CALCULATIONS OF NEUTRON AND THERMO PHYSICAL CHARACTERISTICS FOR GENERATION IV REACTOR “VVER-SKD”
22nd Symposium of AER on VVER Reactor Physics and Reactor Safety (2012, Průhonice, Czech Republic)
NEW REACTOR CONCEPT
Abstract
The calculated assessment of the main neutron and thermo-physical characteristics of
VVER reactor with supercritical coolant pressure using the upgraded version of code package
SAPFIR&95RC has been performed. Calculation model of the VVER-SCP core is developed.
The version under consideration has a single-circuit coolant circulation system, heat up
amounts to more than 2500C, the power unit efficiency is more than 40 %.
Two versions of the reactor core lay-out were considered ? with a single-pass coolant
flow scheme and a two-pass coolant scheme. The design of standard VVER forms the basis of
VVER-SCP reactor core. There are differences ? fuel rod lattice is more tight, diameter of a
fuel rod is increased, jacketed FA is applied, MOX-fuel (mixture of the weapon-grade
plutonium and regenerated plutonium) is used.
The calculated analysis of maximum temperature of fuel, cladding, coolant, maximum
heat flux of a fuel rod and length of fuel cycle is carried out. Various versions of pressure
losses of throttling washers are considered.
VVER-SCP two-pass coolant core is divided into two parts of coolant flow with
approximately equal number of FA, they are a downcomer and a riser section. Such a
structure of the core will enable to decrease considerably a volumetric power peaking factor.
Fuel rod design and fuel matrix in the downcomer and riser section are similar.
The obtained neutron and thermo-physical characteristics of the core for a two-pass
coolant scheme (temperature of fuel, cladding, volumetric power peaking factor, maximum
linear heat flux of a fuel rod) are lower than in a single-pass coolant version. However, in
two-pass coolant scheme, coolant temperature coefficient of reactivity becomes positive in the
course of the fuel cycle unlike a single-pass coolant scheme. At the same time, a two-pass
coolant scheme does not realize the majority of the optimized solutions that have already been
used in a single-pass coolant scheme ? additional calculated analyses are needed to conduct
aimed at optimization of the core design.