The International Atomic Energy Agency has started its second review of decommissioning at the Fukushima Daiichi nuclear plant to check on progress and provide more information for the international community.

The IAEA mission will pay special attention to the problem of contaminated water at the plant and the removal of fuel from the No. 4 reactor building, said Juan Carlos Lentijo, the head of the mission, at a press conference in Tokyo.

To this end, the 19-person mission includes experts in water-related radiation and engineering issues, said Mr. Lentijo, who is also director of the agency’s nuclear fuel cycle and waste technology division.

“This will allow us to assess the situation in detail,” he told reporters, ahead of a meeting with the government and plant operator Tokyo Electric Power Co.9501.TO +0.55%

The mission will head to the site of the world’s worst nuclear accident in 25 years on Tuesday. The team will observe the decommissioning process through Friday and then return to Tokyo to hold meetings with Japan’s Nuclear Regulation Authority and other experts. The mission will report on its findings at a press conference on Dec. 4, according to a statement by the economy, trade and industry ministry.

Water containing radioactive materials has been leaking from storage tanks and drains at the plant into groundwater and the nearby ocean, raising concerns across the world that currents might spread radioactivity to faraway places. The amount of contaminated water requiring storage at the plant is constantly increasing since several hundred metric tons of ground water flowing into the site every day runs into the water cooling system for the melted reactor cores in units 1-3.

Tepco has also started removing fuel from the No. 4 reactor building and locating it at a more stable fuel storage pool nearby. The fuel removal, which started last Monday, marked the first step of cleanup process expected to take 30 to 40 years.

The IAEA first reviewed the decommissioning process in April.