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
Period 6 element spectroscopy. The first small-scale applications for caesium have been as a "getter" in vacuum tubes and in photoelectric cells. In 1967, a specific frequency from the emission spectrum of caesium-133 was chosen to be used in the definition of the second by the International System of Units. Since then, caesium has been widely used in atomic clocks. Since the 1990s, the largest application of the element has been as caesium formate for drilling fluids. It has a range of applications in the production of electricity, in electronics, and in chemistry. The radioactive isotope caesium-137 has a half-life of about 30