The influence of the small radial FAs displacements on the power distribution in the VVER-cores
21st Symposium of AER on VVER Reactor Physics and Reactor Safety (2011, Dresden, Germany)
Spectral and core calculations
Abstract
VVER core is located inside a metal core basket. There is a possibility of the some
FAs displacements within a basket in the transverse direction in the design tolerances, as a
result of assembly bending or during mounting of the core. We have investigated several
different variants of changes in the gap size between fuel assemblies for a fresh state of the
core at the hot zero power level, including the core displacement entirely within the core
basket. The calculations were performed by MCU (Monte-Carlo code) for the full threedimensional reactor core model. It is shown that even small displacements can lead to
significant distortions of the power distribution.