Tokyo Electric Power Company has detected extremely high levels of radiation inside one of the crippled reactors of the Fukushima Daiichi nuclear power plant.
It says radiation levels increased as the dosimeter was lowered inside the reactor. This suggests the nuclear fuel melted down and collected at the bottom of the vessel.
The utility also learned the water level inside the vessel was only 60 centimeters, compared to the original estimate of about 3 meters.
TEPCO suspects the suppression chamber at the bottom of the vessel may have been destroyed.
Lethal radiation detected inside Fukushima reactor
Tokyo Electric Power Company has detected extremely high levels of radiation inside one of the crippled reactors of the Fukushima Daiichi nuclear power plant. TEPCO was able to place monitoring equipment directly inside the reactor for the first time since last year’s accident.
A dosimeter lowered into the containment vessel of the No.2 reactor registered 72.9 sieverts, or 72,900 millisieverts per hour at maximum — a level where a human is certain to die within about 7 minutes of exposure. The utility hopes to determine the state of the vessels as it moves to decommission the reactors.
It says radiation levels increased as the dosimeter was lowered inside the reactor. This suggests the nuclear fuel melted down and collected at the bottom of the vessel. The utility also learned the water level inside the vessel was only 60 centimeters, compared to the original estimate of about 3 meters.
TEPCO suspects the suppression chamber at the bottom of the vessel may have been destroyed. The findings are a setback for plans to scrap the reactor. The utility has to pinpoint and repair damaged parts inside the vessel and fill it with water before extracting the fuel. TEPCO says the development of devices that can withstand the extremely high levels of radiation is a pressing matter.