Validation of new 3-D neutronics model in APROS for hexagonal geometry
20th Symposium of AER on VVER Reactor Physics and Reactor Safety (2010, Hanasaari, Espoo, Finland)
Reactor dynamics and safety analysis
Abstract
APROS – Advanced PROcess Simulation environment ? is a widely used simulation tool for
nuclear power plant modelling. Earlier the three-dimensional neutronics calculation has been
based on model using the difference method. The original three-dimensional core model is
mainly used in power plant simulator applications, where it fits well because of its speed. For
safety analysis purposes, however, a new model was considered to be an important
improvement to meet the accuracy requirements. A sophisticated nodal model used already in
HEXTRAN and TRAB-3D was decided to be implemented into APROS. The hexagonal part
of the model has now been implemented and tested. For practical reasons, the model was
programmed from scratch into APROS and also some small improvements were added and
thus, an extensive validation program was necessary to prove the correct behaviour of the
model. In this paper, the most important results from AER kinetic benchmarks 2 & 3
calculations are shown as well as the calculation results against data achieved LR-0 test
reactor space-time kinetic experiments. Since the model is similar to the one in HEXTRAN,
the results in benchmarks are compared to the results by it. In LR-0 calculations, results by
both, original and new model are presented and compared to the measurements. The results
shows that the implementation of the model has been successful and the new model improves
the accuracy of three-dimensional neutronics calculation in APROS into the level required in
safety analyses.