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May 24, 2013

Nuclear Fusion Summary - Prospects for breakthrough commercial reactors 2018-2025

Nuclear fusion is one of the main topics at Nextbigfuture. I have summarized the state of nuclear fusion research before. A notable summary was made three years ago in mid-2010. I believed at the time that there could be multiple successful nuclear fusion project vying for commercial markets by 2018. Progress appears to be going a bit more slowly than previously hoped, but there are several possible projects (General Fusion, John Slough small space propulsion nuclear fusion system, Lawrenceville Plasma Physics - if they work out metal contamination and other issues and scale power) that could demonstrate net energy gain in the next couple of years.

Commercialization Date targets

General Fusion 2020 (targeting 4 cents per kwh)

Helion Energy 2022 (about 5 cents per kwh and able to burn nuclear fission waste)

Lockheed Compact Fusion 2023

Tri-Alpha Energy (previously talked about 2015-2020, but now likely 2020-2025)

Lawrenceville Plasma Physics - 4 years commercial after net energy gain proved. Say two years to prove net energy gain. Then 2019-2021 for a commercial reactor (2021 if we allow for 2 years of slippage). Could lower energy costs by ten times.

EMC2 Fusion (?? No information for the last few years. US Navy is funding the work at a few million dollars per year)

Muon Fusion - Research in Japan and at Star Scientific in Australia

There will be more than one economic and technological winner. Once we figure nuclear fusion there will be multiple nuclear fusion reactors. It will be like engines - steam engines, gasoline engines, diesel engines, jet engines. There will be multiple makers of multiple types of nuclear fusion reactors. There will be many applications energy production, space propulsion, space launch, transmutation, weapons and more. We will be achieving greater capabilities with magnets (100+ tesla superconducting magnets), lasers (high repetition and high power), and materials. We will also have more knowledge of the physics. What had been a long hard slog will become easy and there will be a lot more money for research around a massive industry.

The cleaner burning aspect of most nuclear fusion approaches versus nuclear fission is not that interesting to me. It is good but nuclear fission waste cycle could be completely closed with deep burn nuclear fission reactors that use all of the uranium and plutonium. In China it is straight up engineering questions. So a transition to moderately deeper burn pebble bed from 2020-2035 (starts 2015 but not a major part until 2020) and then a shift to breeders 2030-2050+.

What matters are developments which could radically alter the economy of the world and the future of humanity. The leading smaller nuclear fusion projects hold out the potential of radically lowering the cost of energy and increasing the amount of energy. Nuclear fusion can enable an expansion of the energy used by civilization by over a billion times from 20 Terawatts to 20 Zettawatts. Nuclear fusion also enables space propulsion at significant fractions of the speed of light (1 to 20% of lightspeed.) Earth to orbit launch with nuclear fusion spaceplanes or reusable rockets and trivial access to anywhere in the solar system.



General Fusion targeting commercial reactor for 2020 and funding does not seem to be a problem

General Fusion is trying to make affordable fusion power a reality.

• Plan to demonstrate proof of physics DD equivalent “net gain” in 2013
• Plan to demonstrate the first fusion system capable of “net gain” 3 years after proof
• Validated by leading experts in fusion and industrial engineering
• Industrial and institutional partners
• $42.5M in venture capital, $6.3M in government support

General Fusion intends to build a three-meter-diameter steel sphere filled with spinning molten lead and lithium. Super-heated plasma would be injected into the vortex and then the outside of the sphere would be hit with 200 computer-synchronized pistons travelling 100 meters per second (200 mph) The resulting shock waves would compress the plasma and spark a fusion reaction for a few microseconds.


Tri-alpha Energy - Raised about $140 million + Rusnano investment. Best funded of the smaller players

In 2013, Rusnano Group, a state-owned venture firm, invested an undisclosed amount in Tri-Alpha Energy. The Russian investment is the latest round of financing for Tri-Alpha which, prior to the Rusnano backing, is believed to have raised over $140 million from Goldman Sachs, venture capital firms including Venrock, Vulcan Capital and New Enterprise Associates, Microsoft co-founder Paul Allen, and others.

