About 300 tons of highly radioactive water has leaked from a storage tank at the stricken Fukushima nuclear plant in Japan, according to Tepco, the plant’s operator.
In a statement TEPCO said that the water level in one of the 1000-ton steel tanks was found to be down by a third.
A TEPCO employee found a big puddle of water outside the tank on Monday morning.
This tank is one of a group of 26 similar tanks near reactor No.4 in which contaminated water is being stored. The stored water became contaminated with radioactive strontium, cesium and tritium when it was used to cool the crippled reactors.
The water has a concentration of 80 million becquerels per litre, which translates into 24 trillion becquerels for 300 tons. A radiation level of 100 millisieverts per hour was detected near the surface of a puddle around the tank.
The figure is 100 times the government’s annual limit of radiation exposure for the public. (Becquerel is a measure of radioactivity in a substance while sievert is a measure of radioactivity received by living tissue, like in a human being.)
‘This means you are exposed to the level of radiation in an hour that a nuclear plant worker is allowed to be exposed to in five years,’ a TEPCO official told reporters.
The Nuclear Regulation Authority on 19 August provisionally rated the
incident as a Level 1 ‘anomaly’ on the eight-level International Nuclear and Radiological Event Scale (INES), one notch above Level 0 ‘deviations,’ which have
no safety significance.
The earthquake and tsunami of 11 March, 2011 had destroyed the nuclear plant causing a meltdown in its reactors. The catastrophe had been given the highest Level 7 designation under the INES.
In a statement TEPCO said that the water level in one of the 1000-ton steel tanks was found to be down by a third.
A TEPCO employee found a big puddle of water outside the tank on Monday morning.
This tank is one of a group of 26 similar tanks near reactor No.4 in which contaminated water is being stored. The stored water became contaminated with radioactive strontium, cesium and tritium when it was used to cool the crippled reactors.
The water has a concentration of 80 million becquerels per litre, which translates into 24 trillion becquerels for 300 tons. A radiation level of 100 millisieverts per hour was detected near the surface of a puddle around the tank.
The figure is 100 times the government’s annual limit of radiation exposure for the public. (Becquerel is a measure of radioactivity in a substance while sievert is a measure of radioactivity received by living tissue, like in a human being.)
‘This means you are exposed to the level of radiation in an hour that a nuclear plant worker is allowed to be exposed to in five years,’ a TEPCO official told reporters.
The Nuclear Regulation Authority on 19 August provisionally rated the
incident as a Level 1 ‘anomaly’ on the eight-level International Nuclear and Radiological Event Scale (INES), one notch above Level 0 ‘deviations,’ which have
no safety significance.
The earthquake and tsunami of 11 March, 2011 had destroyed the nuclear plant causing a meltdown in its reactors. The catastrophe had been given the highest Level 7 designation under the INES.