Development and validation of the new coupled code system TRADYN

A new coupled code system TRADYN has been developed at the Institute for Neutron Physics and Reactor Technology (INR) of Karlsruhe Institute of Technology (KIT) to simulate Boiling Water Reactors (BWR) transients such as Anticipated Transients without Scram (ATWS). It was developed by integrating the neutron kinetic solver DYN3D multigroup version into the system code TRACE. First of all, the programming of different routines to control the sequence of execution of the solvers as well as to perform the data exchange between them was done. For this purpose, the General Interface (GI) in charge of the data transfer and synchronization between TRACE and PARCS was extended for the integration of DYN3D as an additional reactor dynamics code. The new system TRADYN offers to the user now the possibility to select either PARCS or DYN3D as reactor dynamics solver. Additionally, MED file can be automatically generated by TRADYN for post-processing using the NURESIM platform tools. In order to do the validation of TRADYN, the international “Boiling Water Reactor Turbine Trip (TT)” benchmark based on the BWR Peach-Bottom-2 was selected. A comparison of TRADYN simulations using both PARCS and DYN3D coupled to TRACE against plant data is performed. The obtained results have showed good agreement of the main parameters for both steady-state and transient conditions.