Skunk Works To Build Compact Fusion Reactor
Lockheed Martin’s Skunk Works, famous for creating, among other things, the U-2 & SR-71 spy planes and the F-117 stealth fighter, shocked the world of physics research by announcing that they are going to build a compact fusion reactor. The proposed compact fusion reactor (CFR) is conceptually safer, cleaner and more powerful than much larger, current nuclear systems that rely on fission. Governments and industry have poured billions of dollars into fusion research for half a century with little success. Can Lockheed's vaunted engineers succeed where armies of PhDs have failed? If so, the arguments over energy, the environment and de-industrialization are over—or are they?
There is an old joke that goes, “nuclear fusion is the power source of the future, and it always will be.” The idea of nuclear fusion, in which atoms combine into more stable forms, releasing excess energy in the process, is not new. In the 1920s it was first hypothesized that fusion powers the Sun and other stars. Since then scientists have struggled to harness this form of energy here on Earth. Today, research institutions, government laboratories and companies around the world are actively pursuing ideas for fusion power, but none have gone beyond the experimental stage. After quietly working on the problem for a decade, aerospace giant Lockheed Martin has made public its in-house project with the aim of attracting partners, resources and additional researchers.
Thomas McGuire, an aeronautical engineer in the Skunk Work’s aptly named Revolutionary Technology Programs unit, leads the project known internally as “T4.” Current efforts are focused on a containment vessel roughly the size of a business-jet engine, a stark contrast with other research reactors such as the National Ignition Facility, used as a set in a recent Star Trek movie, and ITER, being built by an international consortium of fusion researchers. Both of those projects are working on prototypes weighing tens of thousands of tons.
Speaking at the announcement press conference, held at the company’s facility in Palmdale, California, McGuire defended the project’s scientific merits: “We think we’ve invented something that is inherently stable,” McGuire told reporters. But he acknowledged that “we are very early in the scientific process.”
“I studied this in graduate school where, under a NASA study, I was charged with how we could get to Mars quickly,” says McGuire, who earned his Ph.D. at the Massachusetts Institute of Technology. Scanning the literature for fusion-based space propulsion concepts proved disappointing. “That started me on the road and [in the early 2000s], I started looking at all the ideas that had been published. I basically took those ideas and melded them into something new by taking the problems in one and trying to replace them with the benefits of others. So we have evolved it here at Lockheed into something totally new, and that’s what we are testing.”
Since the announcement the entire field has been abuze. Science magazine published a technical summary:
[McGuire] said that [his group’s] magnetic confinement concept combined elements from several earlier approaches. The core of the device uses cusp confinement, a sort of magnetic trap in which particles that try to escape are pushed back by rounded, pillowlike magnetic fields. Cusp devices were investigated in the 1960s and 1970s but were largely abandoned because particles leak out through gaps between the various magnetic fields leading to a loss of temperature. McGuire says they get around this problem by encapsulating the cusp device inside a magnetic mirror device, a different sort of confinement technique. Cylindrical in shape, it uses a magnetic field to restrict particles to movement along its axis. Extra-strong fields at the ends of the machine—magnetic mirrors—prevent the particles from escaping. Mirror devices were also extensively studied last century, culminating in the 54-meter-long Mirror Fusion Test Facility B (MFTF-B) at Lawrence Livermore National Laboratory in California. In 1986, MFTF-B was completed at a cost of $372 million but, for budgetary reasons, was never turned on.
Another technique the team is using to counter particle losses from cusp confinement is recirculation. “We recapture the flow of particles and route it back into the device,” McGuire said. The team has built its first machine and has carried out 200 shots during commissioning and applied up to 1 kilowatt of heating, but McGuire declined to detail any measurements of plasma temperature, density, or confinement time—the key parameters for a fusion plasma—but said the plasma appeared very stable. He said they would be ramping up heating over the coming months and would publish results next year.
McGuire acknowledged the need for shielding against neutrons for the magnet coils positioned inside the reactor vessel. He estimates that between 80 and 150 centimeters of shielding would be needed, but this can be accommodated in their compact design. Researchers . . . say that it is difficult to estimate the final size of the machine without more knowledge of its design. Lockheed has said its goal is a machine 7 meters across, but some estimates had suggested that the required shielding would make it considerably larger.
