Experts from the International Atomic Energy Agency (IAEA) have arrived in Fukushima city to observe efforts to decontaminate the area following the disaster at the Fukushima Daiichi nuclear power plant.
The 12-member team arrived as Japan announced the launch of long-term checks for thyroid abnormalities in local children.
The screenings will target 360,000 children who were aged up to 18 on 11 March, when a tsunami overwhelmed the plant, knocking out power to cooling systems and triggering meltdowns in three of its six reactors.
The IAEA inspectors will visit the facility, operated by Tokyo Electric Power (Tepco), as well as farms and schools where decontamination efforts are under way.
After the agency's first visit to the stricken plant in June, it criticised Tepco for failing to prepare for a large tsunami, but praised its post-disaster response.