Inside the ITER Assembly Hall, aided by a 20-meter-tall sector subassembly tool known as SSAT-2, the first of nine 40-degree wedge-shaped subassemblies that will make up the device’s tokamak is taking shape. On August 30, the ITER Organization announced that all the components of the first subassembly were in place on the SSAT-2. After the wings of the subassembly tool slowly close, locking two vertical coils in place around the outside of a vacuum vessel section that is already wrapped in thermal shielding, the completed subassembly will be ready for positioning in the ITER assembly pit in late October.

The European Commission last week adopted the Euratom Work Programme 2021–2022, implementing the Euratom Research and Training Programme 2021–2025, a complement to Horizon Europe, the European Union’s key funding program for research and innovation.

After a decade of design and fabrication, General Atomics (GA) is preparing to ship the first module of the central solenoid—the largest of ITER’s magnets—to the site in southern France where 35 partner countries are collaborating to build the world’s largest tokamak and the first fusion device to produce net energy.

On April 26, as the ITER Organization announced that magnet assembly had begun with the April 21 placement of the divertor coil in the bottom of the machine, the organization also published an Image of the Week that bears an unmistakable—and unintentional—resemblance to the Olympic rings. The pre-compression rings were being prepped for installation in the ITER Assembly Hall when the serendipitous arrangement was captured by Bruno Levesy, a project manager at ITER.

Coordinated federal and private industry investments made now could yield an operational fusion pilot plant in the 2035–2040 time frame, according to Bringing Fusion to the U.S. Grid, a consensus study report released February 17 by the National Academies of Sciences, Engineering, and Medicine (NASEM).

Developed at the request of the Department of Energy, the report builds on the work of the 2019 Final Report of the Committee on a Strategic Plan for U.S. Burning Plasma Research, and it identifies key goals, innovations, and investments needed to develop a U.S. fusion pilot plant that can serve as a model for producing electricity at the lowest possible capital cost.

“The U.S. fusion community has been a pioneer of fusion research since its inception and now has the opportunity to bring fusion to the marketplace,” said Richard Hawryluk, associate director for fusion at the Princeton Plasma Physics Laboratory and chair of the NASEM Committee on the Key Goals and Innovations Needed for a U.S. Fusion Pilot Plant, which produced the report.

Fusion energy is no longer a far-off goal. It is now routinely achieved at laboratory scale but requires more energy to control the fusion reaction than the fusion reaction has released.

The path to viable fusion power from a magnetically confined plasma source requires the creation of a burning plasma, whereby the primary heating source comes from the fusion reaction itself.

To begin to consider the economic viability of a fusion power plant, the reaction must have a significant energy gain, or “Q” factor (the ratio of output power to input heating power), in a reaction that is sustained over a time frame of minutes or hours.

Construction has begun on an international experiment—the ITER tokamak—that aims to achieve a sustained reaction, and numerous privately funded smaller experiments have the potential to move forward toward this goal.

Nuclear News reached out to companies in the fusion community to ask for insights into their ongoing work. All are members of the Fusion Industry Association. Most companies submitted briefs at a specified word count, while others ran long and some ran short. Their insights appear on the following pages.

Rendering of SPARC, a compact, high-field, DT burning tokamak, currently under design by a team from MIT and CFS. Source: CFS/MIT-PSFC - CAD Rendering by T. Henderson

The fusion community is reaching a "Kitty Hawk moment" as early as 2025, according to the Popular Mechanics story, "Jeff Bezos Is Backing an Ancient Kind of Nuclear Fusion."

That moment will come from magnetized target fusion (MTF), the January 25 story notes, a technology that dates back to the 1970s when the U.S. Naval Research Laboratory first proposed it. Now, however, MTF’s proponents say that the technology is bearing down to reach the commercial power market. The question is, Will it be viable before the competing fusion model of tokamaks, such as ITER, start operations?

The ST25-HTS tokamak.

