Calculation of Isotope Burn-up and Change in Efficiency of Absorbing Elements of VVER-1000 Control and Protection System during Burn-up
16th Symposium of AER on VVER Reactor Physics and Reactor Safety (2006, Bratislava, Slovakia)
Spectral and Core Calculations
Abstract
The report deals with fast and thermal neutron flows distribution in structural elements of VVER-1000 fuel assembly and absorbing rods, determination of absorbing isotope burn-up and worth variation in VVER reactor control and protection system rods.
Simulation of absorber rod burn-up is provided using code package SAPPHIRE_95&RC_VVER allowing detailed description of the core segment spatial model.
Maximum burn-up of absorbing rods and respective worth variation of control and protection system rods is determined on the basis of a number of calculations considering known characteristics of fuel cycles.