Radiation-hardened stabilized power supply unit based on bipolar transistors

For work to decommission melted reactors in nuclear power plants after an accident, a radiation-hardened stabilized power supply unit is demanded for use with any system. However, currently available stabilized power supply units is invariably vulnerable to radiation. The radiation tolerance is always less than 1 kGy. Since the radiation intensity in the Fukushima Daiichi nuclear power plant is estimated as greater than 1000 Sv/h, the expected lifetime of power supply units is therefore limited to less than one hour. This paper presents a new design for radiation-hardened stabilized power supply units. The power supply units never use field effect transistors: they only use bipolar transistors. The experimentally assessed power supply unit has achieved 2 MGy total-ionizing dose tolerance, which is sufficiently higher than currently available radiation-hardened power supply units.