Why a reality TV star and a physicist are building a nuclear reactor in Milton Keynes

In an industrial unit in the home counties, the brains behind this ambitious privately-owned fusion project have their sights set on an unlikely goal.

By Simon Ingram
Published 20 Feb 2020, 18:14 GMT, Updated 28 Apr 2021, 20:29 BST
Richard Dinan and Dr James Lambert at work at Pulsar Fusion, Milton Keynes, August 2019.
Richard Dinan and Dr James Lambert at work at Pulsar Fusion, Milton Keynes, August 2019.
Photograph by Simon Ingram

AUGUST 2019. This facility isn’t marked on the industrial estate signage. Perhaps it's because it's new. Or more likely it's because, slid between the names of carpet tile suppliers and kitchen cabinet wholesalers, the premises of a prototype nuclear reactor would raise more than just eyebrows.

Within these unexpected surroundings, two men sit at a table in a large, largely empty and very white room scribbling notes, examining equipment and occasionally turning to look at an object in the corner that looks like a half-built movie prop. 

A bank of computer screens and desks face the object at a respectful distance. Everywhere on the floor of the sports-hall sized space are complicated cog-like discs flat-laid on bubblewrap, various hand tools, cans of WD-40. The attire of the two in charge of the operation isn't clip-boarded and quasi-surgical, but rather mechanics' gloves, jeans and scuffed Converse. It's like a cross between a scene from The X-Files and a garage.

Yet the ambition on show, and its many collateral concepts, are in the most literal sense lofty: the future of energy, technology that could save our species, the potential for interstellar travel and one of the greatest science-meets-technology enigmas of our age. Which begs the question: is this enterprise is as crackpot as it is seems on paper?  

"People always think, oh, it’s a weapon, it’s going to blow up. But [nuclear] is just a word. It doesn’t take a lot to explain the difference between fusion and fission.” Richard Dinan (left) of Pulsar Fusion explains some basics.

Photograph by Simon Ingram

One word nudges the tongue when considering the potential pitfalls of nuclear power in your neighbourhood: ‘Chernobyl.’ It's certainly the one you might hear if you were to doorstep a resident of, say, Milton Keynes – and tell them that just over those rooftops there, a company named Pulsar Fusion is manufacturing a prototype nuclear fusion reactor designed to create a plasma hotter than the surface of the sun.

It's an inflammatory collection of words – enough to get the neighbours talking, surely. But this is just the smallest of the challenges facing young entrepreneur and project originator Richard Dinan

“The word nuclear is a terrible word. And the world fusion is a fictional one,” says Dinan. “People always think, oh, it’s a weapon, it’s going to blow up. But it’s just a word. It doesn’t take a lot to explain the difference between fusion and fission. If our only messaging challenge is to tell people what fusion is...” he trails off, then grins. “Making people invest because we see opportunities here is a real challenge. Making people relax isn’t.”

So firstly, what is that difference? Simply, fission releases energy by splitting atoms; fusion does it by combining them. Nuclear fission, with its use of large quantities of enriched uranium and plutonium, has been demonised, weaponised and has the proven capacity to poison the planet if implemented badly. Nuclear fusion, relying on power derived from small quantities of naturally-occurring elements, has the potential to help to save it.

But fusion's promise of abundant, clean energy from zero carbon sources with little or no fallout has so far eluded efficient application. The science is there, but its usefulness remains enigmatic – hence, the science-circle witticism: 'fusion is the energy source of the future – and always will be.’    

Two robot arms are capable of manipulating parts of the reactor are controlled from a distance.
Pulsar is one of a new breed of small-scale nuclear startups working on the applications of fusion technology.
Richard and Dinan and James Lambert during “the drudgery of experimental physics.“ August 2019.
Photograph by Simon Ingram

The reactor in the room

On and off-paper, Dinan has something enigmatic about him, too. Tall, with shoulder length blonde hair which he's constantly swiping off his face, he shifts between drifty and soft-spoken to a rapid-fire focus when discussing this project's subject. His passion for fusion is clearly authentic, as is his easily-summoned knowledge of this complex field of physics – despite not actually being a physicist himself. So how does he describe what he does? "I tell people I'm an estate agent," he says, smiling. “It’s a bit of a conversation killer. There is no elevator pitch for fusion. You'd need a tall building." 

