Timeline of the Fukushima Daiichi nuclear disaster pumps could be retrofitted to deliver concrete for that purpose. Prior to the elevation to level 7 by the Japanese authorities James Acton, Associate of the Nuclear Policy Program at the Carnegie Endowment for International Peace, was of the opinion that "Fukushima is not the worst nuclear accident ever but it is the most complicated and the most dramatic, was a crisis that played out in real time on TV. Chernobyl did not." A survey of radiation in seawater outside unit 2 shows radioactive isotope concentrations (iodine-131, caesium-134 and caesium-137) falling for the third consecutive day since the leak was
Caesium inside old stars and by the R-process in supernova explosions. The only stable caesium isotope is Cs, with 78 neutrons. Although it has a large nuclear spin (+), nuclear magnetic resonance studies can use this isotope at a resonating frequency of 11.7 MHz. The radioactive Cs has a very long half-life of about 2.3 million years, longest of all radioactive isotopes of caesium. Cs and Cs have half-lives of 30 and two years, respectively. Cs decomposes to a short-lived Ba by beta decay, and then to nonradioactive barium, while Cs transforms into Ba directly. The isotopes with mass numbers of