18 Feb (NucNet): The situation at the Fukushima-Daiichi nuclear station in Japan remains “very complex”, with the increasing amount of contaminated water posing a short-term challenge and the need to remove highly radioactive spent fuel from the reactors that suffered meltdowns “a huge long-term challenge”, the International Atomic Energy Agency has said.
The IAEA’s third review of decommissioning plans for Tokyo Electric Power Company’s (Tepco) Fukushima-Daiichi found an “improved” situation with lower radiation in many areas, but added that many challenges to cleaning up the site remain.
Juan Carlos Lentijo, IAEA director of nuclear fuel cycle and technology, said in a statement that Japan has made significant progress since previous IAEA missions. The situation on the site has improved [and] progressive clean-up has led to reduced radiation dose levels in many parts of the site, he said.
But the situation remains very complex, with the increasing amount of contaminated water posing a short-term challenge that must be resolved in a sustainable manner. “The need to remove highly radioactive spent fuel, including damaged fuel and fuel debris, from the reactors that suffered meltdowns poses a huge long-term challenge,” he said.
On the issue of contaminated water, the IAEA team said there has been “persistent underground water ingress” to main buildings and the accumulation of contaminated water on-site. A statement said: “The IAEA team considered the current practice of storing contaminated water a temporary measure and highlighted the need for a more sustainable solution.”
The team examined a variety of issues related to decommissioning the station, focusing on the safety and technological aspects of decommissioning, radioactive waste management, control of underground water and accumulation of contaminated water at the site. The team looked at the planning and implementation of pre-decommissioning and decommissioning activities, including removal of spent and damaged fuel. The mission also reviewed progress achieved since two earlier missions carried out in 2013.
In a preliminary summary report delivered to Japanese authorities yesterday, the team acknowledged a number of accomplishments in preparing Fukushima-Daiichi for decommissioning.
Those accomplishments include the creation in 2014 of a new branch of Tepco, called Fukushima-Daiichi Decontamination and Decommissioning Engineering Company, as the only organisation responsible for the implementation of site radioactive waste management and decommissioning activities.
The team said the establishment of the Nuclear Damage Compensation and Decommissioning Facilitation Corporation as a national authority to develop a strategy for the decommissioning demonstrates “the proactive attitude of the government of Japan and Tepco towards addressing the many difficulties at the site”.