Dinan – despite as he modestly puts it knowing “a lot about a little,” the little being fusion – has a complicated role in this process. Out of the room with the nuclear reactor in it, it's perhaps hard to ignore his skirmish with tabloid fame on the reality show Made in Chelsea – but it's very easy to ignore inside it. He claims his eureka moment was purchasing a Gibeon meteorite in Namibia, a lump of iron, cobalt and phosphorous. This triggered a fascination culminating in 2014, when he dragged the rock into the office of Sir Steve Cowley, then the head of the UK Atomic Energy Authority to talk about fusion.   

Now with his own fusion startup, it's now Dinan's job – amongst many other things – to bridge the gap between his company's stakeholders, and what he calls the 'super physicists,' in whose field his reactor's footprint firmly sits.

Construction of the reactor requires components that, according to Dinan (left) are 'not B&Q items.'
Photograph by Simon Ingram

Future = fusion - fiction?

To assist him with the latter is his sole employee, James Lambert – who, with a PhD in Physics and Philosophy, has a career that's been “based around communicating science, or helping other companies make sense of it.” The pair make an intriguing couple act, and both Dinan and Lambert are admirably hands-on with what looks like a rather specialist task. Both are constantly tinkering with drills and screws, shaping things on lathes, examining metal discs with punctured holes and inscrutable pump-like objects that, Dinan says, ‘aren't exactly B&Q items.’ The immediate goal is to validate their design with, as per the vernacular of key fusion waypoints, ‘first plasma.’ 

Sat back at their table, Lambert explains a few principles around the process. “You learn at school that there are three states of mass: solid liquid and gas,” he explains. “But these are actually very rare in the universe. There is a fourth – plasma – and it’s actually the most abundant. The main release of energy into the universe is plasma in stars, fusing hydrogen into helium.” 

Plasma is like gas in that it moves in an unstructured manner. But it's unlike a gas in that its atoms are charged. This enables it to do things that gases can't, such as carry an electrical current, or be held in place by a magnetic field. Contain it in this manner and you can speed up the interactions between the atoms in a plasma by heating it up. The problem is, atoms that carry the same charge don't want to interact: they repel each other. So interaction must be encouraged by creating very high temperatures, therefore very high speeds. And close containment, to force collision. This collision causes a fusion between particles, which then releases kinetic energy: a fusion reaction.

The most compelling part of all of this is that the fuel for such a reaction usually involves two of the most abundant materials in existence: hydrogen and helium. It's commonly said that if energy from fusion was cracked, you could achieve the same energy turnover from a glass of seawater as you could from a barrel of oil – with the additional benefit of nothing being dug up and burned, with no carbon released, or toxic fallout created. Though of course, it isn't quite a simple as that. 

The 'star in a jar'

Nuclear fusion is probably science's most infamous elixir. It's an elegant idea: the ultimate natural energy, the most obvious incarnation of which has been powering the planet since the first chemical reactions twitched into life: the sun. 

“The amazing thing about the Sun is that it fuels itself,” says Colin Stuart, author of Rebel Star: Our Quest to Solve the Great Mysteries of the Sun. “Its sheer size means that the temperature and pressure deep in its core is so immense, every second it turns 4 million tonnes of its own hydrogen into sunshine. Even at that rate it still has enough fuel reserves to blaze for another five billion years. Unlike humans, it needs no external source of energy.”

The potential of replicating this is, of course, colossal. Unlimited clean energy from an abundant source, following the rules of the engine that powers life itself. Scientists have tried to harness the effects of this engine for decades. But the real prize is the schematic for creating a small-scale replica of it – for miniaturising the reactions that power its plasma and channelling it into homes, engines and craft. We all see plasma in action: it's in our TVs, our fluorescent lights, the aurora borealis. But nobody has used it productively as an energy source – created the much-coveted 'star in a jar,' and figured out how to do something useful with it. Not yet. Not quite.

