nuclear fusion

nuclear fusion

The facts about nuclear fusion don’t support the hype around it that followed the recent “breakthrough”, as many media echoed it. However exciting the present results may be for scientists, nuclear fusion will not contribute to solving the current energy crisis. It will only drain more funds and absorb more energy for which we have better use. Those are not prognoses. Those are facts.

The achievement of fusion ignition at Lawrence Livermore National Laboratory (LLNL) was announced as a major scientific breakthrough that will pave the way for advancements in national defense and the future of clean power. That’s what the press release’s first sentence stressed. Note that national defense is mentioned before the future of clean power.

The fuss is all about a gain of a blip of energy barely enough to heat a kettle of water. Getting there has cost society a whopping $ 3,5 billion. That sum would buy some 2000 MW of wind power capacity that almost instantly delivers enough power to supply some 1.2 million households or a city the size of Chicago for at least 30 years. Invested in solar farms could produce even more. Or it would buy a factory to supply batteries for 1 million electric vehicles.

You may consider a 3.5 billion investment to be a minor concern, but LLNL is not a major facility. The much-criticized nuclear fusion test facility ITER in France, – still to be completed – will run way over 50 billion according to some US estimates.

Promises, promises

Nuclear fusion holds a promise of cheap, abundant, and safe energy for ages to come. That promise goes back to the 1950s and from the beginning, the time horizon for delivery was some 30 years ahead. It still is. Of course, progress has been made. But the program started in a post-war era that oozed a limitless optimism about a future in which people would live on Mars by now. In present times people are happy to be alive at all in large areas of the planet. And their outlook is grim. Promises for a faraway future have no meaning to them.

A reality check on those promises makes you see nuclear fusion from a different perspective. Apart from not being so cheap at all, its safety and cleanliness are also seriously criticized by some.

Nuclear fusion not so perfect

Daniel Jassby, a principal research physicist at the Princeton Plasma Physics Lab until 1999, worked for 25 years in plasma physics. In this article from 2017 he already performed a reality check for nuclear fusion. There he says:

“… it is time to ask: Is fusion really a “perfect” energy source? After having worked on nuclear fusion experiments for 25 years at the Princeton Plasma Physics Lab, I began to look at the fusion enterprise more dispassionately in my retirement. I concluded that a fusion reactor would be far from perfect, and in some ways close to the opposite.”

His conclusions are based on obvious facts, that rarely make it to the media. Like this one: an energy source consisting of 80 percent energetic neutron streams is not an electrical energy source. Neutron streams lead to problems with nuclear energy, as we know from nuclear fission: radiation damage to structures; radioactive waste; the need for biological shielding; and the threat of nuclear weapons proliferation.

In addition, fusion reactors share some of the other serious problems that plague fission reactors, including tritium release, coolant demands, and high operating costs. There will also be additional drawbacks that are unique to fusion devices: the use of fuel (tritium) that is not found in nature and must be replenished by the reactor itself; and unavoidable on-site power drains that drastically reduce the electric power available for sale.

Fission reactors still needed

To make up for the inevitable shortfalls in recovering unburned tritium for use as fuel in a fusion reactor, fission reactors must continue to be used to produce sufficient supplies of tritium. That leads to a perpetual dependence on fission reactors, with all their safety and nuclear proliferation problems.

Then there is the energy needed for the entire facility. That would cause about 1,000 MWe of parasitic power drain which makes it uneconomic to run a fusion power plant.

Other serious problems also afflict fission reactors, including neutron radiation damage and radioactive waste, potential tritium release, the burden on coolant resources, outsize operating costs, and increased risks of nuclear weapons proliferation.

Radiation remains a problem

To produce usable heat, the neutron streams carrying 80 percent of the energy from deuterium-tritium fusion must be decelerated and cooled by the reactor structure, its surrounding lithium-containing blanket, and the coolant. According to Jassby, the neutron radiation damage in the solid vessel wall is expected to be worse than in fission reactors because of the higher neutron energies.

The production of weapons-grade plutonium 239 is possible in a fusion reactor simply by placing natural or depleted uranium oxide at any location where neutrons of any energy are flying about.

As Jassby sums up, fusion reactors face some unique problems: a lack of a natural fuel supply (tritium), and large and irreducible electrical energy drains to offset. Because 80 percent of the energy in any reactor fueled by deuterium and tritium appears in the form of neutron streams, it is inescapable that such reactors share many of the drawbacks of fission reactors—including the production of large masses of radioactive waste and serious radiation damage to reactor components. These problems are endemic to any type of fusion reactor fueled with deuterium-tritium, so abandoning tokamaks for some other confinement concept can provide no relief.

We add the seizable investments in research and construction to that, which go at the expense of investments in clean energy and storage right now. And we can’t afford the further unproductive use of energy. Other fundamental research, like at the Large Hadron Collider, faces similar challenges and projects have been postponed already.

Fusion energy looks like one of those would-be tech solutions for the climate crisis. This one too will not work, and definitely not in time. So why waste resources on it now, when those can be used for short-term real-life solutions? It has been postponed so many times, another five to ten years delay would not hurt anyone except a few scientists, who have to find another hobby for the time being. If that can save the planet, it’s well worth it.