ITER to be given a new timetable
The project operators of the ITER nuclear fusion research project are responding to a number of technical and other problems that have arisen in recent years.
A segment of the vacuum vessel that needs to be repaired.
(Image: ITER)
A new timetable is emerging for the international nuclear fusion project International Thermonuclear Experimental Reactor (ITER). At the most recent meeting of the ITER Council, a reform was discussed which aims to "streamline" project management and pay greater attention to quality control. For example, tests before the assembly of components are to be improved. There is also a need to respond to delays caused by the coronavirus pandemic and "technical challenges".
After around two years of deliberations on the reform, it emerged that the research reactor will initially operate with deuterium-deuterium (DD) from 2035, followed by operation with full magnetic energy and plasma current. ITER Director-General Pietro Barabaschi will present details of this next week, according to a statement from the ITER Council (PDF). Once these steps have been taken, the project can move on to the fusion of deuterium with tritium. DD is also suitable for researching how a fusion plasma can be produced and maintained. Deuterium is much easier to produce than tritium. Moreover, unlike deuterium, the latter is radioactive.
Previous delays
This is not the first change to the ITER schedule. Originally, the research reactor in Cadarache in southern France, which was initiated by the EU together with the USA, China, India, Japan, Russia and South Korea in 2006, was due to go into operation in 2016. At the end of 2015, the project operators assumed that the first plasma would be ignited in 2025 at the earliest, that the system would not be switched on before 2025 and that the first deuterium-tritium fusion reaction would not be achieved until ten years later, i.e. 2035.
A year ago, there were already indications that the commissioning of ITER would be delayed even further due to a number of technical problems: The dimensions of segments of the vacuum vessel show excessive deviations. There are also traces of corrosion on the heat shield – helium could escape there. Progress has been made in repairing or correcting these components. The extent of this is not clear from the press release.
In ITER, heavy hydrogen (deuterium) is to fuse with super-heavy hydrogen (tritium) to form helium, which is only possible at temperatures between 150 million and 300 million °C. The plasma is therefore to be confined within a ring-shaped vacuum chamber by a strong magnetic field and heated using various technical processes. The neutrons released in the process cannot be contained by the magnetic field, so components of the reactor are activated over time.
(anw)
