Lessons Learned: Low Condenser Vacuum/High Condensate Dissolved Oxygen Levels at D. C. Cook Nuclear Power Plant

During the summer of 2002, the main condenser vacuum started degrading at both Units 1 and 2 of the D. C. Cook Nuclear Power Plant. An evaluation of the high condensate dissolved oxygen levels that were being experienced at Unit 1 indicated performance degradation of the steam jet air ejector system. This paper describes the lessons learned from detailed analysis, inspection and evaluation of the design, performance and operation of the steam jet air ejector systems for both units of the D. C. Cook Nuclear Power Plant. Various corrective actions undertaken as well as proposed for future implementation are discussed and recommendations are provided for proper design, performance, operation and maintenance of the steam jet air ejector systems.