| The uncertain future of fusion energy|
' ITER will not only be the largest fusion reactor to date, but also quite possibly the most ambitious engineering project in history and the most complex machine mankind has ever attempted to build. With partners including the European Union, the United States, Russia, China, India, Japan, and South Korea (even Iran wants in), ITER is turning out to be the sort of political and logistical challenge that could be expected of an international collaboration of this magnitude, particularly one of such long duration. Unfortunately, but not surprisingly, budget and schedule overruns reflect this reality. ITER’s current budget is on the order of $18 billion (no one knows for sure), first plasma is expected in 2025, and the intended fusion reaction of deuterium-tritium will not begin until 2035. Obviously this schedule may continue to slide, especially if ITER remains underfunded.
American funding for ITER is directed toward domestic contributions, such as the central solenoid, a superconducting magnet being provided by General Atomics. Other critical American supplied subsystems include the cooling water system, the vacuum pumping system, and a host of diagnostics. Of the roughly $400 million the U.S. government typically spends annually on fusion research, about half is supposed to go to ITER development. However, the federal fusion budget is being cut to just over $300 million, and the current budget request for ITER is only $63 million; as of now the Senate does not have ITER funding in its budget at all.
Not funding ITER will result either in ITER’s incompletion or in ITER’s success without American participation. With Canada long since withdrawing, the U.K. considering doing so, and the United States underfunding its commitment, ITER’s future is by no means secure. “ITER is a key stepping stone required for commercializing fusion. If we pull it off, we will have a clean, abundant energy source on the grid in probably 30 to 35 years. If we don’t fund fusion, we risk blocking this path for generations,” says Mark Henderson, a physicist working at ITER.
Unlike their government-backed brethren, whose fundamental purpose is plasma physics research, fusion start-ups are narrowly focused on building practical reactors for power generation. Burnaby, British Columbia based General Fusion is developing a fusion reactor that uses a toroidal plasma design similar to that in a tokamak. Instead of surrounding the plasma with an array of giant magnets, General Fusion is surrounding the plasma in a swirling vortex of liquid lead-lithium. The metal vessel containing the swirling lead-lithium will then be surrounded by an array of pistons. These pistons will compress the liquid in a coordinated way to subsequently compress the plasma at the center to a density high enough to sustain a fusion reaction.
If General Fusion’s liquid lead concept sounds audacious, an even more radical idea is being pursued by Foothill Range, CA based Tri Alpha Energy. Like General Fusion, Tri Alpha Energy’s idea is based on technology developed in the 1970’s, has remained largely under-explored, and is now advancing with the benefit of high-speed computing and precision controls that were not available forty years ago. Instead of a tokamak, Tri Alpha Energy’s vessel uses field-reversed configuration (FRC), which is also a magnetic confinement device, but one in which the magnetic field lines are contained in the vessel without the need for a central channel (the “hole” in the tokamak bagel).
Other fusion start-ups are also pursuing unique reactor designs. Redmond Washington’s Helion Energy has raised around $20 million, including from the U.S. Departments of Energy and Defense. Helion Energy is building a fifth prototype and hopefully the first to break-even on energy balance, with plans to subsequently develop a 50-megawatt direct energy conversion device. The UK’s Tokamak Energy is taking a more conventional approach, through miniaturizing tokamak technology. Tokamak Energy has recently achieved first plasma in their latest prototype and is aiming to deliver fusion power at commercial scale by 2030. Others such as Lockheed Martin and start-up Focus Fusion are also pursuing their own concepts.'