An excessively radioactive cement truck on Saturday ignored a decontamination order at the Fukushima No. 1 plant and drove to the town of Naraha, the company said.
The driver neglected the decontamination order and left the premises at around 1:25 p.m. despite knowing its readings were too hot, Tokyo Electric Power Co. officials said.
The truck returned about an hour and 10 minutes later after getting a load of fresh concrete at a factory in the town of Naraha.
A radiation check later conducted at the power plant showed the truck was giving off a Geiger counter reading of 22,000 counts per minute near the upper part of its rear bumper.
Vehicles must have Geiger readings of 13,000 cpm or less to leave the plant.
Tepco said it confirmed that the contaminated truck didn’t negatively impact any areas outside the plant.