Exposure levels detected by radiation monitors worn by workers were found to be as much as 10 becquerels per square centimeter – 2.5 higher than the safe radiation exposure level – said Tokyo Electric Power Company (TEPCO), the plant’s operator responsible for decommissioning.
The affected were ordered to receive full body scans, which can detect radiation exposure to internal organs.
Workers at the Fukushima Daiichi plant might have come into contact with contaminated mist water from devices used to cool temperatures around the Main Anti-earthquake building while waiting for a bus, TEPCO said.
The employees said that when they were near the device, the alarm indicating an increased level of radiation went off.
The cooling devices were turned off and workers at the building were prohibited from using tap water, which comes from the same source.
Meanwhile, earlier on Monday, an alarm indicating a high radiation dose went off at the continuous dust monitor installed in front of the main building, TEPCO said.