Fukushima Daiichi nuclear disaster casualties of radioactivity released into the atmosphere was approximately one-tenth as much as was released during the Chernobyl disaster. Significant amounts of radioactive material have also been released into ground and ocean waters. Measurements taken by the Japanese government 30–50 km from the plant showed caesium-137 levels high enough to cause concern, leading the government to ban the sale of food grown in the area. Tokyo officials temporarily recommended that tap water should not be used to prepare food for infants. In May 2012, TEPCO reported that at least 900 PBq had been released "into the atmosphere in March, 2011 alone."
Caesium chloride container which is then enclosed into another steel casing. The sealing is required to protect the salt from moisture. In the laboratory, CsCl can be obtained by treating caesium hydroxide, carbonate, caesium bicarbonate, or caesium sulfide with hydrochloric acid: Caesium chloride is the main precursor to caesium metal by high temperature reduction: A similar reaction – heating CsCl with calcium in vacuum in presence of phosphorus – was first reported in 1905 by the French chemist M. L. Hackspill and is still used industrially. Caesium hydroxide is obtained by electrolysis of aqueous caesium chloride solution: Caesium chloride is widely used