Masahiro Yamamoto
University of Tokyo

Analyses For Inverse Problems Related To The Fukushima Daiichi Nuclear Disaster: An Application Of Mathematics

The Fukushima Daiichi Nuclear Disaster in March 2011 has released cesium-137 etc. into environments. The long-standing prediction of the diffusion is important and for it, the starting point is inverse problems of determining unknown physical parameters on the basis of model equations. Moreover some extrapolation procedure of measured data is a kind of inverse problems. I discuss the following three related inverse problems and present numerical results for field data as well as theoretical results such as the uniqueness and the stability:
• Determination of amplitude of explosion
• Diffusion of radioactive substances in the soil related to the decontamination of farm- lands and estimation of air dose rate of radioactive substances
• air dose rate of radioactive substances at the human height level by high-altitude data by drones The incident was very serious but the needed mathematical analysis is quite standard. I intend to demonstrate that the talk is a case study where mathematics is effective also for such serious real-world problems.