The majority of previous fusion reactors have been based on tokamak, a plasma containment system invented in the 1950s by Soviet physicists Igor Tamm and Andrei Sakharov, inspired by an original idea of Oleg Lavrentiev. A tokamak uses a magnetic field to hold the plasma in the shape of a torus, or ring, and maintains the reaction by inducing a current inside the plasma itself with a second set of electromagnets. The problem with this approach is that the energy generated is almost the same as the energy required to maintain the self-sustaining fusion reaction—not a good return on a multibillion dollar investment.
Comparing a tokomak torus to a bicycle tire, McGuire commented in an Aviation Week & Space Technology article: “if they put too much in, eventually their confining tire will fail and burst—so to operate safely, they don’t go too close to that.” Shying away from the limits makes such devices inherently inefficient. The CFR avoids these problems by tackling plasma confinement in a radically different way. Instead of constraining the plasma within tubular rings, a series of superconducting coils will generate a new magnetic-field geometry which holds the plasma within the reaction chamber, shown below.
McGuire and team expect to have a working prototype in five years. An initial production version could follow that in five years, so ten years from now they are hoping to take fusion power commercial. The first commercial reactors will be designed to generate around 100 MW and fit into transportable units measuring 23 X 43 ft. “That’s the size we are thinking of now. You could put it on a semi-trailer, similar to a small gas turbine, put it on a pad, hook it up and can be running in a few weeks,” McGuire says. A 100-MW unit would provide power for up to 80,000 homes and is also “enough to run a ship,” he notes.
Others aren't giving up the race for fusion, however. Tim Frazier, CIO for National Ignition Facility and Photon Science Principal Associate Directorate, Lawrence Livermore National Laboratory recently said, “fusion will be a huge clean-energy breakthrough.” They and ITER will continue to develop their own fusion concepts. And Lockheed Martin is not the only one to announce a new “breakthrough” in fusion power. Researchers at the University of Washington claim to have invented a simpler fusion reactor that is more economical than a coal-fired power plant, yet produces zero green house gases.
The design, called a spheromak, began as a class project by professor Thomas Jarboe, but had not been proven a viable design until a prototype called the Dynomak was recently built by Jarboe and doctoral candidate Derek Sutherland, who had previously worked on reactor designs at the Massachusetts Institute of Technology (MIT). So the race is on for fusion power. Indeed, fusion power is the Holy Grail of energy research. But what would happen if Lockheed's or Dr. Jarboe's reactor works?
Such a development would send tremors through the power generation industry. The fuel for nuclear fusion is deuterium, a form of hydrogen with both a proton and a neutron in its nucleus. For all intents and purposes the world's oceans hold an unlimited supply of deuterium in the form of heavy water. It would certainly hasten the demise of the coal industry. Not that coal would disappear all together. Metallurgical coal would still be used for smelting iron ore, but wide spread coal use for electrical generation would decline over a number of decades.
It would also put a major crimp in the wind and solar industries. Fusion would be what is called base load power, a steady supply of energy that doesn't depend on the time of day or environmental conditions. Given recent revelations of birds and bats being slaughtered by both wind and solar plants, any true conservationists would quickly drop their support for these expensive “green” energy sources. The only other thing needed to end the burning of fossil fuels would be usable electric cars and trucks, surely something that can be accomplished in the next twenty or thirty years. Besides, it would take that long to phase out gas and diesel vehicles through wear and tear, and also give industry time to retool and build an electric recharging infrastructure. If it works, greens should embrace fusion as mankind's salvation. But would they?
Fusion could mean a clean green future for everyone.
Fusion would be a permanent, clean solution to the world's energy needs. There would no longer be a need to scrimp and save energy. Many of the tenets of green driven conservation would become unnecessary. There would no longer be any rational reason to de-industrialize the world. And there in lies a problem. Many eco-activists and global warming alarmists are only using CO2 emissions as cover for deeper agendas. Cheep clean energy will be the acid test for disingenuous radicals, hiding draconian social policies behind supposedly saving the planet from the ravages of climate change. Humanity will still have to deal with the pains of development and growth, but the greatest scientific hoax of the 21st Century would collapse like a house of cards. There would no longer be an ecological need for world socialism or the demise of capitalism; their hidden plans would have to stand on their own merits.
Be safe, enjoy the interglacial and stay skeptical.