Fukushima Daiichi: Two Years On

Published: 11 March 2013

Two years after the accident at Fukushima Daiichi Nuclear Power Plant, work continues to ensure the damaged units remain stable and to prepare for the long and challenging task of decommissioning. The J-Village, formerly Japan's national soccer training centre, is the main rear base for operations at Fukushima Daiichi. Several thousand workers pass every day through the J-Village, where they change into protective clothing before travelling to the nuclear power plant about 20 km to the north. Workers and visitors to the Fukushima Daiichi plant undergo 'whole body count' screening. The process, which lasts 60 seconds, checks for internal radiation exposure. A general view of the Fukushima Daiichi site. The light blue building in the centre is Unit 2. Behind it is Unit 1, which has been covered by a new, off-white structure with a peaked roof. The tangled mass of metal and rubble is Unit 3. The top of Unit 4, whose damaged upper levels have been removed, is visible towards the right of the picture. In the distance, to the far left, stand the undamaged Units 5 and 6, which were built on higher ground and escaped the worst of the tsunami. Workers in protective clothing and masks outside the Emergency Response Centre, the main control hub at the Fukushima Daiichi site. The building, which is heavily shielded from on-site radiation, was completed just a few months before the accident to act as a seismically stable control centre in case of earthquake. Workers entering and leaving the Emergency Response Centre. Masks are worn outside the centre to prevent the inhalation of radioactive particles. Protective clothing includes a double layer of rubber gloves, and disposable overalls made of an extremely strong, lightweight fabric. Workers monitor the plant from the Emergency Response Centre. A live CCTV image of Units 1 and 2 appears on the screen behind. Due to high on-site radiation, many instruments have to be monitored remotely via CCTV. Units 1 and 2 are monitored via CCTV from a desktop computer in the Emergency Response Centre. Unit 1 has been covered with a new structure since the accident, to avoid further release of radioactive materials. Pressure gauges are monitored via CCTV from desktop and laptop computers in the Emergency Response Centre. Instruments in many parts of the plant have to be monitored remotely by CCTV because of high on-site radiation. Messages of support from Japanese and foreign well-wishers line the walls of the Emergency Response Centre. Storage tanks for contaminated water - a major challenge at the Fukushima Daiichi site. Highly contaminated water in the basement of the reactor buildings is pumped out and treated to reduce the level of radionuclides, particularly caesium, then recirculated to cool the reactor cores. But every day an additional 400 tonnes of groundwater seeps into the damaged reactor and turbine buildings, meaning that an ever-increasing amount of treated and untreated water needs to be stored. The total capacity of existing tanks is just over 240 000 cubic metres, and more are being built, putting a strain on available space. Unit 4 of Fukushima Daiichi Nuclear Power Plant. The remains of the building's upper levels, which were destroyed by a hydrogen explosion, have been removed to allow for construction of a cover, so that fuel stored in the Unit's spent fuel pool can be moved to a common pool. The surface of the spent fuel pool at Unit 4. At the time of the accident, Unit 4's reactor was under maintenance and the fuel had been transferred to the pool, where it remains under plastic floats and a temporary metal roof until it can safely be removed. Steel pillars and a concrete wall have been installed as reinforcement underneath the pool, but moving the fuel out of the damaged building is seen as a priority. The view from the top of Unit 4, towards Units 3, 2 and 1. The twisted metal and rubble in the middle distance is the top of Unit 3, where high radiation levels are slowing work to clear debris. The cranes have to be operated remotely from the Emergency Response Centre. Debris from the upper levels of Unit 4 lies beside the building. The rubble as been cut away to prepare for construction of a new cover, so that fuel can be moved from the Unit's spent fuel pool to a common pool. Rubble from the hydrogen explosion lies inside the damaged Unit 4 building. The wall to the right is the side of the spent fuel pool. Foundations for the new cover that will be constructed over Unit 4, to allow the spent fuel to be removed. Building work has progressed since this photograph was taken in December 2012. Plant operator TEPCO plans to start moving the fuel to a common spent fuel pool at ground level before the end of 2013. The lid of Unit 4's Primary Containment Vessel lies close to the reactor building. The reactor was shut down for maintenance at the time of the accident. © IAEA