ITER Passes 50 Percent Marker on Journey to First Plasma

ITER under construction in October 2017. Image: ITER

ITER under construction in October 2017. Image: ITER

The International Thermonuclear Experimental Reactor (ITER), a project to prove that fusion power is both sustainable and producible on a commercial scale, reached a major milestone at the end of 2017 when construction work towards “First Plasma” passed 50 percent.

The announcement was made in a message sent by Bernard Bigot, the project’s director general, to officials in ITER-member governments. “The stakes are very high for ITER,” Bigot says. “When we prove that fusion is a viable energy source, it will eventually replace burning fossil fuels, which are non-renewable and non-sustainable. Fusion will be complementary with wind, solar and other renewable energies.”

ITER will use hydrogen fusion, controlled by superconducting magnets, to produce massive heat energy. Fusion energy is carbon-free, environmentally sustainable and much more powerful than fossil fuels, according to researchers. A pineapple-sized amount of hydrogen offers as much fusion energy as 10,000 tons of coal. Additionally, a fusion plant does not have the costs of high-level radioactive waste disposal associated with nuclear plants, nor the environmental cost, at fossil fuel plants, of releasing CO2 and other pollutants.

First Plasma, scheduled for December 2025, will be the first stage of operation for ITER as a functional machine. ITER will use two forms of hydrogen fuel: deuterium extracted from seawater and tritium bred from lithium inside the fusion reactor. If its fusion reaction is disrupted, the reactor will simply shut down without external assistance. And there is no physical possibility of a meltdown accident, according to ITER officials, as only tiny amounts of fuel are used—about two to three grams at a time.

Moving forward, scientists hope that studying the fusion science and technology at ITER will enable the optimization of future plants. Researchers predict that fusion plants could start to come on line as soon as 2040, but the exact timing will depend on the level of public urgency and political will that translates to financial investment.

For now, ITER has become one the most complex science projects in human history. Manufacturers worldwide have produced roughly 10 million specialized parts for the machine and shipped them to the ITER facility in France, where engineers are assembling them, piece-by-piece, into the final machine.

Its hydrogen plasma will be heated to 150 million degrees Celsius, ten times hotter than the core of the sun, to enable the fusion reaction. The process will occur in a donut-shaped reactor, called a tokamak, that is surrounded by a huge array of superconducting magnets cooled to -269°C. The magnets are central to the project, confining and circulating the superheated, ionized plasma away from the metal walls.

“Our design has taken advantage of the best expertise of every member’s scientific and industrial base,” says Bigot. “No country could do this alone. We are all learning from each other, for the world’s mutual benefit.”

Each of the seven ITER members—the European Union, China, India, Japan, Korea, Russia and the United States—is fabricating a significant portion of the machine. More than 80 percent of the cost of ITER, about $22 billion, will be contributed in the form of components manufactured in the member states. Many of these massive components must be precisely fitted—for example, 17-meter-high magnets—with less than a millimeter of tolerance.
The funding scheme means that most of the costs paid by a member are actually distributed to companies within that country. This platform allows companies working on ITER to build new industrial expertise in major fields—including electromagnetics, cryogenics, robotics and materials science. It has also led to innovation and spin-offs in other fields. For example, expertise gained from working on ITER’s superconducting magnets is already being used in other research projects.

The European Union is set to pay 45 percent of the total cost, with China, India, Japan, Korea, Russia and the United States each contributing nine percent equally. All members will share in ITER’s technology and receive equal access to the intellectual property and innovation that comes from building the machine.

When completed, the ITER tokamak will produce 500 megawatts of thermal power, a size suitable for studying “burning” or largely self-heating plasma—a state of matter that has never been produced in a controlled environment on Earth. In burning plasma, most of the plasma heating comes from the fusion reaction itself.

A future commercial fusion plant could be designed with a slightly larger plasma chamber, for 10-15 times more electrical power, according to ITER scientists. A 2,000-megawatt fusion electricity plant, for example, would supply two million homes.

The initial capital cost of such a 2,000-megawatt fusion plant would be in the range of $10 billion, according to researchers. These capital costs would be offset, they maintain, by extremely low operating costs, negligible fuel costs and infrequent component replacement costs over the 60-year-plus life of the plant. Capital costs will decrease with large-scale deployment of fusion plants, the researchers say, and at current electricity usage rates, one fusion plant would be more than enough to power a city the size of Washington DC.

“If fusion power becomes universal, the use of electricity could be expanded greatly, to reduce the greenhouse gas emissions from transportation, buildings and industry,” predicts Bigot. “Providing clean, abundant, safe, economic energy will be a miracle for our planet.”