Neutronic library for VVER-440 calculations by DYN3D - initial version
25th Symposium of AER on VVER Reactor Physics and Reactor Safety (2015, Balatongyörök, Hungary)
Advances in spectral and core calculation methods
Preparation of first files at interpolation cross section library of dynamic macrocode DYN3D,
suitable for VVER-440 calculations, is described at this paper. Spectral code HELIOS was
used for very first library files preparation. Mochovce NPP first fuel cycle calculations were
used for comparison with standard BIPR7 code results. Good functionality of first library
version was concluded.
Dynamic macrocode DYN3D-MG is used widely for VVER-440 calculations. Its
performance can be improved by suitable cross section library that enables accurate enough
burnup calculations and is needed for core and reactor analyses. Cross section interpolation
tables were selected for this task performance.
Spectral code HELIOS is used regularly for preparation of LWR cross section libraries for
DYN3D-MG and other macrocodes. Preparation of cross section data sets for VVER-440
reactor and its transformation into cross section library by developed library code is described
at this report.
2. TARGET LIBRARY FORMAT
Dynamic macrocode DYN3D-MG contains various possibilities for cross section input.
Choice ?IWQS = 22? was selected as alternative for VVER-440 burnup calculations 1.
This type of library is characterised by multi-dimensional tables of data records, in which all
possible combinations of parameter variation are considered. The accuracy of this method
increases with the density of ?data points?, calculated by the cell-code calculations. To avoid
huge tables and consequently immense computing times it make sense to choose the datapoint density in a way that matches the accuracy of both cell code and diffusion code
(DYN3D at this case).
Spectral code HELIOS was selected for generation of multi-dimensional-table library 2. It is
used at DYN3D-MG with linear multi-dimensional interpolation. In general, five
?dimensions? = operation parameters are used as follows:
? Coolant density D
? Boron concentration Cb
? Fuel temperature Tf
? Coolant temperature Tm