Fukushima Daiichi nuclear disaster on the International Nuclear Event Scale (INES). This scale runs from 0, indicating an abnormal situation with no safety consequences, to 7, indicating an accident causing widespread contamination with serious health and environmental effects. Prior to Fukushima, the Chernobyl disaster was the only level 7 event on record, while the Three Mile Island accident was rated as level 5. A 2012 analysis of the intermediate and long-lived radioactivity released found about 10–20% of that released from the Chernobyl disaster. Approximately 15 PBq of caesium-137 was released, compared with approximately 85 PBq of caesium-137 at Chernobyl, indicating the release of of
On-Line Isotope Mass Separator more than 60 physics experiments are active there. Radioactive nuclei are produced at ISOLDE by impinging a high energy beam of protons on a stationary target. There are a number of target materials depending on the desired final species. Collisions between the proton beam and the target produce a variety of fragments, which are extracted and filtered to yield the desired isotope. The time required for extraction places a lower limit on the half life of isotopes which can be produced by this method. Once extracted, the isotopes are directed either to one of several detectors, an isotope harvesting area,