IAEA team sees improvements at Fukushima Daiichi

Significant tasks have been completed in the clean-up and decommissioning of the damaged Fukushima Daiichi nuclear power plant, an international expert mission has concluded. However, it says many challenging issues remain.

Significant tasks have been completed in the clean-up and decommissioning of the damaged Fukushima Daiichi nuclear power plant, an international expert mission has concluded. However, it says many challenging issues remain.

The IAEA mission on the operating floor of the reactor building of unit 4 (Image: Tepco)

The 15-member team assembled by the International Atomic Energy Agency (IAEA) visited Japan between 9 and 17 February at the request of the country's government. The main purpose of the mission was to review revisions to the plan and implementation of decommissioning the Fukushima Daiichi plant.

The latest mission followed two similar missions in April 2013 and November-December 2013. The first of those was to carry out an initial review of Japan's mid- and long-term roadmap towards decommissioning the plant. The second was to provide a more detailed review of the revised roadmap and mid-term challenges.

Water purification demo

RosRAO has commissioned Atomproekt to develop documentation for construction of a demonstration plant to test technology for a water treatment facility at the Fukushima Daiichi plant. The technology would purify water contaminated with tritium.

RosRAO and Atomproket are subsidiaries of Russian state nuclear corporation Rosatom.

St Petersburg-based Atomproekt aims to develop by the end of June a conceptual design and working documentation for the facility with construction of the demonstration unit to start in early 2016.

If the demonstration plant is successful, a full-scale facility could be built at the plant to remove tritium from 400 cubic meters of liquid radioactive waste (LRW) per day.

The government of Japan selected RosRAO and the Khlopin Radium Institute last year as partners for the demonstration project.

Atomproekt and RosRAO will draw on their experience of their Triton project, started in 2011, for processing LRW contaminated with tritium ready for its safe disposal.

RosRAO began operations in 2009 for the management of used nuclear fuel, non-nuclear radioactive waste, and decommissioning services, especially of submarines. Then in 2011, NO RAO was created to consolidate these activities as the national manager of Russia's used nuclear fuel and radioactive waste. RosRAO aims to be a global provider of back-end fuel cycle services.

Atomproekt - the former VNIPIET (All-Russia Science Research and Design Institute of Power Engineering Technology), which since 2013 incorporates St Petersburg Atomenergoproekt (SPbAEP) - designs nuclear power projects, radiochemical plants and waste facilities.

In its preliminary report, the team of experts noted: "The situation on-site has been improved since the last IAEA mission in 2013. Several important tasks were accomplished such as completion of the removal of fuel from unit 4; the improvement and expansion of contaminated water treatment systems; the installation of new tanks and associated systems for contaminated water storage; the operation of underground water bypass; and the clean-up of the site resulting in the enhanced working radiological environment."

Team leader Juan Carlos Lentijo, director of the IAEA's nuclear fuel cycle and waste technology division, said: "The situation, however, 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 added, "The path ahead is long, complex and challenging. Japan is progressing step-by-step and plans are taking shape, which is a welcome development. It is important to maintain safety as the highest priority during all steps of the decommissioning of the site."

The team also noted Tokyo Electric Power Company's (Tepco's) creation last year of a new branch - the Fukushima Daiichi Decontamination and Decommissioning Engineering Company - as "the only responsible organization for the safe implementation of the on-site radioactive waste management and decommissioning activities." This, it said, "is a good step forward to clarify responsibilities."

In addition, the IAEA said the establishment of the Nuclear Damage Compensation and Decommissioning Facilitation Corporation as a national authority to develop guiding strategy for the decommissioning "demonstrates the proactive attitude of the government of Japan and Tepco towards addressing the many difficulties at the site."

Tepco's chief decommissioning officer Naohiro Masuda said, "The IAEA peer review has acknowledged our progress at Fukushima Daiichi, such as in the management of radioactive waste and contaminated water, removal of used fuel assemblies and reduction of dosage on the site and in the vicinity. The IAEA has also given us valuable points for improvement and we look forward to their continued advice."

The IAEA team plans to submit its final report to Japan by the end of March.

Researched and written
by World Nuclear News