Tri-alpha revealed some information in a 79 page powerpoint deck in 2012

The design of a 100 MW reactor is underway. Test “shots” to demonstrate plasma confinement are in progress. It is based upon field reversed research but it seems they are migrating towards a pulsed colliding beam approach that looks more similar to Helion Energy. In the picture below, look closely at the cylinder in front of the person. It looks like the Helion Energy design.


Tri-alpha is still secretive but what has been revealed about progress does not indicate a breakthrough has yet been achieved to net energy gain. Tri-alpha energy has previously talked about getting to a commercial system by 2018.

Helion Energy and MSNW - John Slough Designs

Helion Energy Fusion Engine has received about $7 million in funds from DOE, the Department of Defense and NASA. They had already received $5 million which they used to build a one third scale proof of concept. The company hopes to raise another $2 million by next year, $35 million in 2015-17, and $200 million for its pilot plant stage.

The MSNW LLC (sister company to Helion Energy working on Space fusion) does refer to the Helion Energy work. MSNW is working on a NASA grant to develop direct nuclear fusion space propulsion. They have said they will demonstrate net energy gain within 6-24 months.

Fusions Assumption:
• Ionization cost is 75 MJ/kg
• Coupling Efficiency to liner is 50%
• Thrust conversation ~ 90%
• Realistic liner mass are 0.28 kg to 0.41 kg
• Corresponds to a Gain of 50 to 500
• Ignition Factor of 5
• Safety margin of 2: GF =GF(calc.)/2

Mission Assumptions:
• Mass of Payload= 61 mT
• Habitat 31 mT
• Aeroshell 16 mT
• Descent System 14 mT
• Specific Mass of capacitors ~ 1 J/kg
• Specific Mass of Solar Electric Panels 200 W/kg
• Tankage fraction of 10% (tanks, structure, radiator, etc.)
• Payload mass fraction =Play load Mass
• System Specific Mass = Dry Mass/SEP (kg/kW)
• Analysis for single transit optimal transit to Mars
• Full propulsive braking for Mar Capture - no aerobraking



The Fusion Engine is a cyclically operating fusion power plant technology that will be capable of clean energy generation for base load and on-demand power.

The Fusion Engine is a 28-meter long, 3-meter high bow tie-shaped device that at both ends converts gases of deuterium and tritium (isotopes of hydrogen) into plasmoids - plasma contained by a magnetic field through a process called FRC (field-reversed configuration). It magnetically accelerates the plasmoids down long tapered tubes until they collide and compress in a central chamber wrapped by a magnetic coil that induces them to combine into helium atoms. The process also releases neutrons.

The Helion Energy Fusion Engine provides energy in two ways. Like in a fission reactor, the energy of the scattered neutrons gives off heat that ultimately drives a turbine. Helion is also developing a technique that directly converts energy to electricity. The direct conversion will provide about 70 percent of the outgoing electricity according to Kirtley.

Helion Energy new plan is to build a 50-MWe pilot of its “Fusion Engine” by 2019 after which licensees will begin building commercial models by 2022.



Lockheed Skunkworks Fusion - Targeting Commercial by 2023

Lockheed presented at Google Solve for X a 100MW compact fusion reactor concept that would run on deuterium and tritium (isotopes of hydrogen). It would fit on a truck and be built on a production line like jet engines.


Breakthrough technology: Charles Chase and his team at Lockheed have developed a High Beta configuration, which allows a compact reactor design and speedier development timeline (5 years instead of 30).

* The magnetic field increases the farther that you go out, which pushes the plasma back in.
* It also has very few open field lines (very few paths for the plasma to leak out)
* Very good arch curvature of the field lines
* The Lockheed system has a beta of about 1.
* This system is DT (deuterium - tritium)





Currently a cylinder 1 meter wide and 2 meters tall. The 100 MW version would be about twice the dimensions.