“You learn at school that there are three states of mass, solid liquid and gas... But these are actually very rare in the universe. There is a fourth – plasma – and it’s actually the most abundant. ”

Dr James Lambert
A view of the solar chromosphere, or the layer of the Sun’s atmosphere. The grass-like features are caused by the Sun’s magnetic field sprouting from beneath the surface. This image was taken at NSF’s Dunn Solar Telescope.
Photograph by National Science Foundation

“We don’t have access to the kind of pressures you find deep inside a star like the Sun,” says Stuart. “So for us to copy the Sun here on Earth we have to ramp up the temperature instead. The Sun does it at 16 million degrees, but the lack of pressure means that our fusion machines need to operate at 100 million degrees.” Then there is the question of containment – keeping hold of the elements generating this colossal, energy-creating heat. Fusion reactors do this by using powerful electromagnetic fields to keep the plasma in check, and substitute the tremendous gravity that does the job in a star. Plasma is a highly turbulent entity, and any electromagnetic field up to containing it requires a huge currents to power it – which, if energy is the aim, rather negates the whole exercise.

“It is a bit like trying to hold a puddle of water,” continues Stuart. “It easily slips through your fingers. Coming up with a way to trap the hot material for long enough is one of the big obstacles to conquer if we want a fusion power plant one day.” 

An elemental issue

Due to what goes in to fusion, creating an adequate return on investment requires a whopping output of power. This isn't a problem for nuclear fusion: its power to fuel ratio is colossal. But there we hit problem number two. 

Hydrogen may be the poster fuel of fusion, but it's particular neutron-rich isotopes of the element that is required in order to encourage a profitable reaction. These are deuterium (2H) and tritium (3H) which combine to yield a 'DT' reaction – which requires the lowest temperature for effective fusion to occur. The reaction produces an atom of helium and a neutron, which hits and embeds into the wall of the reactor creating kinetic energy which can then be used to, for instance, drive a steam turbine. So far so good: but while deuterium is found in abundance in seawater, tritium is exceedingly rare and extremely expensive.

Tritium is also radioactive, but this is a relative term: uranium-235, for instance, has a half-life of 700 million years – whereas tritium's is a little over a decade. But due to its scarcity, a viable substitute must be found to react with deuterium for large-scale energy. It is possible to 'breed' tritium inside a nuclear fusion reactor using lithium-6. This is considered as the best option for wholesale fusion, as currently the only other alternative – Helium-3 – is no alternative at all, given that it is even rarer than tritium. Thanks to the action of cosmic rays, it's thought to be found in abundance on the moon, hence it is often mentioned in conversations concerning the mining of our celestial satellite. Which leads to problems three and four: scale, and cost.

A diagram showing the DT (deuterium-tritium) fusion reaction. With the addition of heat and containment, deuterium and tritium fuse, creating an atom of helium, a neutron – and a lot of kinetic energy. In contrast, fission achieves similar bursts of energy by splitting atoms.
Photograph by divgradcurl illustrations / Alamy

Science or application?

If Dinan and Lambert seem slightly detached from the inherent issues of tritium and Helium-3 availability, there's a reason. They're not here to find a solution to fusion's limitations as a global-scale clean energy source. What they're doing is applying achievable small-scale fusion into something rather more nimble.

“We see fusion as a sector, not just a reactor mission,” Dinan says, arguing that small companies like his can move as quickly as the science, leaving large-scale state-sponsored facilities to chew on the bigger questions – and deal with the necessarily lengthy timelines. The key case is a major international project to develop fusion technology, the £15 billion ITER, or the International Thermonuclear Experimental Reactor. The project was established in 1988, began construction in 2008, and aims to achieve first plasma in 2025 – and that's before a power station even breaks dirt. 

Another operation closer to home concerned with fusion energy is the JET project, based in Culham, Oxfordshire. Their aim is domestic energy. "We know how to do fusion, and we’ve produced fusion power,” says Chris Warrick of the UK Atomic Energy Authority – where JET is housed – in an email. “The challenge now is to scale up from our laboratory research to large fusion reactors. The UK has recently announced a plan to put a fusion reactor on the electricity grid by 2040, which could be a world first.” 

Richard Dinan, meanwhile, began constructing his prototype in early 2019 – with the aim of first plasma by the end of it. So if he's not looking to fuel our houses and streetlights, what's the aim? What will his plasma power?

