VERIFICATION OF THE TRIGONAL GEOMETRY DIFFUSION AND SP3 MODELS OF THE CODE DYN3D
22nd Symposium of AER on VVER Reactor Physics and Reactor Safety (2012, Průhonice, Czech Republic)
Advances in spectral and core calculation methods
Abstract
DYN3D is a three-dimensional nodal di?usion code for steady-state and transient analyses
of Light-Water Reactors with square and hexagonal fuel assembly geometries, applicable
also to innovative reactor concepts. Currently, several versions of the DYN3D code are
available including a multi-group di?usion and simpli?ed P3 (SP3 ) neutron transport
option.
In this work, both the di?usion and SP3 method in trigonal geometry are veri?ed by
means of ?ne-mesh homogenized reference solutions. Good agreement is observed for
eigenvalues, neutron ?ux and power distributions. Mesh re?nement studies show that the
trigonal nodal DYN3D methods converge well to the ?ne-mesh references. Furthermore,
an anisotropic-scattering benchmark problem was chosen to show the advantage of the
SP3 method over the di?usion approach.
1 INTRODUCTION
The reactor dynamics code DYN3D is a three-dimensional best-estimate tool for simulating steady states and transients of Light-Water Reactors (LWRs), which has been
developed at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Germany.? It comprises
a three-dimensional neutron-kinetics model based on nodal expansion methods, a thermalhydraulics core module with one- and two-phase coolant ?ow analysis capabilities, and a
fuel-rod model [1, 2]. Also burnup and poison-dynamics calculations can be performed
with DYN3D.
?