The simplified P3 approach on a trigonal geometry in the nodal reactor code DYN3D
21st Symposium of AER on VVER Reactor Physics and Reactor Safety (2011, Dresden, Germany)
Reactor physics experiments and code validation
Abstract
DYN3D is a three-dimensional nodal di?usion code for steady-state and transient analyses
of Light-Water Reactors (LWRs) with square and hexagonal fuel assembly geometries.
Currently, several versions of the DYN3D code are available including a multi-group
di?usion and a simpli?ed P3 (SP3 ) neutron transport option.
In this work, the multi-group SP3 method based on trigonal-z geometry was developed.
The method is applicable to the analysis of reactor cores with hexagonal fuel assemblies
and allows ?exible mesh re?nement, which is of particular importance for VVER-type
Pressurized Water Reactors (PWRs) as well as for innovative reactor concepts including
block type High-Temperature Reactors (HTRs) and Sodium Fast Reactors (SFRs).
In this paper, the theoretical background for the trigonal SP3 methodology is outlined and
the results of a preliminary veri?cation analysis are presented by means of a simpli?ed
VVER-440 core test example. The accordant cross sections and reference solutions were
produced by the Monte Carlo code SERPENT. The DYN3D results are in good agreement
with the reference solutions. The average deviation in the nodal power distribution is
about 1%.