Deciphering the measured ratios of Iodine-131 to Cesium-137 at the Fukushima reactors

Abstract

We calculate the relative abundance of the radioactive isotopes Iodine-131 and Cesium-137 produced by nuclear fission in reactors and compare it with data taken at the troubled Fukushima Dai-ichi nuclear power plant. The ratio of radioactivities of these two isotopes can be used to obtain information about when the nuclear reactions terminated.

Comments: 12 pages, 6 figures. Updated version of the article with the same title uploaded on this arXiv on May 2, 2011; To appear in Progress of Theoretical Physics 126