HARDWARE RESILIENCE: A WAY TO ACHIEVE RELIABILITY AND SAFETY IN NEW NUCLEAR REACTORS I&C SYSTEMS

The idea that systems have a property called ‘resilience’ has emerged in the last decade [1]. In this paper we intend to bring the idea of resilient systems for the hardware applied in safety-critical systems, such as the new nuclear reactor instrumentation and control (I&C) systems. The new systems (based in hardware description language (HDL) programmable devices) have been developed in response to the obsolescence of old analog technologies and current microprocessor-based digital technologies. Although HDL programmable devices have been widely used in various other industries for decades, they are still very new in nuclear reactors systems, which can be seen as a challenge and risk in the safety analyses and licensing efforts for utilities and designers. The goal of this work is to develop and test hardware architectures to tolerate the occurrence of faults, including multiple faults, minimizing the impact of the recovery process on system availability. Basic concepts of resilience in complex systems, as “return to equilibrium”, “robustness” and “extra adaptive capacity” were analyzed from the point of view of hardware architectures, leading to linkages between concepts and methods for resilience using an approach that increases reliability and simplifies the licensing process of systems based in HDL programmable devices in nuclear plants.