Five years ago, on Wednesday 4 August 2010, a lone power shovel began removing the first cubic metres of rock and top soil from the northern side of the ITER platform. In six months, some 230,000 cubic metres of material were excavated for the Tokamak Complex.
In parallel, 250 metres away, bulldozers and scrapers were levelling the ground at the site of a large winding facility for some of ITER’s largest magnets. After creating a smooth "sub-base," the concrete floor slab was poured and, within 18 months, a 257-metre-long steel structure erected.
Since then, the anti-seismic foundations of the Tokamak Complex have been set into place, drainage and precipitation networks finalized, a 400 kV electrical substation installed, and progress made on the Assembly Building—the 60-metre-high edifice that will host the pre-assembly operations for ITER machine components.
In five years, the moonlike landscape of 2010 has turned into a bustling environment of tall cranes, concrete and rebar, and steel columns rising as high as a 15-storey building.
The number of workers on the construction site will increase from 400 to 1,000 by the end of the year as the pace of construction accelerates and a number of ancillary buildings begin to rise. More than EUR 4 billion worth of contracts signed for ITER construction are acquiring a tangible shape on the ITER platform… (See the slideshows in this issue.)
As Newsline closes for its traditional summer recess, work inside of the offices and on the platform will continue at a determined pace, providing us with plenty of stories to report.
We’ll be back in late August with our next issue!
The ITER buildings are rising out of the ground, and now the ITER Organization is looking forward to the start of the next phase—the installation of the plant systems in the completed buildings and the assembly of the Tokamak itself.
In order to perform the installation of the components and utilities, which will involve around 2,000 workers at the peak, the ITER Organization will need the support of a Construction Management-as-Agent contractor (CMA). This contractor will work with the ITER Organization to plan, manage and supervise the works on the site—helping to ensure that all the different work crews are able to work most efficiently, having the right materials, drawings, documents and facilities to construct the ITER Tokamak and plant systems to high quality, on time and within cost.
Critical to the success of this next phase shall be integration and partnership between the project actors: the ITER Organization Central Team, the ITER Domestic Agencies, the CMA contractor and the works contractors.
The CMA will bring to the ITER Project industrial expertise in the areas of:
• planning, works contract management
• site coordination, material management
• works supervision, quality control, record keeping
• health, safety and environmental matters
• engineering support
• start-up and testing, maintenance management
The launch of the Call for Nominations for this contract marks the beginning of the process to place all the main contracts for the ITER assembly phase. As presented in the Assembly and Installation Information Day that was held on 21 May, the ITER Organization will also be launching the calls for nominations for the Machine Assembly, Piping and Mechanical Works and Electrical, I&C and Cabling Works contracts starting later this year.
Companies that wish to express an interest in the Construction Management-as-Agent contract shall express their interest through the ITER Organization Domestic Agencies. Full instructions are given on the ITER website.
Testing of the magnetic field in the Wendelstein 7-X fusion device has been completed sooner than planned. This fusion device of the stellarator variety located at the Max Planck Institute for Plasma Physics (IPP) in Greifswald, Germany is now in its commissioning phase in anticipation of a first plasma before the end of the year.
The measurements, completed in early July, show that the superconducting magnetic coils are producing the required magnetic field. The magnetic cage for the fusion plasma, which has a temperature of many million degrees, has a configuration that is in line with physicist calculations. This is an essential milestone in the operational preparations that are currently underway.
Although Wendelstein 7-X is not yet in operation, the experiment is already providing the first scientific results. The magnetic field meets the precise requirements for the confinement of the high-temperature fusion plasma as demonstrated by the first measurements of the field structure. 'We’ve got nice closed flux surfaces,’ Thomas Sunn Pedersen, the IPP Division Head responsible for this task, was pleased to announce.
How do you build a magnetic cage for the plasma? Fusion researchers make use of the fact that the charged plasma particles — ions and electrons — are kept on narrow spiral tracks around magnetic field lines by electromagnetic forces. As a result of a suitably formed field, the fast particles, as if guided on tracks, are kept away from the walls of the plasma vessel. To achieve a closed cage, the field lines in the centre of the circular plasma vessel must span closed, nested, circular surfaces like the growth rings inside a tree trunk. This prevents field lines pointing outwards, which would direct the plasma particles against the walls and make it impossible to achieve the high plasma temperatures required.
’Once the flux surface diagnostics were placed in operation, we were immediately able to see the first magnetic surfaces,’ reports Matthias Otte, who is responsible for the measurement process. 'Our images clearly show how magnetic field lines create closed surfaces in many toroidal circulations.’ The flux surface diagnostics enables the structure of the field to be precisely measured. For this purpose, a thin electron beam is injected and moves along a field line in circular tracks through the evacuated plasma vessel. It leaves behind a tracer, which is created by collision of the electrons with residual gas in the vessel. If, in addition, a fluorescent rod is moved through the vessel cross section, light spots are created when the electron beam hits the rod. In the camera recording, the entire cross section of the magnetic field gradually becomes visible.
During a single measurement that lasts around 60 seconds, the electron beam circulates many times on 'its’ field line in the circular plasma vessel and thereby covers a distance of several kilometres… 'Following the lengthy assembly time, we are now very pleased with the excellent measurement results,’ says Sunn Pedersen: 'The flux surfaces look just how we wanted them to appear.’
Read the full text of the Wendelstein 7-X press release here.
The ITER Test Blanket Module (TBM) program has begun to transition from scientific research to nuclear engineering and realization. Conceptual design work is currently underway on all six Test Blanket Systems planned for testing on ITER.
From 8 to 12 June, 30 experts came together in Barcelona to review the conceptual design of two TBM concepts put forward by Europe: the Helium-Cooled Pebble-Bed (HCPB) and the Helium-Cooled Lead Lithium (HCLL). (The key difference lies in the type of materials used for the tritium breeder.) By testing tritium concepts on ITER in a real fusion environment, scientists have a unique opportunity to explore the most promising techniques for tritium breeding that will be a critical technology for next-phase fusion devices.
Under the leadership of the European Domestic Agency for ITER, Fusion for Energy, European companies IDOM, Atmostat, AMEC Foster Wheeler, Empresarios Agrupados, Assystem, Iberdrola, and European fusion laboratories KIT, CEA, ENEA, CIEMAT, UJV, KFKI, NRG have been collaborating extensively to push back R&D frontiers.
During the Conceptual Design Review organized jointly by Fusion for Energy and the ITER Organization, years of hard work and engineering reports exceeding 1,500 pages were examined. Participants focused on verifying that the requirements of the systems had been properly taken into account in the design, that risks had been taken into consideration and minimized, and that all boundaries of the system in ITER had been established and secured. For Yves Poitevin, Fusion for Energy’s Project Manager for TBM systems, and his team, 'this has been a turning point for the field because years of R&D work have taken shape and evolved into an engineering design that one day will be a system in ITER.’
See the original article on the European Domestic Agency website.