Results 1 - 10 of 1745
Results 1 - 10 of 1745. Search took: 0.024 seconds
|Sort by: date | relevance|
[en] Upon release of radioactive materials by the accident at Fukushima Daiichi Nuclear Power Station on March 11, 2011, the Government of Japan as well as the prefectural and the municipal governments have been taking measures to decontaminate polluted soils in order to reduce the impact of radioactive pollution of the environment on human health and the living environment as soon as possible. In the efforts for the decontamination, all available resources including those from the central and the local government offices, research institutions, and private cleaning operators are put together, along with the scientific and technical knowledge available from Japan and abroad. Our primary objective is to eliminate the recurrence of such a disaster in the future, but in the meantime, disclosing and sharing our knowledge, experience, and lessons obtained through the decontamination efforts this time with domestic peers and the international community will be significant to accelerate the decontamination work in Japan and minimize the potential damage in future accidents in Japan and abroad for the implementation of expeditious and efficient decontamination. Therefore, the Ministry of the Environment (MOE) published “Decontamination Report” and the report comprehensively compiles the basic policy of the decontamination and implementation framework, knowledge about the management of decontamination projects based on the actual decontamination operations on-site, together with the procedure, conditions and effects of individual decontamination techniques, by mainly focusing on the decontamination operations performed by MOE.
[en] Various Research and Development (R and D) efforts related to the retrieval of damaged fuel debris at Fukushima Daiichi Nuclear Power Plant in Japan have been made since the accident occurred in March 2011. Since 2012, the Primary Containment Vessel (PCV) Repair Project has been one of the major improvement tasks required in the reactor buildings in order to start fuel debris retrieval activities. The primary purpose of this project is to create a water boundary in the lower sections of the PCV using remote handling methods. A designated long reach remote manipulator for this project, called the Fukushima Repair Manipulator (FRM), has been developed to perform inspection, light demolition, and deployment of various tools to supply sealing material to fill the vent tubes as a part of the PCV Repair Project. The FRM is a single hydraulic manipulator which has 7 degrees of freedom, over 9 m reach, tool change capability and a payload of 50 kg at maximum reach. These features provide a safe, robust, efficient and allow for flexible operations in limited access and visibility around the operating area. This paper will provide a system description of this manipulator and planned remote operations for the PCV Repair Project. (authors)
[en] The Nuclear Damage Compensation and Decommissioning Facilitation Corporation (NDF) was set up by Japanese Government decision in August 2014, as an organization specializing in formulation of strategies and provision of technical support by integrating the knowledge and experiences from all over the world with the objectives of safe and steady decommissioning of damaged reactors. Since then efforts have been made to study the specific strategies to address major challenges of decommissioning from the mid-and-long-term viewpoint, and NDF formulated the first version of the “Technical Strategic Plan” in April 2015, and is going to revise and formulate its 2016 version by summer of 2016. The goals of this “Strategic Plan” are to provide a firm technical basis for the government’s mid-and-long-term Roadmap and to serve as an aid for smooth and steady implementation of decommissioning.
[en] IHI has developed a procedure of making an access opening on Biological Shield Wall (hereinafter called BSW) of the first floor in the reactor building. Some organizations have also developed the retrieval methods for top and side access. Top access is to set up the retrieval equipment on the refueling floor where is top of the reactor building. Another method, side access is to deploy those on the first floor. Top access would spend a long time due to long approach between the refueling floor and RPV. Side access is expected to make a shorter way than that of top access, if debris is on the pedestal bottom. Each method will require making a large opening on the building in order to approach fuel debris. In this report, IHI introduces a plan of making an access opening on the BSW in side access. (authors)