Archive for April, 2013

Helion Fusion Engine Artist Rend

Fancy bow tie. Helion’s Fusion Engine fires plasmoids of deuterium and tritium at each other from either   end. They collide and fuse in the middle, giving off direct electricity as well as heat captured by a coolant that could be FLiBe.

The paradox of fusion energy is that it is always 40 years away, and has been for some 60 years.

So scoff the fusion skeptics. And if you look at the projected timelines of the large intergovernmental fusion projects like ITER in France and NIF in California, you could easily join the ranks of those not holding their breath.

But as I’ve written here before, there are a number of smaller and privately-backed fusion initiatives that could solve the fusion riddle long before the ITERs or NIFs do.

One of those companies is Helion Energy, a Redmond, Washington-based company that claims it will build a 50-MWe pilot of its “Fusion Engine” by 2019 after which licensees will begin building commercial models by 2022. That’s hardly the 40-year odyssey we’ve long heard about.

Helion will obviously have to overcome many challenges in order to take the express lane to fusion land. I won’t write about all of them in this post.

But what strikes me as particularly relevant to Weinberg readers is how Helion (and the fusion community in general) is facing materials challenges and decisions that are similar to those confronting developers of alternative fission technologies like fast reactors and molten salt reactors (MSRs).

For example, Helion is contemplating the use of FLiBe – the molten salt that’s part of MSR designs – as a coolant and an electrical insulator. It’s also examining the abilities of different metals to withstand ferocious neutron bombardment – just the sort of thing that many fission researchers are also investigating as they try to move away from conventional fission reactors and to higher temperature and other alternatives.

FUSION’S PROMISE

Before I dive in to Helion, and in case anyone needs a refresher:  Fusion joins atoms together rather than splits them apart as fission does. Many experts regard its as the Holy Grail of energy sources, noting among reasons that fusion does not leave long-lived high-level waste; that it requires comparatively little fuel and its fuel is to a large extent easy to obtain and plentiful; and that it cannot meltdown (even if it does require temperatures of over 100 million degrees C) and leak harmful radioactivity. (It also creates helium, a substance with many uses but one that is in increasingly short supply).

“Fusion has the potential to provide nearly limitless, clean energy for both baseload and on-demand power,” notes David Kirtley, Helion’s interim CEO, who I spoke with via Skype recently. “Fusion fuels are inexpensive, sustainable and can be supplied with minimal environmental footprint.

Helion FusionExperiment

Don’t try this at home. Helion has built and tested an experimental version of the engine, without the    coolant and heat exchanger.

Helion’s small “Fusion Engine” uses principles of magnetism to generate heat that induces istopes of hydrogen to fuse. But it bears little visual resemblance to the giant 20-story “tokamak” that ITER is building in Cadarahce, France using different techniques of magnetism.

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 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.

IN AND OUT

The overarching problem that Helion, ITER, NIF, and others are working to solve is that the amount of energy it takes to coax sustainable fusion reactions is greater than what can be harnessed from the reactions.

When you consider that temperatures inside many fusion designs hit 150 million degrees C, albeit briefly, then you can start to appreciate the amount of energy required to get things cooking. In Helion’s case, it is powering capacitors that convert the deuterium and tritium gas into plasmoids. It is also powering electromagnets that surround the narrowing cylinders through which the plasmoids shoot. The pulsing magnets induce the plasmoid to accelerate.

A fusion chamber also requires durable materials – doubly so since neutrons bombard the inside walls, severely testing their durability (except for in a process called “aneutronic fusion,” but more on that another time). Therein lies one of the main crossover points between fission and fusion development. Both are looking for materials that can handle high energy neutron bombardment and high temperatures. Although fusion has a kinder brand image than does fission, the fact is that it sets neutrons racing about just as fission does (again, aneutronic fusion does not do this).

For Helion, this means finding the right material to line the inside of the compression chamber where the plasmoids collide and release neutrons.

“This wall is exposed to high levels of radiation and high thermal load,” notes Kirtley. Helion is considering alloys including tungsten, beryllia and molybdenum. These materials will be familiar to engineers and scientists working on high temperature fission reactors. As Kirtley notes, “the tungsten alloy claddings in high-temperature reactors absolutely share material crossover.” Helion’s collaborators on so-called “first wall” development include the U.S. Department of Defense and the University of Washington, he says.

