
The world’s biggest and most expensive nuclear fusion research project, known as ITER, says it’s halfway done with the construction effort leading to the startup of its seven-story-high reactor in 2025.
ITER’s ambition to demonstrate a sustained fusion reaction that produces a net gain in energy is matched by the estimated cost, which exceeds $20 billion.
The 35-nation consortium began construction a decade ago, under an unusual arrangement that calls for the various countries to contribute components for the reactor taking shape at Cadarache in southern France. The United States is responsible for 9 percent of the total cost.