“Fusion is very real and it’s happening, the technology is all around us – so we thought, where could webe best positioned?” he says. Nearby, Lambert compares a just-delivered piece of silvery equipment with another seemingly identical item, concluding his examination with a frown. Then Dinan says, with a grin: “We thought it would be more interesting to design a rocket.”   

The JET experimental fusion reactor at the Culham Centre for Fusion Energy, Oxfordshire. JET stands for Joint European Torus, the last word referencing the circular shape of the containment vessel. The project hopes to see a fusion power station on the UK's national grid by 2040.
Photograph by Dave Pattison, Alamy
"Fusion rockets are very under-studied – there's more that can be done in the near-term." Richard Dinan and the experimental rocket plasma reactor, August 2019.
Photograph by Simon Ingram

The need for speed

Dinan's objective is to create a plasma-powered engine with enough thrust to propel a spacecraft through a vacuum at hitherto unachievable speeds. The argon-powered design based on his prototype, he claims, has a possible speed of 100,000 mph. Scaling up the size of the thruster and increasing temperatures to nuclear fusion levels – producing what's known as a 'fast neutron' – that figure climbs to 500,000 mph, utilising a fuel exponentially more energy-dense than rocket fuel. 

Which means shorter travel times to the planets using lower payloads of fuel, and much longer operational periods. “Once you’re in space, you don’t want to be trying to get around with combustion engines,” says Dinan. “To get to space from tarmac, you need combustion – but once you’re out of the atmosphere, it’s all about speed. That device,” he points to the construction in the corner, “is set up for testing a rocket plasma, not an energy plasma.”

This form of compact fusion isn't concerned with large-scale energy supply – a field well-catered for by, as Dinan says “all our brilliant physicists and all the people you'd expect.” They're leaving that to the multi-billion pound monoliths building tokamaks, colossal superconductors and power station designs, along with the problems of dealing with excess heat, finding strong enough structural materials and designing maintenance systems. Meanwhile, these guys plan to be negotiating technology deals with aeronautics innovators with a working prototype small enough to fit in the back of a van.

So it's all about leaving the planet, rather than saving it? “When it comes to fusion, governments have said ‘energy, energy, energy’. Very few private companies have got the funding to do fusion – and the ones that have just followed, and said ‘energy energy energy.’” Dinan says. “So yes, if you can get a fusion burn, you can build a steam turbine around it, and plug it into the power grid, which may take 10 years, and is already being done by all these other companies. Or you can become the first put one of these devices in space. Fusion rockets are very under-studied. There's more that can be done in the near term.” 

Dinan is quick to acknowledge that “a fusion power station would be the end-game of energy” – but believes propulsion is a “natural first step” towards the domestic energy elixir. It's clear, though, that his own head lies in the heavens as far as this project is concerned. 

“We’re either this cancerous little species that just sits on the planet and consumes all its resources, or we are a species that is destined to transition into the stars. And if we are ever going to leave our solar system, we need fusion. We aren’t going to get to Alpha Centauri by setting things on fire.”

Now operational, Dinan and Lambert examine the interior of their reactor, and the prototype thruster, February 2020.
Photograph by Simon Ingram

FEBRUARY 2020. It's winter, and Pulsar Fusion is filled with the sound of industrial heaters – as well as a different kind of buzz amidst its two permanent employees. In its corner, the reactor prototype has gained a considerable amount of paraphernalia: a large wooden scaffold, an electromagnetic rig, a complicated looking wiring loom. And it's also gained something else: status. It's now working. 

“We cooked some parts,” Richard Dinan says, smiling. “Broke some stuff. But a resounding success for the company as far as technological achievement goes, if I don't say so myself.”

The critical event itself perhaps requires some explaining to anyone unfamiliar with plasma thruster tests: a circular glow builds to brilliant pink, then ebbs, then builds, fed by something angled off its orbit that looks like a miniature blowtorch. 

"What you are seeing is plasma being ejected from this cathode,” explains James Lambert, indicating the ‘miniature blowtorch’ in the exposed innards of the reactor. “That's then being captured in this channel here, by in the magnetic field created by this coil.” He indicates a white cylinder with a groove running around that looks like a piece from an electric drum kit. "This is actually entirely iron,” Lambert says. “The white stuff is just a heat shield to protect it from the temperature of the plasma.”