JohnSlough RedmondReporter

A man of two fusions. Helion co-founder John Slough and his company MSNW are designing a separate fusion reactor, called the Fusion Driven Rocket, meant for spacecraft propulsion.

As important as durability is, Helion has another ace up its sleeve. It has devised a technique that allows for “rapid replacement” of the wall, a breakthrough that Kirtley describes as “one of the key advantages” of the Fusion Engine. “We believe it is key to the engineering design of an economically feasible fusion energy system,” he says.

In Helion’s Fusion Engine, a coolant material will form a blanket that absorbs the neutrons and their heat after the neutrons escape through the wall. As is the case with some fission research companies, Helion is not yet sure what coolant it will use, although its preference is FLiBe – a molten salt of lithium fluoride and beryllium fluoride. The MSR reactor community will recognize FLiBe as one of the fluids that can serve as both a coolant blanket and a fuel carrier in an MSR. It is the substance that lends its name to Flibe Energy, the Hunstville, Ala. company that is developing a two-fluid FLiBe-based MSR.

Helion is also considering using lithium as the blanket coolant. Lithium is a common choice in fusion designs because it reacts with the neutrons to make tritium. Of the two hydrogen istopes commonly used in fusion – deuterium and tritium – tritium is the more difficult to obtain (deuterium is found commonly in seawater), so a process that replenishes tritium via interaction with lithium is a popular design among fusion engineers. Kirtley claims that Helion’s fusion process requires less tritium than do other fusion technologies and that the Fusion Engine makes some of its required tritium by fusing deuterium atoms in the collision.

“Our reactor design removes the majority of the complex tritium producing blanket,” says Kirtley.

Thus Helion has less need to breed tritium from lithium and it is therefore looking seriously at FLiBe, which is a more effective, less expensive and less problematic coolant than lithium, he notes.

FLiBe’S FUSION HISTORY

The idea of using FLiBe as a fusion coolant is not new. The U.S. Department of Energy’s Idaho National Laboratory has investigated it in partnership with Lockheed Martin, the aerospace stalwart that is also developing a fusion reactor.  Likewise, Ralph Moir, the physicist known for his interest in hybrid fission/fusion reactors , published a paper on a fusion FLiBe coolant over 20 years ago at Lawrence Livermore National Laboratory in which he notes that FLiBe avoids the fire hazards of lithium as a fusion coolant. MIT and Argonne National Laboratory published separate papers on FLiBe and lithium’s usefulness in fusion reactors in the 1970s.

FLiBe might serve a second purpose on Helion’s Fusion Engine as well. Kirtley says the company wants to use it to provide electrical insulation to the electromagnets. By using FLiBe for that function as well as for the coolant blanket, Helion would simplify its materials needs and lower its costs, he notes.

Helion’s design comes from company co-founder John Slough, who is also a research associate professor at the University of Washington and who runs Redmond-based space propulsion firm MSNW LLC.

Slough is a fusion enthusiast, to say the least. He is designing a separate fusion reactor intended as a propulsion device that in principle could send manned spacecraft to Mars in 30 days. That project known as the Fusion Driven Rocket, has funding from the U.S. National Aeronautics and Space Administration.

The more earthly Fusion Engine has received about $7 million in funds from DOE, the Department of Defense and NASA. The company hopes to raise another $2 million by next year, $35 million in 2015-17, and $200 million for its pilot plant stage.

It will compete for development funds with other fusion initiatives, such as those at General Fusion, Lockheed Martin and the “aneutronic fusion” projects at Lawrenceville Plasma Physics and Tri-Alpha Energy. It will also compete against fission development. But given some of the material similarities with fission, it might also find itself in collaboration with some of those efforts.

Images provided by Helion. Photo of John Slough from Redmond Reporter via Helion. 

Liquid fission: The best thing since sliced bread?

Posted by Mark Halper on April 22nd, 2013

Written by guest blogger John Laurie 

OttoRohwedder Historical-Nonfiction Tumblr

What do the two men above have in common?

Give up?

Well, they both made great contributions to humanity by proposing a change to the established order in which things are done.

