Improvements to hydrogen depleting and monitoring system for Chinese Pressurized Reactor 1000

We evaluate the hydrogen depletion ability of the hydrogen depletion system for Chinese Pressurized Reactor 1000 (CPR1000), which has been applied in nuclear power plants with pressurized water reactors; moreover, we introduce a new device that can continuously monitor hydrogen concentration inside the CPR1000 containment building. Experimental studies show that a moveable hydrogen autocatalytic recombiner alone can sufficiently deplete hydrogen under the condition of a design-basis accident, and 33 passive autocatalytic recombiners placed in the areas of high hydrogen concentration satisfy the hydrogen depletion requirements under the condition of a beyond-design-basis accident. Meanwhile, the hydrogen concentration monitoring system is designed and installed based on the approach of detecting the temperature increase caused by the catalytic reaction of hydrogen. In conclusion, the hydrogen depletion capacity of the CPR1000 meets the requirements, and the system's safety can be enhanced by the improved hydrogen concentration monitoring system.