Radioactive material was found on the worker's face during a routine radiation test as he was leaving the site after decontaminating fences and other equipment in a room near the plant's No. 2 reactor building, and he was decontaminated immediately, Kyodo News reported, citing the plant operator Tokyo Electric Power Company.
The man in his 20s was wearing a protective full-face mask and suit while working, the report said.
The incident followed one in October when two men were hospitalized after they were splashed with radioactive liquid while cleaning the plant's Advanced Liquid Processing System, or ALPS, a water filtration facility.