On-line method to identify control rod drops in Pressurized Water Reactors

• On-line method to identify control rod drops in PWR reactors.
• Identification method based on the readings of the ex-core detector.
• Recognition of the patterns in the ex-core detector responses.

A control rod drop event in PWR reactors leads to an unsafe operating condition. It is important to quickly identify the rod to minimise undesirable effects in such a scenario. The goal of this work is to develop an online method to identify control rod drops in PWR reactors. The method entails the construction of a tool based on ex-core detector responses. It proposes to recognize patterns in the neutron ex-core detectors responses and thus to make an online identification of a control rod drop in the core during the reactor operation. The results of the study, as well as the behaviour of the detector responses demonstrated the feasibility of this method.