23 Aug (NucNet): The Japanese Nuclear Regulatory Authority (NRA) refers to a report by the Tokyo Electric Power Company (Tepco), which says that water was discovered inside as well as outside the dike surrounding a tank used for intermediate storage of contaminated water at Fukushima-Daiichi nuclear power plant.
The event was first classified as a level-1 incident on the International Nuclear Events Scale (INES) and was later revised to a level-3 incident (‘serious incident’).
The revision was due to the reported high level of beta radioactivity of the leaked water – 80 million becquerels per litre – and the total amount of contaminated water (300 cubic metres), which correspond to the INES level-3 criteria.
NRA also said that the defence in depth of the storage tank was not sufficient with no safety provisions remaining, which is another reason for the level-3 classification of the incident.
Full report in database: NucNet News in Brief No. 205, 20 August 2013 and News in Brief No. 206, 21 August 2013.
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To contact the editor responsible for this story: Lubomir Mitev at lubomir.mitev@nucnet.org
