noun
International Nuclear Event Scale; INES
A scale used to classify the severity of nuclear and radiological events, from Level 0 (deviation) to Level 7 (major accident).
福島第一原子力発電所の事故は、国際原子力事象評価尺度でレベル7と評価された。
The Fukushima Daiichi nuclear accident was rated Level 7 on the International Nuclear Event Scale.
Calque from English 'International Nuclear Event Scale'; the Japanese term is a direct translation of the English name.