The Use of Burnable Poisons in VVER-type Reactors to Reduce the Fraction of the Reactivity Margin Compensated by the Liquid System During Extended Runs

Abstract

The paper presents the results of a computational and theoretical analysis of the use of various burnable poisons placed in a fuel rod for the maximum reduction in the reactivity margin compensated by a liquid system based on a boron absorber for VVER-type reactors operating in extended campaigns. Various layouts of fuel rods placement in fuel assemblies and with different concentrations of burnable poisons are considered, which are considered natural gadolinium and erbium. The analysis is carried out using simplified models of fuel burnup at partial refueling.

Keywords

• выгорающий поглотитель
• полиячейка
• ввэр
• коэффициент размножения
• избыточная реактивность
• гадолиний
• твэл
• эрбий
• борное регулирование