AN ANALYSIS OF REACTIVITY PREDICTION DURING THE REACTOR START-UP PROCESS
24th Symposium of AER on VVER Reactor Physics and Reactor Safety (2014, Sochi, Russia)
Core surveillance and monitoring
Abstract
AN ANALYSIS OF REACTIVITY PREDICTION DURING THE REACTOR START-UP PROCESS
Josef Bajgl
CEZ Inc., Dukovany NPP
Václav Krýsl, Jiří Švarný ŠKODA JS, a.s.
Czech Republic
ABSTRACT
The different VVER-440 core fuel loadings subcriticality is performed during the start- up process by boron dilution or control assembly withdrawn by macrocode MOBY-DICK calculations. The dynamic reactivity and quasicritical reactivity are compared and sensitivity of reactivity prediction at the low boundary of start–up interval has been provided on the bases of different modelling of ionization chamber (IC) response calculation. Special attention is paid to the impact of power distribution and spontaneous fission distribution form factor on IC response correction during control assembly movement. Precision and robustness of different corrections of IC signal processing in real core start-up processed was validated.