Governments around the world have been interested in fusion for more than 70 years. Fusion research was largely secret until 1968, when the Soviets unveiled exciting results from their tokamak (a magnetic confinement fusion device with a particular configuration that produces a toroidal plasma). The Soviets realized that tokamaks were not useful as weapons but could produce plasma in the million-degree temperature range to demonstrate Soviet scientific and technical prowess to the world.

Following this breakthrough, government laboratories around the world continued to pursue various methods of confining hot plasma to understand plasma physics under extreme conditions, getting closer and closer to the conditions necessary for fusion energy production. Tokamaks have been by far the most successful configuration. In the 1990s, the Tokamak Fusion Test Reactor at the Princeton Plasma Physics Laboratory produced 10 MW of fusion power using deuterium-tritium fusion. A few years later, the Joint European Torus (JET) in the United Kingdom increased that to 16 MW, getting close to breakeven using 24 MW of power to heat the plasma.

(photo: ITER Project gangway assembly)

The promise of hydrogen fusion as a safe, environmentally friendly, and virtually unlimited source of energy has motivated scientists and engineers for decades. For the general public, the pace of fusion research and development may at times appear to be slow. But for those on the inside, who understand both the technological challenges involved and the transformative impact that fusion can bring to human society in terms of the security of the long-term world energy supply, the extended investment is well worth it.

Failure is not an option.

PPPL physicists Raffi Nazikian (left) and Qiming Hu, with a figure from their research. Photo: PPPL/Elle Starkman

Stars contain their plasma with the force of gravity, but here on earth, plasma in fusion tokamaks must be magnetically confined. That confinement is tenuous, because tokamaks are subject to edge localized modes (ELM)—intense bursts of heat and particles that must be controlled to prevent instabilities and damage to the fusion reactor.

Researchers at the Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) and at General Atomics (GA) recently published a paper in Physical Review Letters explaining this tokamak restriction and a potential path to overcome it. They have developed a new model for ELM suppression in the DIII-D National Fusion Facility, which is operated by GA for the DOE. PPPL physicists Qiming Hu and Raffi Nazikian are the lead authors of the paper, which was announced on August 10 by PPPL.

Those attending the livestreamed July 28 celebration in person (shown here from above) followed recommended social distancing measures.

First-of-a-kind components have been arriving in recent months at the ITER construction site in Cadarache, France, from some of the 35 ITER member countries around the world. The arrival on July 21 of the first sector of the ITER vacuum vessel from South Korea marks the beginning of a four-and-a-half year machine assembly process for the world’s largest tokamak, a magnetic fusion device designed to prove the feasibility of fusion as an energy source.

The 1,250-ton cryostat base is positioned over the ITER tokamak pit for installation. The base is the heaviest lift of the tokamak assembly. Photo: ITER

ITER, the world’s largest international scientific collaboration, is beginning the assembly of the fusion reactor tokamak that will include 12 essential hardware systems provided by US ITER, which is managed by Oak Ridge National Laboratory. The first major machine element to be installed is the 1,250-ton base of the cryostat, which was placed into the tokamak assembly pit on May 26. ITER is located in southeastern France.

ITER vacuum vessel section no. 6, shown here, was completely assembled in April. South Korea is providing four of the nine 40-degree vacuum vessel sections; Europe is providing the other five. Photo: ITER

South Korea’s Hyundai Heavy Industries (HHI) has completed work on the first vacuum vessel section for the International Thermonuclear Experimental Reactor (ITER), the ITER Organization reported on April 28. The 440-ton section is now being prepared for shipping this summer to the ITER construction site, located near Saint-Paul-lez-Durance, France.

Jacobs has been awarded several contracts to support work on the ITER fusion project. Photo: ITER Organization

The global engineering company Jacobs announced on April 14 that it has been awarded several contracts with an estimated combined value of more than $25 million. The contracts are with the ITER Organization, Fusion for Energy, and the United Kingdom Atomic Energy Authority (UKAEA) and are intended to support fusion energy projects in France and the United Kingdom.