On the 23rd, Tokyo Electric Power Company (TEPCO) announced the results of its investigation inside the No. 2 reactor at the Fukushima Daiichi nuclear power plant, stating that extremely high levels of nuclear radiation were detected inside the reactor.
This is the first time since the nuclear accident at the Fukushima Daiichi nuclear power plant in 2011 that TEPCO has measured radiation inside the reactor core of a melted-down unit.
According to Japan Broadcasting Corporation (NHK), the investigation was conducted on the 16th. By inserting a fiber optic endoscope equipped with measuring instruments into the reactor through a pipe, radiation levels of approximately 4.7 sieverts per hour were measured at a point about 5 meters from the bottom of the reactor—an extremely high level.
TEPCO stated that the results of this investigation show that a certain amount of nuclear debris still remains inside the No. 2 reactor. The company will further analyze the relevant data and study ways to remove the nuclear debris.
On March 11, 2011, under the dual impact of the Great East Japan Earthquake and tsunami, the cores of Units 1 to 3 at the Fukushima Daiichi nuclear power plant suffered meltdowns, creating about 880 tons of nuclear debris. The nuclear debris is highly radioactive, and how to remove it is considered the biggest challenge in the decommissioning operation of the Fukushima Daiichi nuclear power plant.