Simulation of AER-7 benchmark with the coupled code DYN3D/ATHLET
21st Symposium of AER on VVER Reactor Physics and Reactor Safety (2011, Dresden, Germany)
Reactor dynamics and safety analysis
Abstract
The 7th dynamic benchmark is the most recent problem specified within the AER activities on
verification of the coupled neutronic/thermal-hydraulic codes. This is the VVER-440 transient
initiated by re-connection of the isolated reactor circulation loop filled with a low-temperature
coolant. During the transient a core power excursion with a non-symmetric radial distribution is
expected due to incomplete coolant mixing at the core inlet.
The externally coupled code system DYN3D/ATHLET developed in HZDR was used in the
benchmark simulation. In the case of external coupling all neutronic and thermal-hydraulic
parameters of the core are calculated by the 3D code of neutron kinetics DYN3D.
The computer model of the VVER-440 reactor used in the AER-7 calculations represents a
modified version of the earlier developed input deck for the AER-6 benchmark simulation. The
model includes 6 reactor loops with the main circulation pumps and steam generators. The
secondary system is modelled up to the turbine valves. The 3D core model includes all 349 fuel
assemblies (assembly-by-assembly approach).
The main results of the benchmark calculation are presented and discussed.