Saito, Makiko; Ueno, Kenichi; Maruyama, Takahito; Murakami, Shin; Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka*; Tesini, A.*
Fusion Engineering and Design, 89(9-10), p.2352 - 2356, 2014/10
After plasma operation of the ITER reactor, irradiated radioactive dust will accumulate in the vacuum vessel (VV). The In Vessel Transporter (IVT) will be installed in the VV and remove the blanket modules for maintenance. The IVT will be carried back to the Hot Cell Facilities (HCF) after exchanging the blanket, and the IVT itself also needs maintenance. It is considered that the maintenance workers will be exposed to the irradiated radioactive dust attached to the IVT surface. In this study, dust contamination of the IVT is evaluated to assess exposure during maintenance work in the HCF. The IVT contamination scenario is assumed in the ITER project. From plasma shut down until maintenance is performed on the IVT will take 345 days under the ITER project assumption. Under this scenario, the effective dose rate from irradiated radioactive dust was calculated as an infinite plate for each nuclide. As a result, W-181 and Ta-182 were the dominant nuclides for the effective dose rate. If all dust is W-181 or Ta-182, the effective dose rate is about 400 Sv/h and 100 Sv/h respectively. Nevertheless, using the dose limit determined by the ITER project and the estimated maximum maintenance time, the effective dose rate limit was calculated to be 4.18 Sv/h under these limited conditions. To satisfy the dose rate limit, decontamination processes were assumed and the dose rate after decontamination was evaluated.
Maruyama, Takahito; Aburadani, Atsushi; Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Tesini, A.*
Fusion Engineering and Design, 89(9-10), p.2404 - 2408, 2014/10
Takeda, Nobukazu; Aburadani, Atsushi; Tanigawa, Hisashi; Shigematsu, Soichiro; Kozaka, Hiroshi; Murakami, Shin; Kakudate, Satoshi; Nakahira, Masataka; Tesini, A.*
Fusion Engineering and Design, 88(9-10), p.2186 - 2189, 2013/10
R&D for rail deployment equipment was performed for the ITER blanket remote handling system. The target torque for the automatic operation was investigated. The result shows that the 20% of the rated torque is adequate as the torque limitation for the automatic operation. A schedule for the procurement of the blanket remote handling system, which will be delivered to the ITER in 2020, was also shown.
Aburadani, Atsushi; Takeda, Nobukazu; Shigematsu, Soichiro; Murakami, Shin; Tanigawa, Hisashi; Kakudate, Satoshi; Nakahira, Masataka*; Hamilton, D.*; Tesini, A.*
Fusion Engineering and Design, 88(9-10), p.1978 - 1981, 2013/10
no abstracts in English
Takeda, Nobukazu; Kakudate, Satoshi; Matsumoto, Yasuhiro; Kozaka, Hiroshi; Aburadani, Atsushi; Negishi, Yusuke; Nakahira, Masataka*; Tesini, A.*
Fusion Engineering and Design, 85(7-9), p.1190 - 1195, 2010/12
Several R&Ds for the ITER blanket remote handling system had been performed from the Engineering Design Activity phase until now and only several technical issues regarding the control system remained such as noise caused by slip ring, control of cable handling system, signal transmission through very long cable and radiation-hard amplifier. This study concentrates on these issues. As a conclusion, major issues for the control system have been solved and the ITER blanket remote handling system becomes further feasible.
Nakahira, Masataka; Matsumoto, Yasuhiro; Kakudate, Satoshi; Takeda, Nobukazu; Shibanuma, Kiyoshi; Tesini, A.*
Fusion Engineering and Design, 84(7-11), p.1394 - 1398, 2009/06
Invessel components of ITER have to be maintained by remote handling (RH) equipment due to high radiation level in the vacuum vessel (VV) after D-D operation. Blanket module (BM) is maintained by a manipulator mounted on a vehicle traveled through an articulated rail deployed inside the VV. Towards the construction, the BLRH equipment design has been improved and developed in more detail. The overview of design results are introduced in this paper. The design of rail deployment system of the BLRH has been updated to enable the rail connection in the transfer cask in order to minimize occupation space. For this purpose, design works have been performed for concept, sequence and typical simulation of BL replacement in the VV and rail deployment of the RH equipment in the cask, including cask docking. The technical issues of the rail connection in the cask are (1) tight tolerance of a pin at a hinge, (2) limited space of the connection inside a cask and (3) tight positioning accuracy. This paper summarizes the idea to solve these issues and a result of the design work. The paper also introduces a new cable handling equipment, rail support equipment and BL receiver/transporter.
Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Matsumoto, Yasuhiro; Taguchi, Ko; Kozaka, Hiroshi; Shibanuma, Kiyoshi; Tesini, A.*
Fusion Engineering and Design, 84(7-11), p.1813 - 1817, 2009/06
The maintenance operation of the ITER in-vessel component, such as a blanket and divertor, must be executed by the remote equipment because of the high -ray environment. During the Engineering Design Activity (EDA), the Japan Atomic Energy Agency had been fabricated the prototype of the vehicle manipulator system for the blanket remote handling and confirmed feasibility of this system including automatic positioning of the blanket and rail deployment procedure of the articulated rail. The JAEA is continuing several R&Ds so that the system can be procured smoothly to ITER. The residual key issues after the EDA are rail connection, cable handling and in-situ replacement of first wall. The last issue is newly raised and currently under the discussion. This presentation concentrates on the former two issues.
Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Shibanuma, Kiyoshi; Tesini, A.*
Fusion Engineering and Design, 83(10-12), p.1837 - 1840, 2008/12
The maintenance activity in the ITER has to be performed remotely because 14 MeV neutron caused by fusion reaction induces activation of structural material and emission of ray. In general, it is one of the most critical issues to avoid collision between the remote maintenance system and in-vessel components. Therefore, the visual information in the vacuum vessel is required strongly to understand arrangement of these devices and components. However, there is a limitation of arrangement of viewing cameras in the vessel because of high intensity of ray. Furthermore, visibility of the interested area such as the contacting part is frequently disturbed by the devices and components, thus it is difficult to recognize relative position between the devices and components only by visual information even if enough cameras and lights are equipped. From these reasons, the simulator to recognize the positions of each devices and components is indispensable for remote handling systems in fusion reactors. The authors have been developed a simulator for the remote maintenance system of the ITER blanket using a general 3D robot simulation software "ENVISION". The simulator is connected to the control system of the manipulator which was developed as a part of the blanket maintenance system in the EDA and can reconstruct the positions of the manipulator and the blanket module using the position data of the motors through the LAN. In addition, it can provide virtual visual information, such as the connecting operation behind the blanket module with making the module transparent on the screen. It can be used also for checking the maintenance sequence before the actual operation.
Kakudate, Satoshi; Takeda, Nobukazu; Nakahira, Masataka; Matsumoto, Yasuhiro; Shibanuma, Kiyoshi; Tesini, A.*
Fusion Engineering and Design, 83(10-12), p.1850 - 1855, 2008/12
The design of in-vessel transporter (IVT) including vehicle manipulator has been updated according to the design changes such as blanket segmentation and structure, taking account of the interface between modules and vehicle manipulator. In particular, the updated design of the vehicle manipulator and rail has been carried out in order to avoid the interference between modules and vehicle manipulator. According to the updated design, the vehicle manipulator has been reduced by about 30%, compared with the reference design. In parallel with design activities, the R&D to clarify the specifications of the IVT design in detail is also performed, i.e., simulation system to provide the visual information during maintenance, dry lubricant to prevent the lubricant oil from spreading in the VV. The rail connection and cable handling in the transfer cask, which are critical issues for IVT system, are under preparation of the demonstration tests to finalize the design of the IVT system. Connection of the rail joint and cable handling test facilities are planned and under fabrication now. These test facility will be installed by the end of March 2008, and the performance tests will be carried out from April 2008.
Honda, Tsutomu*; Hattori, Yukiya*; Holloway, C.*; Martin, E.*; Matsumoto, Yasuhiro*; Matsunobu, Takashi*; Suzuki, Toshiyuki*; Tesini, A.*; Baulo, V.*; Haange, R.*; et al.
Fusion Engineering and Design, 63-64, p.507 - 518, 2002/12
The requirement to reduce the construction cost for ITER as compared with the 1998 ITER design, has led to a reduction in the size of the ITER machine and a number of design changes which have an impact on the remote maintenance of ITER. Major components to be considered for remote handling (RH) include the divertor cassettes, shield blanket modules, neutral beamline components, as well as in-port components, which are integrated with the port shield plug such as auxiliary heating equipment, limiters and test blanket modules. The design of the following equipment has been adapted for the smaller machine with reduced access space for the RH equipment: the RH equipment used for the in-vessel RH operationsto be deployed from the casks, the RH equipment that is used to remove the in-port assemblies (port plugs), as well as the remotely operated casks, which can be attached to and removed from vacuum vessel ports by using double -door systems. Defective components are loaded in transfer casks and moved to the hot cell facility by means of a remotely-operated air floatation system attached underneath the cask, where they dock against identical port interfaces and unload the component for remote refurbishment and/or waste storage.
Aburadani, Atsushi; Takeda, Nobukazu; Kakudate, Satoshi; Kubo, Tomomi*; Sugimoto, Takeru*; Nakahira, Masataka*; Tesini, A.*
no journal, ,
no abstracts in English
Aburadani, Atsushi; Kozaka, Hiroshi; Kakudate, Satoshi; Negishi, Yusuke; Matsumoto, Yasuhiro*; Nakahira, Masataka*; Tesini, A.*; Takeda, Nobukazu
no journal, ,
R&D for the major devices, rail deployment equipment and cable handling system, was performed for the ITER blanket remote handling system. Regarding the rail deployment, the relation between the Oldham's coupling used for the positioning arm and the positioning error at the end of rail was investigated. The result shows that the coupling allowing 4 mm displacement causes the positioning error of 19 mm. The possible countermeasures are suggested. Regarding the cable handling system, a possibility is shown to keep the cable tension at the adequate level by controlling the torque of the cable handling system. A schedule for the procurement of the blanket remote handling system, which will be delivered to the ITER in 2016, is also shown.