Nobody Died from the Fukushima Reactors

Ian Hutchinson is a nuclear engineer and plasma physicist at MIT. His department studies everything that happens in the nucleus: fission, the energy source of today's reactors, and fusion, the energy source of the sun and stars, which nobody yet knows how to turn into practical power. Plasma is the fourth state of matter, reached when a gas gets hot enough that electrons unbind from nuclei. Most of the universe is plasma. Stars are plasma because only in those very hot states do fusion reactions run.

Fission takes a heavy element such as uranium and breaks it up. Uranium-235 has 92 protons and enough neutrons that the nucleus holds 235 nucleons, the catch-all for protons and neutrons. Fusion does the opposite: it joins light nuclei. Hydrogen has one proton; deuterium adds a neutron; tritium adds two. Smash deuterium and tritium together and you get helium, plus a large release of energy. Per unit mass, both fission and fusion release about a million times more energy than burning coal, oil, or hydrogen with oxygen.

Fusion is hard for a simple electrostatic reason. Both nuclei are positively charged, so they repel. To get them close enough for the nuclear force to win, you need enormous impact energies, which means temperatures of tens of millions of degrees. Stars reach ignition: they produce more fusion heat than they lose, the way a bundle of sticks keeps burning after you take the match away. On Earth gravity is far too weak to hold that plasma. Hutchinson's career has been magnetic confinement: keep a star-hot gas together with fields, long enough for net energy.

You still need walls, but not to bottle the plasma. The walls keep the atmosphere out. Magnetic-confinement plasmas are about a million times thinner than room air, so any leak of ordinary gas ruins the reaction, and if the plasma touches the wall it cools instantly. Making a vacuum is industrial routine. What remains unsolved is isolating the plasma well enough that it can keep itself burning on its own reaction heat.

Tokamak is a Russian acronym for toroidal magnetic chamber: a doughnut with a hole down the middle, and a magnetic field inside. The workhorse design puts a very strong field the long way around the torus. Charged particles in a magnetic field gyrate around the field line, following a helical orbit like a spring. They can stream quickly along the field but they cannot easily cross it. If the field lines never leave the chamber, streaming along them does not mean escaping.

A straight field, the kind a bar magnet or a Helmholtz coil makes, always has ends. Particles would hit those ends and dump their energy. That is why the chamber is toroidal. A purely toroidal field is still not enough. Current has to run through the plasma itself so the field lines twist into larger helices. The detailed reason is technical, Hutchinson says, but the effect is simple: the single-particle orbits stay inside.

Energy arrives when deuterons and tritons, at something like 100 million degrees, collide and fuse. One product is an alpha particle, a helium nucleus, which is charged, stays in the doughnut, and hands its energy to the rest of the plasma. The other product is a neutron, which carries about four-fifths of the fusion energy, is not confined by the field, and must be caught in a surrounding blanket that drives a thermal engine. That is the loop: heat, fuse, self-heat with alphas, harvest neutrons.

Experiments have already produced a few tens of megawatts of fusion power for a few seconds. That is on the order of 10 megajoules, Hutchinson says, a few doughnuts' worth of energy — literal doughnuts. Tokamak confinement is now understood in enough detail to predict what a self-sustaining, nearly ignited machine would require. With magnetic fields that are already very strong but still limited, the machine has to be very big.

The world is building that machine in the south of France. ITER, the International Tokamak Experimental Reactor, is designed to reach a burning-plasma state and generate about 500 megawatts of fusion power for hundreds of seconds at a time. It will still be an experiment. It will not put electricity on the grid or run around the clock. Its job is to show whether the path works and what engineering remains.

The personal cost of that timeline is the part Hutchinson does not dress up. ITER was designed for 30 years, has been under construction for 10, and was not even due to start operating until about 2025. A burning fusion reaction comes later still. By then, he says, he will be well and truly retired, and he does not know whether he will be alive. Realizing that, years earlier, was a discouragement. It is not an argument against the research. Fusion is justified and should get more effort than it does. It is also not a magic bullet that solves society's energy problem — and neither, in his view, is any other source.

Fission, by contrast, turned out to be astonishingly easy. Within a few years of discovering it, people had built a reactor, during the Second World War. What is hard is getting the materials, which Hutchinson treats as fortunate, because those same materials are the proliferation problem. The United States still gets about 20 percent of its electricity from fission and is building two new plants; China and India are building much faster. Nuclear power is intrinsically free of CO2, and the waste volumes, he argues, are moderate enough that keeping them away from people is not especially difficult.

