Straight Dope on Medicine: Nuclear Fusion

Author

Scott Ganser
June 05, 2023

Nuclear fusion is humanity’s hope for a clean, unlimited source of energy, and has been so for the last 60 years. Physicists have been studying fusion power since the 1950s.[i]

The difference now is that we have crossed a barrier.

Last December, fusion scientists produced more energy from an ignition experiment than they put in.

Now we just have to jump higher over that barrier.

A matter of degree and not kind.

At the center of the grand scheme is the US National Ignition Facility (NIF).

An Experiment

NIF, based at Lawrence Livermore National Laboratory (LLNL) in California, is a stadium-sized facility that fires 192 lasers at a tiny gold cylinder containing a diamond capsule. Inside the capsule sits a frozen pellet of the hydrogen isotopes deuterium and tritium. The lasers trigger an implosion, creating extreme heat and pressure that drive the hydrogen isotopes to fuse into helium, releasing additional energy.[ii]

This is called inertial confinement.

This process is extremely demanding, requiring exceptionally precise beam focusing and ultra-smooth capsules to ensure the near perfectly symmetrical implosions needed for fusion.[iii]

In the long term, the goal is to increase the amount of energy generated by fusion reactions from the 3.15 megajoules created last year to hundreds of megajoules. The input was 2.05 megajoules. They got 54% more energy out than they put in.

Net Gain

That is the entire game.

A net gain result in a fusion experiment essentially means producing more energy through fusion reactions than the amount of energy put into the system to start said reaction.

This is usually measured as a Q factor, which is the ratio of energy out to energy in. For decades, the holy grail in fusion science has been achieving Q > 1.

A Q factor of more than 1 means you got out more energy than what you put into the fuel. This is generally known as “scientific breakeven”. The result announced today translates to a Q factor of about 1.5.

For fusion to be commercially viable, they need Q=10.[iv]

There really is no limit to the upper bound of what Q could be. If we get really, really good at this, we might have Q of 10,000 or 1,000,000.

Energy Capture

This is a problem. It’s like the dog that chases the car down the road. If he catches it, he doesn’t know what to do with it.

He will just stand there and bark.

Fusion reactions produce mainly thermal energy. Capture systems like steam generators are at most 60% efficient. So, even the small gain that they get, the inefficiency can still lead to a net loss.

What’s next?

More is less.

Max Karasik, a physicist at the Naval Research Laboratory in Washington DC, this highlights a potential path forward that he and others are pursuing: jettison the gold cylinder and focus the lasers directly on the fuel pellet, an experimental design known as direct drive.

In this configuration, “there is much more energy available for compressing the fuel pellet”, Karasik says.

Government incentives

Over the next 18 months, the DOE is looking to dole out US$50 million in grants to private fusion companies in a milestone-based program modelled on NASA’s partnership with space-transport firms such as SpaceX. Laser-fusion companies will compete with firms pursuing other fusion designs, however. One of the most popular is the tokamak, a device that creates a magnetic field to contain the burning plasma generated by a fusion reaction in a doughnut-shaped ‘torus’. This is the approach being used by the world’s largest fusion experiment, ITER, in Saint-Paul-lès-Durance, France.

With plasma, how do you bottle it at a temperature of around 100 million kelvins, several times hotter than the center of the sun?

Answer: in a “magnetic bottle” formed by strong magnetic fields so it never touches the walls of the fusion chamber.

Credit: Mark Belan

Obsolete

With disruptive technology, older technology gets disrupted or outright ended. That would be a good thing, for some of this is obvious garbage and will probably never do the job.

When I was traveling up to the Grand Victorian in Rockford, Illinois to see my father, I came across a few, butt-ugly wind mill farms. Almost none of these monstrosities was turning. How are we supposed to get electricity if these perpetual motion machines aren’t turning?

They were just sitting there idle.

I’d rather see trees, waterfalls and crops than these abominations.

What a waste of space!

These eyesores can go the way of the dinosaur.

The trash can is waiting.

Commercial

Longview Fusion Energy Systems. Set up in 2021 by several former Livermore scientists, including ex-NIF director Edward Moses, Longview aims to combine NIF’s target design with diode-pumped solid-state lasers. The company announced its existence on the same day that Livermore reported NIF’s record-breaking shot, saying that it planned to start building a pilot power plant within the next five years.

Longview says that it intends to provide 50 MW of electricity to the grid by 2035 at the latest. The company acknowledges that this will not be easy, envisaging a laser efficiency and repetition rate of 18% and 10–20 Hz respectively. In particular, it says that while the necessary diodes already exist, they have “not yet been packaged into an integrated beamline for a fusion-scale laser”.

from proof-of-concept to early commercialization for energy technologies (IEA, 2020).

Moo

To that end, Longview has signed a MOU.

- Fluor Corporation (NYSE: FLR) announced today that it has signed a memorandum of understanding (MOU) with Longview Fusion Energy Systems, Inc. to serve as its engineering and construction partner in designing and planning laser fusion energy for the global energy market.

At full capacity, Longview’s laser fusion power plants (1,000–1,600MW) are slated to provide carbon-free, safe, economical and sustainable energy that can power the needs of a small city or provide process heat or power to drive industrial production of the materials needed for operational necessities like steel, fertilizer and hydrogen fuel.[v]

Japanese Fusion

fusion reactor in the world, the JT-60SA, is located at Japan Atomic Energy Agency's Naka Fusion Institute. Image: JT-60SA[vi]

The Japanese government has opted to build up a huge domestic fusion industry to secure a leading role in the future commercial utilization of fusion power. This policy is clearly set forth in a document published on April 14 by the Japanese Cabinet, entitled “Fusion Energy Innovation Strategy.” The new policy goes far beyond merely stepping up the participation of Japanese industry and scientific institutes in international projects.