Lawrenceville Plasma Physics

The LPP approach uses a device called a dense plasma focus (DPF) to burn aneutronic fusion fuels that make no radioactive waste, a combination LPP calls “Focus Fusion.” LPP has taken major strides towards their goal.

Net fusion energy is like a tripod, and needs three conditions to stand (or in the LPP case, get more energy out than is lost). Despite FF-1’s low cost of less than $1 million, the results LPP published showed FF-1 has achieved two out of three conditions—temperature and confinement time—needed for net fusion energy. If they were able to achieve the third net fusion energy condition, density, they could be within four years of beginning mass manufacture of 5 Megawatt electric Focus Fusion generators that would scale to meet all global energy demands at a projected cost 10 times less than coal. While we still must demonstrate full scientific feasibility, FF-1 already achieves well over 100 billion fusion reactions in a few microseconds.

Lawrenceville Plasma Physics - Progress and specific issues to be resolved to boost plasma density by 100 and then to increase current

In the past month’s experiments, LPP’s research team has demonstrated the near tripling of ion density in the plasmoid to 8x10^19 ions/cc, or 0.27 mg/cc. At the same time, fusion energy output has moved up, with the best three shot average increasing 50% to one sixth of a joule of energy. While the yield and density improvements show we are moving in the right direction, they are still well below what the LPP team theoretically expects for our present peak current of 1.1 MA. Yield is low by a factor of 10 and density by a factor of nearly 100. If we can get yield up to our theoretical expectation of over 1 joule, our scaling calculations tell us that with higher current we can make it all the way to the 30,000 J that we need to demonstrate scientific feasibility. We’ve long concluded that this gap between theory and results is caused by the “early beam phenomenon” which is itself a symptom of the current sheath splitting in two, feeding only half its power into the plasmoid. In the next shot series, we will replace the washers with indium wire which has worked elsewhere on our electrodes to entirely eliminate even the tiniest arcing. We will also silver-plate the cathode rods as we have done with the anode. Over the longer run, we are looking at ways to have a single-piece cathode made out of tungsten or tungsten-copper in order to eliminate the rod-plate joint altogether. These steps should get rid of the filament disruption for good, enabling results to catch up with theory.



More Background

I just do not always cover all the background every time I update one of the projects that I am tracking. They are all available from the tags and by searching my site.

Dozens of articles on Fusion going back about 8 years.

My articles for more background on the overall general fusion work
http://nextbigfuture.com/2009/09/general-fusion-will-leverage-computer.html


http://nextbigfuture.com/2009/07/general-fusion-technical-challenge-of.html


http://nextbigfuture.com/2008/12/general-fusion-video-and-pictures.html

http://nextbigfuture.com/2011/11/npr-interviews-michel-laberge-of.html

Tracking progress on General Fusion and other approaches

http://nextbigfuture.com/2011/10/general-fusion-getting-inspections-from.html

http://nextbigfuture.com/2011/08/progress-at-general-fusion.html

http://nextbigfuture.com/2011/08/helion-energy-general-fusion-and-tri.html

http://nextbigfuture.com/2011/06/helion-energy-and-general-fusion-in.html

http://nextbigfuture.com/2011/05/general-fusion-raises-more-money-and.html

http://nextbigfuture.com/2011/01/magnetized-target-fusion.html

http://nextbigfuture.com/2010/07/multiple-promising-nuclear-fusion.html

http://nextbigfuture.com/2010/03/cosmic-log-covers-iec-fusion-general.html

http://nextbigfuture.com/2010/01/summarizing-how-better-nuclear-fission.html


http://nextbigfuture.com/2009/07/general-fusion-raises-usd9-million.html


http://nextbigfuture.com/2009/06/general-fusion-was-awarded-c139-million.html

http://nextbigfuture.com/2009/03/general-fusion-research-update.html

http://nextbigfuture.com/2008/12/general-fusion-almost-has-second-round.html

http://nextbigfuture.com/2008/12/update-on-general-fusion-steam-punk.html

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