Validation of SCALE4.4a for Calculation of Xe – Sm Transients After a Scram of the BR2 Reactor

Aim of this report is to validate the computational modules system SCALE4.4a for evaluation of reactivity changes, macroscopic absorption cross sections and calculations of the positions of the Control Rods during their motion in Xe – Sm transient after a scram of the BR2 reactor. The rapid shutting down of the reactor by inserting of negative reactivity by the Control Rods is known as a reactor scram. Following reactor scram, a large xenon and samarium buildup occur in the reactor, which may appreciably affect the multiplication factor of the core due to enormous neutron absorption. The validation of the calculations of Xe – Sm transients by SCALE4.4a has been performed on the measurements of the positions of the Control Rods during their motion in Xe – Sm transients of the BR2 reactor and on comparison with the calculations by the standard procedure XESM, developed at the BR2 reactor. A final conclusion is made that the SCALE4.4a modules system can be used for evaluation of Xe – Sm transients of the BR2 reactor. The utilization of the code is simple, the computational time takes from few seconds.