Addressing the Issues of Operation Safety and Reusability of Nuclear Reactor I&C Systems through FPGA Designs

Abstract

This paper describes the use of Field Programmable Gate Arrays (FPGAs) devices in Nuclear Reactors Instruments. The design, simulation, implementation and test of two examples are included. The first is a reactor control rod position sensing electronic unit intended as a replacement of the outdated Russian type in old power reactors. The second is a design to implement the Trip Unit of a Reactor Protection System (RPS) using an FPGA. Instead of the traditional embedded Microprocessor based interface design method, a tailor-made FPGA based circuit is built to substitute the Trip Unit (TU) existing in research reactors. The RPS is responsible for the initiation signals that trigger the protective actions in case of anticipated operational occurrences or accident conditions during the operational modes of the reactor. The proposed designed circuit replaces the Single Board Computer which have the embedded S/W program of the TU providing the same integrated H/W & S/W functions implemented in FPGA Chip housed in a printed circuit board, which uses the same specifications of existing system bus (STD32 bus). FPGA implementation of both TU and STD32 Bus as well as position sensing unit in VHDL can address the issues of operation safety and system components reusability.