Hutchinson sorts fission's drawbacks into four bins. Fuel: known uranium can support worldwide fission for thousands of years, maybe not millions. Waste: fission products are highly radioactive and some are volatile; at Fukushima a fraction volatilized into a cloud of cesium-137 and strontium-90. After-heat: when you stop the chain reaction, the fission products keep generating heat. Proliferation: the technologies that produce and enrich fissile fuel can be turned toward a weapon.

Fukushima is the after-heat story in public. The reactors shut down safely the moment the earthquake hit. Then a tsunami many tens of meters high destroyed the grid feed, cooling stopped, and heat from reactors that were already off eventually caused the release. Fusion looks better on all four counts: longer-term fuel, radioactivity at least a hundred times lower, essentially no after-heat because there are no fission products cooking themselves, and no need for the fissile-fuel chain. The hard part of fusion is turning it on, not turning it off.

Then he gives the number that the title of this piece is built on. Nobody was killed by the Fukushima reactors — essentially zero — in a tsunami that killed between 15,000 and 20,000 people almost instantly. On the scale of risks, he thinks fission came out of that looking pretty good. That is not the popular picture. People are poor at estimating risk; they flinch at sharks and sleep through car accidents. Part of nuclear energy's public-relations problem is the word itself. Say nuclear, Hutchinson notes, and people do not think of a power plant. They think of a weapon.

The bombs dropped on Japan were pure fission weapons, enriched uranium or plutonium, their energy almost entirely from splitting heavy nuclei. It was understood early that combining a fission bomb with fusion would yield more energy per unit mass. That device was called the Super, or more simply a hydrogen bomb. Hutchinson has never held a security clearance and will not pretend to leak secrets; he is guessing from the physics. The sequence is a chemical implosion, then a fission explosion, then compression of hydrogen isotopes that sets off fusion in the middle. That chain is how you get multi-megaton yields. Fusion alone does not get you there in a weapon.

There is a research cousin that tries little fusion explosions without a surrounding fission blast. Inertial fusion, mostly studied in the weapons-lab complex because of the overlap, gives up on a steady tokamak. You take a small deuterium-tritium pellet, hit it from all sides with extremely powerful lasers, and compress it so hot and dense that the reactions finish before the pellet flies apart. The National Ignition Facility at Livermore, started in the late 1990s and operating since around 2010, was built to reach that pulsed ignition. It did not, Hutchinson says, and it does not look as if it will, though someone might yet find a better way. In principle the approach still seems possible.

Fridman, born in the Soviet Union, finds it exceptional that decades of nuclear weapons have not produced the destruction everyone feared. Hutchinson is extremely thankful and not sure he is surprised. Cooler heads prevailed at crucial moments, and mutually assured destruction has, in a strange way, restrained the great powers: there has been no world war since the 1940s, perhaps partly because of the weapons. He does not treat that as a guarantee. Humans, he says, are deeply flawed and sinful. He does not feel confident it will go on like this.

Asked what existential threat worries him most — weapons, pandemics, nanotechnology, killer robots — Hutchinson does not pick a sci-fi villain. He is not confident his children and grandchildren will enjoy the civilization he has. Collapse can be catastrophic or progressive, and he thinks the progressive path is already in motion if population keeps exploding. Treating the problem as mostly CO2, as if solving carbon lets the world run an ever-expanding economy, is in his view quite wrong. The planet has a finite carrying capacity.

He is as nervous about eight billion people as about a few million deaths from COVID-19. He knows that sounds callous; he calls it a sober assessment. Then he does the energy arithmetic he has thought about for a career. Stabilizing CO2 at an acceptable level requires cutting worldwide carbon emissions by at least a factor of ten. Western per-capita energy use, and therefore emissions, is more than ten times the world average. A future that is both sustainable and much less inequitable is equivalent to cutting Western CO2 not by ten but by a hundred — down to one percent of current levels.

Talk of switching to natural gas because it uses perhaps 60 percent of coal's carbon is, he says, complete nonsense. It does not scratch the surface. Much of that energy goes into producing food, so a hundredfold cut is not a matter of dimming lights. He doubts it is feasible without dramatic social change or a smaller population, which is still rising. Is there a technological solution? In short, no. Contraception already exists; the technology of population control is solved. The challenge is society and human choice, and the same is true of energy and pollution. Most of the big problems are not scientific.

That is why he thinks it is a terrible mistake, even at MIT, to give students the impression that technology will solve it all. Technology will make tremendous contributions and is worth working on. It is a disaster if you think it will solve all of our problems. The same overreach, applied to knowledge rather than gadgets, is what he wrote a book against.

