Abstract: The paper focuses on the performance of reflector trap passive safety system incorporated in the GFR 2400 reactor design. Multiple studies are raising question about the technical feasibility of the GFR 2400 concept, thus the new neutron trap passive system is introduced in the paper to cope with abnormal operation of this reactor. The coupled calculation scheme is used in the paper, where NESTLE code is used for coupled steady state and transient simulations of the reactor performance. The NESTLE code system solves multi-group transient diffusion equation utilizing nodal expansion method and is internally coupled with thermal-hydraulic sub-channel code. The SCALE6 software package is used for processing of macroscopic multi-group cross-sections that are used in the NESTLE code. The performance of the neutron trap passive system is simulated by the developed model for typical abnormal transients, such as control rod withdrawal or primary blower shutdown during the full power operation. Curie point latch acts as the actuation mechanism of the passive system. Temperature distributions are studied and the applicability of the neutron trap passive safety system is discussed in the paper.
Keyword: GFR 2400, passive system, neutron trap, coupled calculation, transient calculation, NESTLE
