Ishchenko O. "The spent fuel exploitation systems modernization to guarantee the ecceptable point of the technical temperatures in the spent fuel pool in the emergency situations"

The thesis is devoted to the solution of the actual scientific and technical problem of guaranteeing the acceptable point of the technical temperatures in the spent fuel pool cooling system in the emergency situations due to the modernization of the spent nuclear fuel exploitation systems based on the developed method of modernization of these systems with using the mathematical and physical modeling. The analysis of the initial events leading to the outflow of the coolant of the first circuit and an increase in the temperature in the containment is performed. The analysis of the operability of the spent fuel pool cooling systems during full de-energization is performed to determine the acceptable parameters in the spent fuel cooling and storage systems. The mathematical model of auxiliary systems for modeling processes in the spent fuel cooling and storage systems is developed. A computational experiment which is based on a mathematical model in the spent fuel cooling and storage systems as well as pressure compensation system of the primary circuit was done. The parameters of the determining characteristics of these systems that provide acceptable technological temperatures in emergency situations are determined. The physical experiment in order to study properties of the spent fuel cooling systems and pressure compensation was conducted. The degree of error of the results of computational experiments which are determined the reliability of the obtained results is determined. The development of the method for upgrading the structures of auxiliary equipment for an additional cooling system for the coolant in the spent fuel pool was done. Key words: initial events, spent nuclear fuel, method of modernization, mathematical modeling, physical modeling, hydraulic shock.