The Japan Atomic Energy Agency (JAEA), Hitachi-GE Nuclear Energy Ltd and Sugino Machine Limited have signed a joint research agreement to develop a laser process technology for decommissioning nuclear reactors. Hitachi-GE has extensive experience with boiling water reactors and Sugino specialises in water-jet cutting technology.
JAEA has developed remotely controlled laser-cutting technology that can be used in narrow space and enables the amount of secondary waste to be reduced. It has been investigating the cutting characteristics of thick steel plates in underwater environments at the Fugen advanced thermal reactor (ATR). Hitachi-GE is developing technology for decommissioning and decontaminating Fukushima Daiichi. Sugino Machine is developing remotely-controlled equipment and devices that can operate in highly-radioactive environments.
Under the agreement, the three parties will co-operate to develop new cutting methods for use within reactors making possible the application of laser technology to the decommissioning of Fukushima Daiichi. The three companies plan to use the Naraha Remote Technology Development Centre, which is under construction by JAEA in Fukushima prefecture and which is scheduled to begin full operation in the 2016 fiscal year.
Work set to resume on cover dismantling
Tokyo Electric Power Company (Tepco) says it will resume work to dismantle the cover unit 1 at Fukushima Daiichi NPP on 28 July as long as weather conditions permit. Tepco installed the cover to prevent radioactive material from dispersing after a hydrogen explosion damaged the reactor building. The utility initially planned to start dismantling the cover last year to clear radioactive rubble and remove used nuclear fuel from the pool inside the building.
The plan was postponed several times, however, in face of public concern about the dispersal of radioactive substances. Engineers also found a problem with a device that controls the air flow in the building when dismantling work was set to begin in May. The problem has now been addressed. Chemical agents will be sprayed to prevent radioactive dust from being released into the air. Engineers plan to remove the six roof panels in about 4-months' time.
Testing starts on new radiation data system
Meanwhile, the Nuclear Regulation Authority (NRA) is testing a new radiation data-publicising system for residents living near nuclear power plants. NRA has begun to test-run the system in an area around the Sendai NPP in Kagoshima Prefecture, which Kyushu Electric Power Company hopes to bring the plant back online in August.
The new system enables the central government and municipalities to provide radiation data online for other organisations as well as for local residents during emergencies. The system will allow users to access a special site on the Authority's website to obtain data in the event of a nuclear accident. The Sendai plant website provides updated figures from 73 observation points within a 30km radius from the plant, as well as from cars equipped with radiation-monitoring equipment.
Figures appear in red or yellow when they exceed government standards. The new nuclear emergency guidelines, which were revised following the Fukushima accident, call for the evacuation of residents within a 5-30km radius of a power plant if radiation levels exceed the government limit. NRA plans to launch the system in August after one month of testing and will also set up websites for other nuclear plants.