The man on the left was the first to say “Hey, why don’t we cut the bread BEFORE we sell it?”

The man on the right was the first to say “Hey, why don’t we have the meltdown BEFORE we put the fuel in the nuclear reactor?”

In 1927 Otto Frederick Rohwedder successfully designed a machine that not only sliced the bread but wrapped it. Missouri’s Chillicothe Baking Company installed his first machine, and the first loaf of sliced bread was sold commercially on July 7, 1928. Sales of the machine to other bakeries increased and sliced bread soon became available across the USA.

Alvin Weinberg and his team at the Oak Ridge National Laboratory (ORNL) pioneered liquid fission, building and operating the world’s first nuclear reactors to use a liquid fuel composed of molten fluoride salts.

The Molten Salt Reactor Experiment ran successfully at ORNL from 1965 to 1969. Raw materials were prepared using a meltdown furnace, then allowed to cool before being shipped to the reactor site for re-melting and transfer into the drain tanks of the reactor. The word “meltdown”, which has become synonymous with major accidents in solid fuelled reactors, describes a completely normal and safe process in liquid fission.

The ORNL team proved that this technology could be cheaper, safer, more efficient and generate far less waste than solid fuelled reactors, only to see their funding cancelled and the team disbanded, mainly for political reasons.

But advocates of liquid fission should take heart from the story of sliced bread. Rohwedder originally began working on the bread-slicing machine concept in the 1910s. Unfortunately a fire in 1917 destroyed the factory that was to produce the invention, and the original blueprints. It took him 10 years to recreate his invention.

It’s been over 40 years since Alvin Weinberg built his liquid fission machine.  Now a new crop of researchers are picking up where he left off. It’s time for his idea to flow.

John Laurie is a bilingual design engineer who found out about liquid fission last year. He has a web site called Energie du Thorium which brings information and news on thorium and molten salt reactors to a French speaking audience.

OakRidge MSRE Welding

Welding past, present and future. David LeBlanc will combine features from Oak Ridge’s 1960s molten     salt reactor with the SmAHTR concept, to make his own “Integral Molten Salt Reactor.” That’s not LeBlanc above. It’s a welder finishing up the Oak Ridge MSR over 40 years ago.

The more I watch developments in the molten salt reactor field, the more impressed I am by the variety of innovative approaches.

While every molten salt reactor project I’ve encountered traces its inspiration and probably its basic design to the 1960s Oak Ridge National Laboratory project in Tennessee, the number of modifications that different labs are pursuing is starting to resemble the type of competitive differentiation that defines a free market.

Before I get too carried away, let me acknowledge that MSRs are a long way from the market (although with the right breaks, not as long as some would believe). Thus, it’s admittedly premature to compare them to the thriving technological leapfrogging of, say, the automobile or information technology industries.

But MSR companies nevertheless are in the early stages of trying to one-up each other as they all chase the general goal of building a reactor that runs on liquid fuel rather than on conventional solid fuel, and that provides a host of improvements in safety, efficiency and long-lived waste reduction.

The most recent case in point comes from the newest of the statups: Terrestrial Energy Inc., based in Ottawa Canada, and run by co-founder, president and chief technology officer David LeBlanc.

Dr. LeBlanc is an MSR expert who in January wrote a guest blog here in which he pointed out among other things that it would be in the best interest of the MSR industry to keep designs as simple as possible in order to stand a chance of commercializing within a reasonable time frame.

That advice struck me as sensible, so I made a point of following up with LeBlanc, who incorporated Terrestrial in late 2012 after several years of running an MSR intellectual property company called Ottawa Valley Research Associates.

We spoke by Skype last week, when LeBlanc explained the pragmatic reasoning behind his simplicity push, noting that, “You cannot underestimate the cost of nuclear R&D.”

BURN DON’T BREED

He outlined his plan for simplicity. In keeping with the theme, let me attempt to keep it simple:  Terrestrial Energy is departing from the original Oak Ridge scheme that called for a two-fluid molten salt reactor that would breed its own fuel.  Instead, Terrestrial’s design calls for a single fluid reactor that would “burn” rather than breed. In the nuclear lexicon, LeBlanc’s reactor is known as a “burner” or a “converter”, not a “breeder.”

