International Nuclear and Radiological Event Scale


The International Atomic Energy Agency introduced the International Nuclear and Radiological Event Scale (INES) in 1990 to facilitate swift communication of safety-relevant information in the case of nuclear accidents. The scale is a logarithmic one quite like the MW or Moment Magnitude Scale used to measure the proportional magnitude of earthquakes. In the INES, each level on the scale denotes an accident almost 10 times more intense or severe than the preceding level. Being a man-made disaster, the intensity of a nuclear accident is more subject to interpretation as compared to an earthquake, where a more quantitative measurement is possible. The INES level is generally assigned much later than the event occurrence. Hence, its usefulness in assisting in such disasters is limited.