Effect of Potential Energy Stored in Reactor Facility Coolant on NPP Safety and Economic Parameters

Abstract

Potential (non-nuclear) energy stored in reactor facility coolant is a crucial factor determining the NPP safety/hazard characteristics as it is inherent property of the material and cannot be changed. Enhancing safety of the NPP with traditional type reactor facilities, in which potential energy is stored in large quantities, requires buildup of the number of safety systems and in-depth defense barriers, which reduce the probability of severe accidents (but do not exclude the opportunity of their realization) and seriousness of their consequences. Keeping the risk of radioactivity release for different type reactor facilities at a same level of social acceptability, the number of safety systems and in-depth defense barriers, which determine essentially the NPP economical parameters, can be reduced with diminishing the potential energy stored in the reactor facility. To analyze the effect of potential energy on reactor facility safety/hazard, a diagram of reactor facility hazard has been proposed. It presents a probability of radioactivity release as a function of radioactivity release values for reactor facilities with identical radiation potential, which differ by values of potential energy stored in coolant. It is proposed to account NPP safety/hazard effect on economics by adding a certain interest on the electricity cost for making payments in a special insurance fund assigned to compensate the expenses for elimination of consequences of a possible accident.