While a two-fluid breeder would be the “Ferrari” of MSRs, the world cannot afford to wait for its development, given the desperate need for CO2-free energy sources such as MSRs, notes LeBlanc.

Dual fluid breeder MSRs face a number of extra challenges that will prolong their development beyond that of a single fluid MSR. Among them:

  • The infamous “plumbing problem” that vexed Oak Ridge. In a two-fluid design, one fluid continuously breeds fuel, feeding it into another fluid where the nuclear reaction takes place. The pipes and materials that house and separate the fluids are subject to damaging wear and tear.
  • Dual fluid breeders require constant removal of fission products, which are the short-lived radioactive waste products of a nuclear reaction (different from the long-lived “actinide” wastes like plutonium) “That requires a lot of R&D and a lot of capital to develop,” notes LeBlanc, who points out that in the 1960s, Oak Ridge had planned to remove fission products on a 10-day cycle by removing a tenth of the salt each day.

Ergo, LeBlanc’s single fluid approach, which uses denatured uranium – low enriched uranium that is useless for weapons fabrication.

Compared to a breeder MSR, a burner based on denatured uranium has the obvious disadvantage of not running forever on its bred fuel. LeBlanc downplays that, noting a once-through cycle can last for up to 30 years in a single fluid MSR. In addition, the actinides – which are much less than in conventional reactor waste – could potentially be removed at that point and recycled into the next fuel batch, minimizing long-term waste storage needs.

DIAGRAM IMSRvsModularsvsBeetle2 2

Packing a punch. LeBlanc’s high power density design means that his IMSR can be smaller than other modular reactors. Above, he compares a 25 MWe and 300 MWe version of the IMSR to the SmAHTR design, and to more conventional modular reactors from Nuscale and Babcock & Wilcox. He borrows from a famous VW ad slogan. Spot the Beetle – it’s to scale.

Those 30 years, though, would require annual top-ups of uranium. But as LeBlanc points out, the amount would be only about one sixth of the uranium requirements for today’s conventional solid fuel reactors.

Toward the end of its molten salt reactor days, Oak Ridge designed and built a single fluid MSR to run on denatured uranium, along with thorium, called a DMSR.

GET SMAHT

Terrestrial Energy is drawing on that design, but is combining it with principles borrowed from another technology called SmAHTR, for Small Modular Advanced High Temperature Reactor.

The 50-megawatt (electric) SmAHTR is a conceptual innovation at Oak Ridge. It is a small version of the liquid cooled 1500 MWe AHTR  – on which Oak Ridge is collaborating with China  – that places the heat exchange inside the reactor vessel.

SmAHTR and AHTR introduce liquid cooling (molten salts) to high temperature next generation solid fuel reactors such as those that use TRISO fuel – pebble bed reactors – and those that use prismatic blocks where the fuel is embedded in graphite blocks that serve as the moderator. Those reactor designs have in the past typically used helium gas as a coolant, which presents various mechanical difficulties and requires high pressure.

LeBlanc believes that by switching the fuel into the molten salt, it offers many benefits of liquid fuel while retaining innovative features of the SmAHTR design. One such benefit: The reactor generates heat directly in the liquid fuel, which permits higher power density operation. Placing the heat exchanger inside the reactor vessel rather than outside – as with some other MSRs – helps.

That, in turn, will allow Terrestrial to build smaller but equally powerful reactors compared to other small modular manufacturers that are using more conventional solid fuel, water-cooled designs, such as Babcock & Wilcox (see diagram above).

NAME THAT REACTOR

Not to be outdone on the nomenclature front, and in keeping with the MSR industry’s nascent differentiation trend, Terrestrial gives its reactor a unique name: the Integral Molten Salt Reactor, or IMSR.

The IMSR will also include patent pending innovations, on which LeBlanc declines to publicly elaborate.

Another IMSR feature: It will use a core of graphite moderator slabs between which the fuel flows which LeBlanc says, “allows other advantages like tricks to limit the amount of neutrons reaching the vessel wall.” This addresses a problem that developers of liquid fuel fast reactors will find difficult to crack, he notes.

With the right combination of power density and core design Terrestrial could build the IMSR with upwards of six times the electrical output of the same size vessel as SmAHTR. It would require replacing the graphite core every four years. The fuel would reside temporarily in a holding tank during the core swap. That marks an improvement over the SmAHTR concept, which requires a swap of the solid fuel core every four years.

