The neutral beam system will launch high-energy particles to heat up the ITER plasma. Up to three neutral beam injectors will provide 16.5 MW of heating power each to help reach the 150 million °C needed for ITER’s fusion reaction. These injectors will be located in the neutral beam cell, an area in the Tokamak building with radiation levels too high to allow access to humans. For this reason, any maintenance works on the neutral beam will be carried out using remote handling systems.
The Monorail Crane is the backbone of the neutral beam’s cell remote maintenance system, as most operations will depend on it. Therefore, its design needs to ensure that it will function in all possible scenarios, and will recover as easily as possible from any potential failure. Despite its name, a two-rail system will be attached to the ceiling of the cell – engineers saw that this configuration was more convenient than a single rail, but kept the original name! A trolley will be able to move along the railway, hanging from it, like an upside down train carriage going through a city crammed with buildings. The trolley will lift the defined loads for the beam line components and the beam source, using adaptors designed to interface with the individual components. From a control room, the crane will be operated to perform any maintenance, and repair the pieces of the neutral beam system by transporting the bespoke tools to the required locations in the cell.
Experts from F4E wanted to make sure that they were putting in place an appropriate system. With Jacobs and REEL, they prepared a prototype of the crane to test most of its features. They started the manufacturing of the first components in 2020 and assembled the crane the year after. Testing was carried out with very satisfactory results. “The manufacture and testing of the crane system prototype is the culmination of more than seven years of collaboration between F4E, ITER Organization and industry partners (Jacobs and REEL) and serves as a tribute to the efforts of the team, and particularly to Marco van Uffelen, who led the project until his untimely passing. It has proven with this design that the heaviest loads can be safely moved through the tightest curves expected for the real system layout in the neutral beam cell,” explains Kevin Smith, F4E Remote Handling.
Denis Fichot, REEL New Reactors Manager, gives us more details. “The prototype demonstrates that this innovative remote handling equipment will perform as planned in normal or degraded conditions during construction and maintenance phases of the neutral beam cell. Any lessons learned from these successful tests will be included in the final design. It was also an opportunity to start preparing the future site installation. REEL is fully involved in this project working closely with F4E and progressing towards first plasma.”
Now that engineers are confident with the component, they are focusing on the final design of the system. A new contract, currently under negotiation, will address this and other related activities to complete the neutral beam remote handling system.