An optically reconfigurable gate array VLSI driven by an unstabilized power supply unit

To execute decommissioning operations at nuclear power plants after certain accidents such as a melt-down, for instance, at the Fukushima Daiichi nuclear power plant, radiation-hardened very large scale integrations (VLSIs) are necessary as components for decommissioning robots and measurement systems. Moreover, radiation-hardened stabilized power supply units must be used to drive such electrical systems which include VLSIs. Unfortunately, the radiation-tolerance of commercially available stabilized power supply units is invariably low, less than 1 kGy, whereas the radiation intensity at the Fukushima Daiichi nuclear power plant site is estimated as higher than 1000 Sv/h. The lifetime of commercially available stabilized power supply units is less than 1 hr, which is always shorter than the lifetime of VLSIs. This paper therefore presents a proposal for a method of using VLSIs which use no stabilized power supply unit along with experiment results obtained using a radiation-hardened optically reconfigurable gate array.