Recently, field programmable gate arrays (FPGAs) are anticipated for use in high-radiation environments such as the Fukushima Daiichi nuclear power plant. According to recent news, regions with 650 Sv/h radiation have been found at the Fukushima Daiichi nuclear power plant. Under such extremely high radiation environments, high-speed scrubbing operations must be used to maintain correct circuit information on the configuration memory of programmable gate arrays. Up to now, optical high-speed scrubbing based on an optically reconfigurable gate array has been proposed. This paper presents a demonstration of the radiation tolerance of the optical high-speed scrubbing based on an optically reconfigurable gate array VLSI by using lasers that emulate strong radiation environments. It has been confirmed that 70-ns period high-speed scrubbing operations on the optically reconfigurable gate array are never disturbed by the emulated radiation.