Hutchinson did not grow up a Christian. He became one as an undergraduate at Cambridge, after two close friends who were Christians, and smart in the way he then measured smart, treated the faith as something that made sense. Western art and architecture from the fifteenth century on made Christianity look like the foundation of the culture, not a great evil. What convinced him were two things. The historical evidence for the resurrection of Jesus struck him as rather good — not a proof, not a scientific demonstration, but extremely good historical evidence. And Christianity presented itself as a personal relationship with God, made possible by Jesus, not as a moral theory.

God, for him, is none of the usual pictures: not a force, not a metaphor engine, not an infinitely powerful computer, not a bearded man on a cloud. All of those are entities inside the created world. The fundamental claim of Abrahamic monotheism is that God is the creator of it, which is what the first two chapters of Genesis are actually about. Finite minds still need images. Christians say God has revealed himself supremely in Jesus: if you have seen me, you have seen the Father. Scientists, for most of the last five centuries, have also claimed to see the hand of God in creation.

Scientism is the belief that science is all the real knowledge there is. In *Monopolizing Knowledge* Hutchinson argues that the West has grown so reliant on science that it puts aside other reliable ways of knowing. Science as we have built it leans on reproducibility, measurement, and mathematics. Those tools are powerful and they are not the whole of knowledge. His usual illustration is history. You cannot discover human history scientifically, because you cannot rerun it. History is full of unique events. Unique events are, by definition, not reproducible. In that thin sense, history is a story of miracles — uniqueness, not necessarily God — and science does not like that.

Atheism and scientism are not the same. Plenty of people who do not believe in God still honor history, sociology, economics, politics, philosophy, art history, language, and literature as real ways of knowing. What Hutchinson disputes is the aggressive atheism of this century, sometimes called new, whose arguments he finds mostly old and mostly scientistic. When they say there is no evidence for Christianity, they mean science does not prove it. He accepts that. It is not a problem for him, because he never thought science was all the knowledge there is. He still finds the historical evidence for the resurrection persuasive.

Faith, Hutchinson says, is badly misunderstood when it is treated as believing things that ain't true, or believing things that are not proven. There is a strand of belief in propositions. There is also trust: in a person, or in the reliability of a technology. And there is loyalty. He has faith in his wife and tries to act in faith toward her. Christianity, he argues, calls people far more to trust and loyalty than to believing unproven slogans. Critics of religion tend to emphasize only the first strand and stop.

Living with incomplete evidence is not a religious special case. On the drive over he nearly took a wrong turning; the navigation voice was late; he had to decide. Humans do that constantly. His Christian commitments did not force him into a kind of decision-making he would otherwise have avoided. He would have had to do it anyway. Humility about what we know is, he adds, a very Christian outlook, the kind of humility Jesus taught, and it is not the same as blind dogmatism.

Loyalty points outside the self. Fridman hears in that a contrast with existentialism and atheism sliding toward individualism. Hutchinson will not grant the implication: atheists can be loyal. The sharper question is where morality comes from. Loyalty and duty are related. Grounding morals in mere human relationships, he thinks, struggles to be absolute or persuasive. If there is nothing but other people, why not defraud your neighbor when it is good for you? The leftover answers look like pragmatism. Nietzsche saw the hole once God was dead, claimed there was no answer, could not live with that, and invented the Übermensch — a move Hutchinson calls unsuccessful, and a forerunner of later racist ideology. Christianity, for him, grounds moral compulsion in a transcendent God rather than in other people.

Fridman has played sports his whole life. The bond on a team is enormous; the ball is often silly. People will cling to a set of beliefs for the sake of holding them together, red team and blue team on Twitter included. Hutchinson thinks tribalism is everywhere, hard to bear in the United States at the moment, and fed by the internet and social media. It is also an old human trait.

The genius of Christianity, he says, is that it supersedes tribalism. The Hebrews first thought of Yahweh as their tribal deity, like the ones around them. Early in that history came the claim that he was the God who created the whole thing. If that is so, he is not just the God of the Hebrews, and not just the God of Americans. He is the God of everybody. At Pentecost in the New Testament, the disciples speak in other tongues and people from surrounding countries hear them in their own languages. Whether one takes that as factual or not, Hutchinson reads it as a statement that the faith claims to transcend culture. That is part of what he finds appealing.

Why is there suffering? Hutchinson has some answers and calls theodicy one of the toughest questions. Some aspects have no intellectual reply that will satisfy. When he lectures, he can be sure people in the room are ill, in pain, facing death, or watching family do the same. Nothing he can say will solve that agony. The only thing humans can do for one another then is to be there, alongside a friend, colleague, or family member. Try to give intellectual solutions and you become the comforters in the Book of Job, who brought Job no comfort. Sitting alongside him did. That is the meaning of compassion: to suffer alongside somebody.

