Construction of the International Thermonuclear Experimental Reactor (ITER) in southern France is costing almost four times the original estimate, but the ITER project's new head says new forecasts are realistic, Reuters reported.

The project was launched 10 years ago  by the seven ITER partners – Europe, United States, China, India, Japan, Russia and South Korea – at an estimated cost of €5bn ($5.6bn) with plans to heat the first plasma by 2020 and to  achieve full fusion by 2023. By 2011, the budget forecast had swollen to about €16bn and in May, new ITER chief Bernard Bigot said ITER would be delayed by more than a decade and incur another 4 billion euros of cost overruns, with the first test of its super-heated plasma not before 2025 and first power not before 2035.

He confirmed this on 7 October during a visit to the ITER site in Cadarache. He estimates the overall cost until commissioning will be around €18bn. "For the first time, we have a reliable estimate … In the past there was no realistic schedule, no detailed appreciation of the cost … It was much underestimated," he said. However, a precise estimate is difficult as partner countries contribute most of their shares in the project in kind, by producing components. "Many domestic agencies do not want to disclose their exact costs," he said, adding that the running cost of the ITER organization plus the domestic agencies in the partner countries is about €200m a year.