Optimization Study of Improving Cavity Injection and Cooling System Performance

The optimization study is carried out for the disadvantage of cavity injection and cooling system（CIS） in HUALONG 1 plant, when dealing with serious accidents, and the new system configuration and operation of CIS is presented, including adopting control valves to control flow of different conditions, designing new cavity injection pumps, using Flowmaster software to model and calculate the system, to fix the main equipment parameters and verify the new system CIS satisfying the requirement of flow of serious accidents. Finally the problem of adopting low voltage SBO（station black-out） power for cavity injection pumps is solved, the rate of utilization of passive injection is increased, the CIS ability of dealing with various serious accidents is enhanced,to lay a solid foundation for improving cavity injection and cooling system in subsequent generationⅢ pressurized water reactor, which has great significance for the reliable operation of nuclear power plants.