Uses of radiation for development and welfare

The economic scale of radiation application in the major fields, such as industry, medical care, and agriculture is comparable to that of nuclear power in Japan and in USA where 53 and 103 nuclear power plants are in operation, respectively. The major tool of radiation application for industry and health care is electron accelerator of which reliability has been much improved in the past 3 decades. There are about 13000 accelerators installed worldwide, of which 1200 are used for industrial applications. The upgrading of polymers by the radiation cross-linking and grafting by electron beams is extensively used for the production of high quality automobile tires, heat resistant wires and heat shrinkable materials and others. The growing applications of electron accelerator are sterilization of medical products and food packaging as well as cleaning exhaust gases and wastes water for environmental protection. The functional polymers such as battery separators, deodorant fibers, and wound dressing hydrogel are effectively produced by the use of electron accelerators. Very low energy electron accelerator of 20-200keV is used for curing of surface coating without emission of organic solvent. Ion accelerators are widely used for the ion-implantation for semiconductor production and surface modification. More than 1000 ion accelerators are used in Japan for these applications. The world first medical ion accelerator in Japan has proven with more than 2,000 clinical test that it can provide highly effective radio-therapy of cancer. The synchrotron orbital radiation is used for material research. New accelerators based spallation neutron sources are under construction in Japan, USA and Europe (UK) for basic sciences and technology. They produce extremely high flux neutron in pulsed mode which is not available from reactor-based source. Accelerator is an effective tool for nanotechnology. (author)