LeBlanc envisions IMSR reactor sizes ranging from 25 MWe to 300 MWe.

As with other MSR startups, such as the Japanese single fluid company Thorium Tech Solution, LeBlanc is undecided on exactly what salt he’ll use.  While FLiBe salt (lithium fluoride and beryllium fluoride) is commonly associated with dual fluid MSRs, its lithium isotope is problematic, for reasons I’ll examine in a subsequent blog.

LeBlanc says he is considering alternatives including sodium based salts.

In the long run, he has not ruled out a breeder design or thorium fuel, but for now, he’s focused on the single fluid uranium reactor.

“The burner is less challenging than the breeder,” notes LeBlanc. “It greatly reduces technological and regulatory hurdles.”

His goal is to commercialize the Terrestrial reactor by 2021. With his simple and SmAHTR combination, he stands a reasonable chance.

Photo from Oak Ridge National Laboratory. Diagram from David LeBlanc. 

Geoff Parks Horse

Riding the thorium trail. Cambridge senior lecturer Geoff Parks believes actinides could recycle for a long, long time when mixed with thorium in a modified light water reactor.

Thorium mixed with plutonium and other actinide “waste” could continuously power modified conventional reactors almost forever in a reusable fuel cycle, according to a discovery at the University of Cambridge in England.

The discovery, by PhD candidate Ben Lindley working under senior lecturer Geoff Parks, suggests that mixed thorium fuel would outperform mixed uranium fuel, which lasts only for one or two fuel cycles rather than for the “indefinite” duration of the thorium mix.

Ideally, the reactors would be “reduced-moderation water” reactors that work on the same solid-fuel, water-cooled principles of conventional reactors but that do not slow down neutrons as much and thus also offer some of the advantages of fast reactors.

Lindley’s finding, made while he was a master’s candidate in 2011, bodes well for the use of thorium not only as a safe, efficient and clean power source, but also as one that addresses the vexing problem of what to do with nuclear waste from the 430-some conventional light water reactors that make up almost all of the commercial power reactors operating in the world today and that run on uranium.

By mixing thorium with “waste” in a solid fuel, the nuclear industry could eliminate the need to bury long-lived plutonium and other actinides.

Lindley’s work surfaced recently in an article about it in the hard copy edition of Cambridge’s quarterly Engineering Department magazine. An earlier version also appears online.

ACCENTUATE THE NEGATIVE

I interviewed Lindley and Parks recently after the magazine story appeared. They explained the crux of Lindley’s discovery: Uranium/plutonium lasts for only a limited period because after one or two cycles, when the actinide portion increases, the mix displays a “positive feedback coefficient.” In the sometimes counter intuitive world of nuclear engineering, a positive feedback is an undesirable occurrence. To use an unscientific term, the reaction goes haywire.

Parks notes that with uranium, “As the amount of actinides in the mixture increases, you get this tipping point where with the uranium mixed with actinide based fuel  – a key feedback coefficient goes from being negative to being positive, at which point the fuel is not safe to use in the reactor.”

Lindley completes the thought. “The idea is that mixing things with thorium rather than with uranium keeps the feedback coefficient negative,” he says.

In a mixed fuel system, reactor operators would allow a batch of fuel rods to stay in a reactor for about five years, roughly the same as with today’s solid uranium fuel. The fuel would then cool for a few years while the shorter-lived fission products decay, and would then be reprocessed over another year, mixing actinide wastes with more thorium before being put back in a reactor.

And just how long could this cycle continue? “You could just keep doing that forever – until the world runs out of thorium,” notes Parks.

Ben Lindley

Wasting his future. Cambridge PhD candidate Ben Lindley made the discovery that actinide waste will     burn with thorium for an indefinite period, auguring a way to simultaneously generate power and dispose   of nuclear waste.

Lindley’s proposal is the latest possibility to emerge for using thorium reactors to dispose of waste as well as generate power.

As we wrote here recently, Japan’s Thorium Technology Solution (TTS) is proposing to mix thorium and plutonium in a liquid molten salt reactor.  Likewise, Transatomic Power in the U.S. has similar plans, although it is starting first with a liquid mixed uranium fuel rather than with thorium.