Kyoto Fusioneering is raising big new money from domestic venture capital funds, banks and energy, engineering and trading companies, the latest indication that nuclear fusion energy ventures are becoming increasingly investible in Japan.[vii]

German Fusion

ral Platform says: “Stellarators offer the most robust and clearest path to fusion energy. The Proxima team has the energy and the speed that we need. They are ecosystem players, with a thrilling sense of ambition building on top of the Wendelstein 7-X stellarator – a masterpiece of German leadership. Europe needs the audacity of this team and their willpower to take on the fusion challenge.”

Munich’s Proxima Fusion, incorporated in January, aims to build a complex device known as a stellarator and is the latest company to join the emerging fusion industry’s effort to generate electricity by fusing atoms. Although the amount of funding is small at only €7mn, it is significant as Proxima is the first fusion company to spin out of Germany’s revered Max Planck Institute for Plasma Physics.[viii]

What is a stellarator?

Answer: a plasma donut.

In the 1950s astrophysicist Lyman Spitzer argued that plasma might be contained more effectively in a doughnut chamber with a twisted tunnel wall. With this configuration, the device could keep the plasma constrained by using the magnetic fields generated by flows in the charged plasma itself.

The more complex geometry of this design, called a stellarator, is tricky to engineer, but a few projects are pursuing it. A notable example is the Wendelstein 7-X stellarator in Greifswald, Germany, completed in 2015 and now operating again after a three-year upgrade. “A stellarator has some advantages, but technically it's a more complicated device,” Donné says.

The Way

The largest fusion project in the world, ITER (Latin for “the way” and originally an acronym for “International Thermonuclear Experimental Reactor”) in southern France, will use a massive tokamak with a plasma radius of 6.2 meters; the entire machine will weigh 23,000 metric tons. If all goes to plan, ITER—supported by the European Union, the U.K., China, India, Japan, South Korea, Russia and the U.S.—will be the first fusion reactor to demonstrate continuous energy output at the scale of a power plant (about 500 megawatts, or MW). Construction began in 2007.

Fly me to the moon.

Let me dance among the stars.

 According to Chinese state media, the Chinese Atomic Energy Authority has confirmed the presence of helium-3 inside the crystal (from the moon from China's Chang’e-5 mission in 2020). This isotope of helium is rare on Earth, but scientists (and science-fiction authors) have long speculated it could be present in significant amounts on the moon. Compared with other forms of the element, helium-3 produces fewer radioactive byproducts when going through fusion.[ix]

The Earth has an estimated 20kg of tritium in global reserves.

A commercial Tokamak is going to burn through 300 grams per day. That means we have 2 months operation with the entire world’s supply.

The way around this is to generate tritium on site by using lithium. This they call a “lithium breeding blanket.” This isn’t free. It costs energy, and may drastically reduce the net output.

Take a walk on the wild side.

There is a wild card in the mix. This one goes by the name Helion. They have combined magnetic and inertial confinement in their design to give us the best of both worlds.

Helion has signed a deal with Microsoft to supply them with 50 megawatts of fusion power by 2028.

In addition to the new design, they use different fuel: deuterium and helion (helium-3).

They have been able to do 10,000 high-powered fusion reactions non-stop for 16 months.

They also believe they will have greater efficiencies.

Helion’s next effort is called “Polaris.” It will be larger and more powerful than Trenta, their current machine. All hopes are being pinned on it.

Big wigs at the company say that they will get electricity production out of Polaris by 2024.

What else is out there?

Plenty. For the gory, gory details, watch the video.

How would our world change?

Once we learned how to conduct the process in a controlled and sustained manner, some scientists predicted, electricity would become “too cheap to meter.”

The detestable World Economic Forum has chimed in.

I don’t know whether or not they are championing this or not, because their foremost motivation is control.[x]

Not a drop to drink: water

Access to fresh water is drying up around the world, focusing attention on desalination (desal) technology, which can make plentiful drinking water from the sea. But one problem that has always hampered desal remains: it requires a huge amount of energy. In 2019, a US Department of Energy report said: “The ability to bypass these energy costs could potentially be critical for development.”

That ability could come from commercial fusion energy, creating a game changer for desalination by taking the energy overhead costs of desal and cutting them to nearly zero.

Made in your zip code: manufacturing

For centuries, the location of any kind of mill or other factory in the US was predetermined: you had to build it alongside a river, with the current pushing through a water wheel. As technology developed in the early 1800s, turbine systems could power mills of all sorts. More recently, factories still need some proximity to high-wattage transmission lines that can supply large quantities of electricity. But with fusion power, industrial planning would be upended: just about anyone could have as much energy as they need, practically anywhere.

Factories could, for example, be located closer to the raw materials they rely on — or to the retail markets that goods are destined for — cutting down on transportation costs and carbon emissions. Reshoring manufacturing from Asia and overseas to the US already cuts down on emissions both from shipping and production (for example, Chinese factories often rely on coal-fired power plants). With fusion powering the factory (and the logistics infrastructure too), those reductions would be even greater.

How we move: transportation

The already booming electric car market is set to grow even more with the new $7,500 electric vehicle tax credit that was included in the sweeping climate measures in the US Inflation Reduction Act. And with the Biden Administration planning to build 500,000 “fast”-level charging stations (capable of topping off an electric battery in about 30 minutes) across the country by 2030, the electric vehicle revolution is finally here and fusion will only make it better by reducing emissions and costs for charging all of those new gas-free cars.

Within electric vehicles, there’s an energy ecosystem that needs improvement to make electric vehicles a more viable choice for everyone too. To help address that, TAE recently spun off a new company called TAE Power Solutions to create advanced technologies designed to deliver faster charging, stronger performance, greater range and longer battery life for e-mobility and stationary applications.