Modifications to Improve Reliability in Deaerator Level Control by Using Digital Technology

Abstract

As analog electronic components in nuclear power plants age, their reliability decreases. This poses challenges to operational and maintenance costs. Thanks to digital technology, new replacement micro-chip based devices can be used to address the obsolescence issue. The reliability of control systems can be further enhanced by adopting more defensive control logic, fault handling features and user-friendly controller interface based on human factors assessment. Deaerator level control system is one of the complex control loops in Pickering Nuclear Generation Station. The original controller was implemented using a number of analog devices which are now obsolete. Presented in this paper are several design techniques implemented to improve the reliability of the digital deaerator level controller.