Concepts of Passive, Light Water Pressure-Tube Reactors

Abstract

High-power-rating, (>1000MWe) passive pressure tube light water-cooled reactors are described that have the ability to reliably discharge decay heat to the ultimate heat sink, without the need to replenish primary coolant in loss of coolant accidents, while ensuring the integrity of the fuel and reusability of major reactor components. It is shown that pressure tube reactors have the attractive potential to dissipate (he decay heat from voided fuel elements of large-power-rating cores without exceeding safe temperature limits. Two basic versions of a pressure tube, light water cooled and moderated reactor-the dry calandria and wet calandria concepts-are proposed and their advantages and limitations are pointed out.