Lindley and Parks’ idea differs from TTS and Transatomic in one obvious way: It would allow the nuclear industry to carry on building conventional solid fuel, water-cooled designs. That would be strictly true only in the initial implementation of the technology, which Lindley and Parks say would entail thorium mixed only with plutonium rather than also with other actinides like neptunium, americium and curium. That’s because plutonium is now available from sources such as the Sellafield nuclear waste site in Britain. The other actinides are not as readily available, but would become so as it became clear they could be used as part of a mixed thorium fuel, Lindley and Parks believe.

GO EASY ON THE WATER

Once the other actinides enter the mix, the optimal reactor would be a light water reactor modified to have less water and thus less moderation of neutrons in the reaction process. That, in turn, would allow more burn up of actinides.

Lindley envisions a reactor with about a quarter to half the amount of water as in a conventional LWR – enough to serve as a necessary coolant, but little enough so that the water could not slow down neutrons to the extent they do in a conventional reactor.

“It’s not really a fast reactor, and it’s not really a thermal (conventional) reactor,” notes Lindley. “It’s between the two.”

Hitachi, Toshiba, Mitsubishi Heavy Industries and the Japan Atomic Energy Agency all have reduced-moderation water reactor designs (RMWR), according to the International Atomic Energy Agency.

Lindley described them as similar to LWRs but with different fuel assemblies.

The development – and regulatory approval – of RMWRs is one of several challenges facing the deployment of mixed thorium fuel in a water-cooled reactor.

Another is the development and cost of reprocessing techniques for thorium and for actinides other than plutonium (for which reprocessing already exists).

“Splitting thorium from waste or splitting some of the minor actinides from waste has not been done on an industrial scale,” notes Lindley. “There are processes that are envisaged that can do that, that have been tested on a laboratory scale, but never on an industrial scale.”

Another hurdle: Fabricating fuel that as Lindley notes would be “highly radioactive” given the amount of waste that would go into it. “That would have to be done behind a shield,” Lindley says.

Reduced Moderation Water Reactor JAEA

“Light water Lite.” Lindley’s proposal to mix thorium with plutonium and other actinides would work best in   a reduced-moderation water reactor. The diagram above shows a uranium version of an RMWR, from the Japan Atomic Energy Agency.

All of that will require significant research and development funding –more than what Lindley currently has at his disposal, which consists of university research funds and academic scholarships.  One possible source for additional funding could be Cambridge Enterprise, a commercial arm of the university.

U.S. nuclear company Westinghouse has also been collaborating with Lindley on his thorium research. Lindley hopes to test his fuel at the Halden test reactor in Norway, where Westinghouse is a partner in Thor Energy’s project to irradiate thorium/plutonium fuel.

It will be interesting to see if any of the £15 million that the UK government recently earmarked for nuclear R&D finds it way to Lindley’s project. It’s possible that Sellafield could at least provide plutonium.

FUNDS FROM DECOMMISSIONING?

Given the potential usefulness of thorium as a way of ridding the UK of actinides, it’s not out of the question that funding could also come from the UK’s Nuclear Decommissioning Authority, which has a 2013-14 budget of £3.2 billion and which is responsible for managing nuclear waste, including actinides and shorter lived fission products.

As Parks notes, an ultimate goal for applying Lindley’s discovery “is to come up with a nuclear fuel cycle where the only waste you have to dispose of  is the fission product waste.”

Parks encourages the government to “grasp the nettle” and financially back the thorium research. He and Lindley note that a multiple-cycle thorium reactor would save money in the long run for among other reasons: uranium prices, although low now, will rise; and a mixed thorium/actinide fuel would eliminate costs associated with nuclear waste storage.

“There are economic benefits in the future to investing in the reprocessing and fuel fabrication aspects now,” says Parks. “And you would completely change what nuclear waste means as far as the public is concerned, in terms of the volume of it and how long it’s radioactive for.”

Lindley and Parks say that their technology could take hold in a commercial RMWR within 10-to-20 years.

For that to happen, they’ll have to find the right mix of collaborators and financial backers.

Photos from Geoff Parks and Ben Lindley. RMWR diagram from Japan Atomic Energy Agency

 

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