Abstract
The FPGA (field programmable gate array) is a digital device widely used in various fields of industry. FPGAs can be used to perform functions that are safety critical and require high reliability, like in automobiles, aircraft control and assistance and mission-critical applications in the aerospace industry. With these merits, FPGAs are receiving increased attention worldwide for application in nuclear plant instrumentation and control (I&C) systems, mainly for Reactor Protection System (RPS).
Reasons for this include the fact that conventional analog electronics technologies are become obsolete. I&C systems of new Reactors have been designed to adopt the digital equipment such as PLC (Programmable Logic Controller) and DCS (Distributed Control System). But microprocessors-based systems may not be simply qualified because of its complex characteristics. For example, microprocessor cores execute one instruction at a time, and an operating system is needed to manage the execution of programs. As a result, nuclear power plant operators and I&C suppliers may consider other non-computer-based digital technologies, such as devices that may be configured using HDL (Hardware Description Language).
FPGAs, commonly referred to as HDL programmable devices (HPDs), can run without an operating system and the design architecture is inherently parallel. Despite the attractive features, the use of such programmable devices in safety critical systems for nuclear power plants is relatively new in many countries, and the regulatory approach to licensing such devices may not be clear.
In this paper we aim to assess advantages and the limitations on FPGA-based solutions, considering the design guidelines and regulations on the use of FPGAs in Nuclear Plant I&C Systems. We will also examine some circuit design techniques in FPGA to help mitigate failures and provide resilience. The objective is to show how FPGA-based systems can provide cost-effective options for I&C systems in modernization projects, ensuring safe and reliable operation, meeting licensing requirements, such as separation, redundancy and diversity.
