%0 Journal Article
%T Analysis of Loss of Flow Events on Brazilian Multipurpose Reactor Using the Relap5 Code
%A Humberto V. Soares
%A Ivan D. Aronne
%A Antonella L. Costa
%A Claubia Pereira
%A Maria Auxiliadora F. Veloso
%J International Journal of Nuclear Energy
%D 2014
%R 10.1155/2014/186189
%X This work presents the thermal hydraulic simulation of the Brazilian multipurpose reactor (RMB) using a RELAP5/MOD3.3 model. Beyond steady state calculations, three transient cases of loss of flow accident (LOFA) in the primary cooling system have been simulated. The RELAP5 simulations demonstrate that after all initiating events, the reactor reaches a safe new steady state keeping the integrity and safety of the core. Moreover, a sensitivity study was performed to verify the nodalization behavior due to the variation of the thermal hydraulic channels in the reactor core. Transient calculations demonstrate that both nodalizations follow approximately the same behavior. 1. Introduction The Brazilian Nuclear Energy Commission (Comiss£¿o Nacional de Energia Nuclear¡ªCNEN) is leading the project of the Brazilian Multipurpose Reactor (RMB) envisaged to be projected, constructed, and operated to attend the present Brazilian need for a multipurpose neutron source, which will be able to supply the demand of radioisotopes, carry out material tests, and develop scientific, commercial, and medical applications with the use of neutron beams. The RMB will have three main functions: radioisotope production (mainly molybdenum), fuel, and material irradiation testing to support the Brazilian nuclear energy program. Moreover, it will provide neutron beams for scientific and applied research. Among the different types of research nuclear reactors, the open pool reactors are the most common and the most used, because of their great versatility, easy operation, and safety. The reactors Osiris in France, and mainly the Australian research reactor OPAL (Open Pool Australian Lightwater Reactor) projected by Argentina and built in Australia are being used as initial references for the RMB project. In the present work, a nodalization for the RMB core using the RELAP5/MOD3.3 and the most important components of the pool loop and core loop circuits are presented. Loss of flow accidents have been performed for two types of nodalization changing the number of core thermal hydraulic channels to verify the sensitivity study. 1.1. The Use of RELAP5 for Research Reactors Simulation The thermal hydraulic system code RELAP5 has been developed to best estimate transient simulation of light water power reactor systems during postulated accidents. Recent works have demonstrated that the code can be also used with good predictions for thermal hydraulic analysis of research reactors as it can be verified in the present literature [1¨C8]. Most of the research reactors operate at low-pressure
%U http://www.hindawi.com/journals/ijne/2014/186189/