The first Christian word about suffering, he says, should be that compassion is all that really counts, and that God has already acted that way. In the person of Jesus, God suffered with us, took suffering deadly seriously, and was willing to enter creation and die a horrible death on the cross. The philosophical question remains: if God is good and omnipotent, why not take the suffering away? Hutchinson's reply is the consistency of the world. Reproducible behavior is essential to the integrity of our lives; without it we would not exist. That consistency is what we now call the laws of nature.

If you want a different world, you have to show a design that keeps the integrity we need in order to exist, think, love, and be, and does it better. He does not think anyone has put that alternative on the table. He also does not think the pre-Fall world was a physical state without death. Death has been part of biology for billions of years; a deathless Eden is, for him, inconsistent with science as we know it. There is a perfection from which humans have fallen, but it is not a vanished physics in which nothing died.

Indefinite life extension is in vogue. Hutchinson finds transhumanism neither attractive nor feasible. He is of an age where mortality is more obvious than it once was. In a conceptual way he is afraid of many things; death does not keep him awake at night. Like most people he is more afraid of pain. His Christian outlook includes life beyond the grave, not in this universe, not in this body, and maybe not in this mind: resurrection, being with God, in a sense nobody really knows how to specify. Near-death experiences are not, for him, how you find out.

The aspirations of transhumanism look horrific. Being downloaded into a computer would be a nightmare, not a dream, because it discounts the integrity of bodies as well as minds. We are not disembodied minds. If such a download were possible, the thing in the computer would not be him. It is not possible, and it is a very long way from being possible. On artificial intelligence he asks for more modesty than the genre usually offers. Chess programs beat him and he stopped playing seriously; search engines outstrip any individual at retrieving knowledge. Whether that is intelligence in the older sense he leaves open. A sentient robot, like other intelligent life in the universe, is an interesting theological question he does not find pressing yet.

The Bible, he says, does not give a quasi-scientific account of consciousness. We do not even know what the mind is. The commonplace theory treats us as wetware, a decent analogy to digital computers, which is exactly what licenses the transhumanist download. Hutchinson doubts that. He thinks quantum mechanics is very likely important in the brain — contrary to many colleagues, in line with people like Roger Penrose — and if so the mind is not reducible to portable software. It is so connected to the hardware of the body that the two are inseparable.

It is philosophically ignorant, he adds, to talk as if a full physical-chemical account of the brain would make the mind vanish. Mind may be an emergent phenomenon of physics, chemistry, and biology, and it would still have to be encountered and taken seriously. He is not a substance dualist: he does not think mind is a thing inserted into the body. What is added, in Christian terms, is spirit, which takes us beyond this universe. Consciousness and mind are not necessarily that added thing. Present brain scans are miserable at the resolution we would need, even at the cellular level, and hopeless in time resolution compared with a thought. Science will get much further. The concepts of humanity, mind, religion, and consciousness will not vanish when it does.

The simulation hypothesis is fun, and movies have used it. Hutchinson rejects the *Matrix* picture of bodies in beds having their energy drained. A more interesting version — an intelligent creator who set up the universe, set it in motion, and sustains it — is almost the same thing Christians already say, down to the line in Hebrews about upholding all things by his word of power. In that concept the simulation and the universe are the same object, billions of light years across. The analogy breaks if you imagine the simulation running on a computer inside some other universe. Christian theology says God is not one of the entities in the universe, which is a different structure from a program on a machine.

Adam and Eve matter to him because the story says the relationship between humans and God has been broken by disobedience, and that restoring it is what Jesus came to do, partly on earth and fully in eternity. How literally to take the first chapters of Genesis is an important question that, he thinks, people get bogged down in. What you would have seen if you had been there is speculation, and not terribly important for Christian theology. Asked whether he wishes they had not eaten the fruit — a question that folds back into suffering — he says you will have to read *Paradise Lost*.

The meaning of his life, he says, is many things, all centered on relationships: with God, and with family, wife, parents, children, grandchildren. Those are places religious and non-religious people both find meaning. Faith in a creator who has a will for the world, and the idea that one's life might have some small significance in that plan, is an amazingly powerful idea. As a student, before he was a Christian, he read a philosophy book whose approximate title was the meaning of life. It said there is no meaning; you make one up as you go. That is still the predominant secular view. He no longer subscribes to it.

Love and loyalty, if he had to advise his children and grandchildren, look like yielding your will or desire to another, valuing others at least as highly as yourself. That is only the start. True love reaches a point where you feel compelled by the other. It sounds scary and is, he says, terrifically liberating. Love brings you into service. He quotes the Anglican prayer book on Jesus, whose service is perfect freedom: for Christians, serving God is what perfects freedom. Love is in part captivity, and in a paradoxical sense also an amazing freedom. "Love is freedom." The conversation that began with confining plasma ends there.