The argon fusion thruster exposed, and during tests. The purple glow is caused by the presence of argon as a propellant: similar thrusters on test on the USA use xenon, and glow blue.
Photograph by Simon Ingram, Pulsar Fusion centre

So how does it work? Lambert explains: “This device is really just a heated object. You heat it up to about 1,500 degrees C, just using an electric current.” In this prototype, argon gas is then injected the back of it, and it gets heated to plasma temperatures. That's when the electrons get pulled away from the atoms. “These electrons get trapped in the magnetic field, and it's this accumulation of electrons that accelerates charged particles from the back of the engine forwards, then out – and down into the base of the vacuum chamber.” This, as Lambert's hand gestures suggest, equals thrust.

“The speed of it coming out is super, super quick. About 20km a second,” adds Dinan.  

The device is modelled on a Hall thruster, an engine “originally designed for delicate re-adjustments of satellite orbits, and tend to generate only a small amount of thrust,” Lambert says. The vacuum chamber serves two functions: to simulate space conditions, and to avoid the problematic combustibility of oxygen. So this type of engine only works in a vacuum, but once there, it works very well. 

Electrical Hall thrusters, such as NASA's X3, are being tested using electrical power. Existing plasma thrusters are low-power, therefore would need to burn for a long time before any meaningful mission distances are achieved, posing durability challenges given the heat involved. And solar power can't be relied on if deep space is on the agenda: the Voyager spacecraft, so far the furthest human-made objects from Earth, generate their modest 470 watts of electricity from plutonium. 

The addition of a nuclear fusion reaction to this design – thereby cranking up the heat, and thrust speeds – increases its potential for accelerating a spacecraft in the vacuum of space. “Our whole pitch as a business is to repurpose this technology, take this ejected plasma, and heat it up to fusion temperatures.” Lambert says. “We can then use that enormous increase in temperature to turn it into a powerful spacecraft engine that can then be used for travelling from earth, to the planets – or whatever your mission happens to be.”  

The occasionally rather beautiful signatures of high heat on components in the Pulsar Fusion unit, February 2020.
Photograph by Simon Ingram

Bigger, hotter, faster, further

Following the successful test of its prototype, the next step for Pulsar Fusion is simple. “We're making a bigger one,” Dinan says. Which is where things start getting rather more serious. Bigger thrusters means hotter plasma, which means nuclear fusion power. And – inevitably – bigger premises.

So coming back to the C-word, what if it all goes wrong? Lambert smiles patiently, Dinan perhaps a little wearily. “You know, people always used to say they were going in for an NMR scan – nuclear magnetic resonance imaging,” he says. “Now we call it MRI. They changed it because again, people don’t like the word ‘nuclear’.”

Richard Dinan and his prototype reactor, February 2020.

Photograph by Simon Ingram

“If we are ever going to leave our solar system, we need fusion. We aren’t going to get to Alpha Centauri by setting things on fire.”

Richard Dinan

“A Chernobyl-style meltdown just isn’t possible with fusion,” says Chris Warrick of the UK Atomic Energy Authority.

“With nuclear fission, the reaction happens very easily and naturally accelerates; so [you're] moderating a potential chain reaction. In fusion we have the opposite problem – getting reactions started and keeping them going is very difficult. But this gives us an inherently safe process, because if a fault develops when running a reactor the plant shuts down almost instantly.”

Dinan is more direct: “If you were to attack the reactor with an axe, you'd lose your reaction and get a little puff of tritium. And that's it.” That, and presumably, a rather large bill.

But however lofty the ambitions of Pulsar, spend any time investigating the concepts involved in fusion and it's entirely believable that in this dynamic enclave of science, the next big idea could well emerge from a startup like this.

And considering the roadmap involved in large scale fusion energy projects, the concept of a fusion-powered space engine arriving before a power station doesn't sound that unlikely at all. “There’s something mysterious and exciting about exploring a new technology,” Richard Dinan says – before adding, with a grin: “it's not like it's rocket science.”  

What is Nuclear Energy?
How does nuclear energy work? Is radiation a risk? Find out the difference between nuclear fission and fusion, how uranium fuels the process, and the pros and cons of this alternative energy source.

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