2012

Ranta, Jukka

Field programmable gate arrays are a form of programmable electronic device used in various applications including automation systems. In recent years, there has been a growing interest in the use of FPGA-based systems also for safety automation of nuclear power plants. The interest is driven by the need for reliable new alternatives to replace, on one hand, the aging technology currently in use and, on the other hand, microprocessor and software-based systems, which are seen as overly complex from the safety evaluation point of view. This report presents an overview of FPGA technology, including hardware aspects, the application development process, risks and advantages of the technology, and introduces some of the current systems. FPGAs contain an interesting combination of features from software-based and fully hardware-based systems. Application development has a great deal in common with software development, but the final product is a hardware component without the operating system and other platform functions on which software would execute. Currently the number of FPGA-based applications used for safety functions of nuclear power plants is rather limited, but it is growing. So far there is little experience or common solid understanding between different parties on how FPGAs should be evaluated and handled in the licensing process.