ITER fiasco will accelerate the progress of fusion

The International Torus Experimental Reactor (ITER), a gigantic tokamak fusion device, has been hailed as the greatest single cooperative scientific endeavor in history, involving thousands of scientists and engineers from 35 nations.

A marvel of engineering, when completed ITER is intended for the first time to demonstrate large-scale net energy production by fusion reactions and provide the last stepping-stone to a prototype fusion power plant.

But from the outset the mind-boggling size and complexity of the system should have sounded alarm bells. Also the danger of creating a bureaucratic monster.

Since its construction began in 2010, ITER has been plagued by a virtually endless series of problems and delays, pushing the target date for completion back again and again. The reactor was originally supposed to go on line in 2016, but today construction is still ongoing.

The last official target was 2025. But in November 2022, the newly appointed ITER Director Pietro Barabaschi informed the public that the target date of 2025 was no longer realistic, and that additional problems had emerged, whose resolution would be “not a question of weeks, but months, even years.”

Last year defects were reported in two of the most important components of the reactor: the sector plates that are to be welded together to form the vacuum vessel of the reactor (its “combustion chamber”) and the reactor’s thermal shielding.

The French Nuclear Safety Authority ordered a halt to assembly of the vacuum vessel after discovering misalignments between the welding surfaces of the first two 440-ton vessel sections. These apparently had been damaged in transit from South Korea, where they were manufactured. Reportedly, the defects in the thermal shielding of the reactor will require removal and replacement of 23 kilometers of cooling pipes.

Difficulties of this sort are not unheard of in projects with many first-of-the-kind features. But when they come on top of an endless series of hitches and delays in ITER’s decades’-long history, one can only regard the project as a fiasco.

The ITER might yet have a happy end, but it will be different from the one originally intended. Even assuming operation were to begin in 2025, the official ITER scenario foresees an additional 10 years of experiments before the reactor begins operating with fusion-reaction-generating deuterium-tritium fuel.

If all goes well, it might take another five-to-10 years before ITER achieves the promised goal of a ten-fold “return on power” (500 MW of fusion power from 50 MW of input heating power).

Even then, ITER is designed not to generate electricity but only to lay the basis for constructing a first prototype electricity-generating fusion power plant – referred to as the “DEMO.” If successful, the “DEMO” would then provide the jumping-off point for commercial fusion plants, which might go on line early in the second half of this century.  

Needless to say, this scenario – if realizable at all – is intolerably long.

A blessing in disguise?

How will the sad story of ITER affect the prospects for fusion?

Ironically, I am convinced that the ITER fiasco will actually accelerate, rather than slow down, progress toward the practical realization of fusion power.

On the background of the world’s energy and environmental challenges, it is spurring governments and private capital to invest more in alternative scenarios which – taken together – hold the promise of realizing commercially viable fusion power on a far shorter timescale.

One indication is accelerated plans by China and Japan to build their own national “DEMO” plants, without necessarily waiting for the results of ITER to come in. Both nations have reactor projects underway, which could in effect substitute for the role of ITER and accelerate development on the basis of  knowledge and technologies that did not exist when the final design of ITER was approved, in 2001.

South Korea is designing a “K-DEMO” reactor, intended to generate approximately 2.2 GW of thermal power and supply over 500 MW to the electricity grid.

As these nations are participants in ITER, pronouncements concerning national DEMO reactors still present them, diplomatically, as successors to the ITER project. But there is an obvious effort to find ways to skip over the endless wait for ITER to go on line while, at the same time, drawing on the theoretical and experimental work carried out under the umbrella of ITER.

Unfortunately, in my view, the plans of various nations to build DEMO reactors all embrace the same basic model as the ITER:…