The International Thermonuclear Experimental Reactor (ITER) under construction at Saint-Paul-les-Durance in southern France is facing more delays, ITER director general Pietro Barabaschi said in an interview with AFP.
ITER is a first-of-a-kind global collaboration to construct the world’s largest tokamak based on magnetic confinement technology. It is funded mainly by the European Union (45.6%) with the remainder shared equally by China, India, Japan, Korea, Russia and the USA (9.1% each). However, in practice, the members deliver little monetary contribution to the project, instead providing ‘in-kind’ contributions of components, systems or buildings. In November, Barabaschi, who was appointed to head the project in September, announced that defects had been identified in two key tokamak components, the thermal shields and the vacuum vessel sectors. He warned that the consequences on schedule and cost ''will not be insignificant''.
ITER'S previous target was to create the plasma by 2025 but Barabaschi said it would have to be postponed, adding that the date "wasn't realistic in the first place” even before the problems were identified. One problem, he said, was incorrect sizes for the joints of blocks to be welded together for the installation's 19 x 11 metre chamber. The second was traces of corrosion in a thermal shield.
Fixing the problems "is not a question of weeks, but months, even years," he noted.
A new timetable will be worked out by the end of this year, including some modification to contain the expected cost overrun, and to meet the French nuclear safety agency's security requirements. Barabaschi said he hoped ITER would be able to make up for the delays as it prepares to enter the full phase, currently scheduled for 2035.
In December researchers at the Lawrence Livermore National Laboratory (LLNL) in California, using a different technology based on laser ignition, reported that they had, for the first time, achieved a fusion reaction generating more energy than it took to produce. Commenting on this development, Barabaschi told AFP, "Some competition is healthy in any environment," adding: "If tomorrow somebody found another breakthrough that would make my work redundant, I would be very happy."
However, ITER’s latest technical difficulties are not the first. In January 2022, French regulator Autorité de Sûreté Nucléaire ordered ITER to halt assembly of the vacuum vessel after finding misalignments between the welding surfaces of the first two 440-ton stainless-steel vessel sections. The pair, the first two of nine segments that when joined will form a torus that contains the fusion plasma, had been damaged in transit from South Korea. ASN also told the ITER Organisation that the two-metre-thick concrete radiological shielding to be installed around the reactor was inadequate to protect personnel once the facility began operation and expressed concern that any increase to the shielding could cause the total weight of the reactor to exceed the 140?000-ton capacity of its earthquake-resistant foundation. ITER is currently working to resolve these issues. ITER says the Covid pandemic has also caused delays.
According to the American Institute of Physics (AIP), there have also been issues relating beryllium at ITER causing Robert Winkel, the organisation’s expert on beryllium to resign after supervisors ignored his recommendations and failed to consult him on occupational exposure to the metal. The ITER vacuum chamber walls are to be lined with 12 tons of beryllium to protect them from damage by fusion neutrons and to absorb stray oxygen molecules. Kathryn Creek, also a beryllium expert and Winkel’s wife, left her job two years before, blaming pressure from managers to water down her recommendations on beryllium protections, AIP said.
There have also been problems at Fusion for Energy (F4E), the EU body that manages Europe’s share of in-kind contributions to the project, which has faced employee complaints of poor management and excessive workloads. The organisation has experienced a case of suicide and a number of strikes. F4E’s director, Johannes Schwemmer, told a European Parliament hearing that a “psychosocial-risk-assessment survey” had found the excessive workload to be a “risk factor” for the F4E workforce. F4E is currently managing 98 separate ITER component projects, each having an average value of about €100m. F4E management has requested its governing board and the European Commission for approval to hire 34 additional employees.
Image courtesy of ITER Organization