portorož • Slovenia • September 6-9 port2004@ijs.si www.drustvo-js.si/port2004 +386 1 588 5247, fax +386 1 561 2276 PORT2004, Nuclear Society of Slovenia, Jamova 39, SI-1000 Ljubljana, Slovenia 107.1 RELAP5 Calculations for Loss of Cooling Test at Romanian TRIGA 14 MW Research Reactor Mirea Mladin Institute for Nuclear Research, Pitesti, Romania mirea_mladin@easynet.ro ABSTRACT During Romanian TRIGA 14 MW steady state reactor commissioning in 1979 and beginning of 1980 a series of tests were performed to check the functioning of reactor systems and the response of the reactor core to transient initiators. Two of these tests consisted in inducing total forced cooling loss and also loss of primary pumps cooling with emergency pump in operation for 15 minutes after the event. Maximum fuel temperatures in hot pins were recorded. A RELAP5 reactor model was created to simulate the Loss of Coolant Transients and to compare with experiment. The scope of the paper is to describe the model and the most significant parameters which affect the results and to compare RELAP5 fuel temperature with that observed during the experiment in the hottest TRIGA fuel element. 1 INTRODUCTION There are two independent cores sharing the same pool: a high-flux 14 MW steady state reactor (SSR), research and materials testing reactor and an independent (from operational point of view) annular core pulsing reactor (ACPR). Figure 1 shows a view from above with the pool, the two reactor cores thermal column and beam tubes. The steady state reactor is a forced convection reactor cooled via a primary circuit containing 4 pumps and 3 heat exchangers. Secondary circuit has 3 pumps and cooling towers. At nominal power level 2 primary pumps are in operation. The reactor has an emergency (shutdown) pump located in the pool and operating through a pipe connected to the lower fitting of the reactor core. It is designed to remove decay heat and operates both simultaneously with primary pump(s) at selected power level and two hours after reactor shutdown. Emergency pump has redundant DC power supply. The ACPR is natural convection cooled by the pool water