Determining the Impact of Alpha-Particle-Emitting Contamination From the Fukushima-Daiichi Disaster on Japanese Semiconductor Manufacturing Sites

We briefly review nuclear reactor operation from the point of view of the major radioactive contaminants formed and consider how these were released and dispersed into the air, water, and soil around Fukushima. The risk of contamination from alpha-particle-emitting uranium and plutonium isotopes at semiconductor manufacturing sites in Japan is considered from theoretical aspects. We report the results of low background alpha-particle-emission measurements from wafers that were exposed to the air during and several weeks after the disaster, conclusively demonstrating that no detectable levels of alpha-emitting impurities from the Fukushima Daiichi disaster were found at either of the two manufacturing facilities.