Comparison and Analysis of Residual Heat Removal Systems of Reactors in Station Blackout Accidents

Abstract

A comparative analysis is performed of emergency cool-down systems of water-cooled reactors, using passive heat-removal systems. The use of such a system reduces the likelihood of serious accidents with core damage at NPP but the capital investment and associated operating costs are higher. Auxiliary expenditures on maintaining this system in a standby mode are also required. A scheme combining active and passive cool-down systems is proposed owing to the rejection of air heat-exchangers-condensers of the passive heat-removal system and the installation of an auxiliary low-capacity steam turbogenerator is proposed. A comparative technical-economic analysis of the proposed combined cool-down system and an air passive heat-removal system is performed. The calculations show that at comparable safety levels such a system makes it possible to reduce capital and total operating expenses for NPP located in all climatic belts.