Preliminary results of the seventh three-dimensional AER dynamic benchmark problem calculation. Solution of problem with DYN3D- and RELAP5-3D-codes
21st Symposium of AER on VVER Reactor Physics and Reactor Safety (2011, Dresden, Germany)
Reactor dynamics and safety analysis
Abstract
The paper gives a brief survey of the 7th three-dimensional AER dynamic benchmark
calculation results received with the codes DYN3D and RELAP5-3D at NRI e?. This
benchmark was defined at the 20th AER Symposium in Hanassari (Finland). It is focused on
investigation of transient behaviour in a VVER-440 nuclear power plant. Its initiating event is
opening of the main isolation valve and re-connection of the loop with its main circulation
pump in operation. The VVER-440 plant is at the end of the first fuel cycle and in hot full
power conditions. Stationary and burnup calculations were performed with the code DYN3D.
Transient calculation was made with the system code RELAP5-3D . The two-group
homogenized cross sections library HELGD05 created by HELIOS code was used for the
generation of reactor core neutronic parameters. The detailed six loops model of NPP
Dukovany was adopted for the 7th AER dynamic benchmark purposes. The RELAP5-3D full
core neutronic model was coupled with 49 core thermal-hydraulic channels and 8 reflector
channels connected with the three-dimensional model of the reactor vessel. The detailed
nodalization of reactor downcomer, lower and upper plenum was used. Mixing in lower and
upper plenum was simulated. The first part of paper contains a brief characteristic of
RELAP5-3D system code and a short description of NPP input deck and reactor core model.
The second part shows the time dependencies of important global and local parameters.