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By Steven B. Krivit
June 21, 2022
This article is one of three parts of a multimedia New Energy Times investigation that we are publishing today about fusion fuel claims. Here is the link to the other article, “The Missing Miracles of Fusion Fuel,” and the link to the video analysis “False Foundations for Nuclear Fusion.” We have provided the scientific and historical details in earlier New Energy Times articles.
Introduction
For at least 50 years, fusion scientists have been telling the public that the fuel for nuclear fusion is “abundant, virtually inexhaustible, and equally accessible to everyone, everywhere.” They have been saying that there is enough fuel in ocean water to provide power for humanity for billions of years.
The consensus in the fusion field is that the optimal fuel mixture for nuclear fusion is a 50/50 mixture of deuterium and tritium. These are isotopes of hydrogen. Normal hydrogen won’t suffice. Deuterium alone won’t work well enough. Neither will tritium by itself.
Fusion scientists, only occasionally, disclosed to the public that tritium did not exist in nature as a fuel source. When they did disclose it, they said that sufficient quantities of enriched lithium-6, from which tritium could be made, were available. They are not.
A Poignant Question
I received an e-mail recently from one of my readers, John Carr, a retired particle physicist living in France, who has also been critically examining nuclear fusion. Carr was reading articles in my list of scientists who have published critical concerns about fusion. A statement in Robert Louis Hirsch’s May 2021 article surprised Carr.
Fifty years ago, Hirsch was an enthusiastic champion of fusion research. In 1972, when he was 37, he was nominated to be the head of the Controlled Thermonuclear Research division of the Atomic Energy Commission. A year later, he wrote “Fusion Power: An Assessment of Ultimate Potential,” reflecting his confidence in the mainstream deuterium-tritium tokamak approach to thermonuclear fusion.
Decades later, in 2015, after reflecting on history and what he had learned, Hirsch changed his mind about the feasibility of tokamak fusion and began to express his critique publicly. In Hirsch’s recent article, “Fusion: Ten Times More Expensive Than Nuclear Power,” he wrote, “It has recently become clear that world supplies of tritium for larger fusion experiments are limited to the point that world supplies are inadequate for future fusion pilot plants, let alone commercial fusion reactors based on the deuterium-tritium fuel cycle.”
Carr asked me, “Was this truly not obvious in the 1970s when Hirsch was in charge of fusion in the U.S.?”
I began reading Hirsch’s “Ultimate Potential” paper. On Page 5, Hirsch wrote that the deuterium-tritium fuel cycle “requires tritium, which does not occur naturally and which therefore must be bred.” In half a dozen other places in his article, he identified the necessity to breed tritium from lithium.
Scientists Respond — Or Not
So, yes, Hirsch had known that world supplies of tritium were inadequate for future fusion deuterium-tritium fusion reactors in 1973. I asked Hirsch to comment on this apparent discrepancy. Here is his first response:
Tritium shortages began to be recognized in the 1990s, when the potential burden of large fusion machines was compared to plans to shut down the Canadian CANDU reactors, which have been a major source of world tritium. Mohamed Abdou was the first that I know of to recognize the tritium problem a few decades ago.
More recently, it has been recognized that the world capacity to separate Li6 from natural lithium is also limited. Li6 is needed in DT reactor blankets to breed makeup tritium after startup. The weapons program has indicated plans for new Li6 separation facilities for nuclear weapons. I’ve not seen any indication that the federal fusion program has asked for that capacity to be expanded for DT fusion reactor needs. Thus, another DT reactor fuel supply will also be limited until fusion interests finance related supply capacity.
The bottom line appears to be that both tritium and Li6 production will need to be established if DT fusion reactors are to become viable.
Hirsch seemed to be sidestepping the discrepancy. I sent him another email: “Did you recognize in 1972 that tritium for DT fusion reactors would need to come from breeding? I received a one-word answer: “Yes.”
I wrote back and said that my understanding was that the U.S. had stopped producing enriched lithium in 1963 when the Colex process was outlawed. Hirsch had written “Ultimate Potential” a decade later. I asked him why he mentioned nothing about the need to establish Li6 production for fusion energy in 1973.
He did not reply.
I sent him another question: “Were you aware in 1972 that a viable method and plant for processing enriched lithium did not exist in the U.S.?”
He did not reply.
I sent an e-mail to Abdou, the director of the Fusion Science and Technology Center at the University of California, Los Angeles, and asked him why it took so long to recognize the lithium-6 problem. Abdou did not reply.
I sent an e-mail to Ernesto Mazzucato, a retired plasma physicist from the Princeton Plasma Physics Laboratory. I had found and interviewed him in 2020. I asked him what the fusion community had been thinking about the fuel problems. He said was that the fusion community had not been thinking, period.
With none of my respondents able to explain how the multi-billion-dollar, multi-decade fusion science program had gone so far despite the lack of a viable fuel supply, I sent an e-mail to Daniel Jassby. He, too, is a retired plasma physicist from the Princeton Plasma Physics Laboratory. In recent years, he has written prolifically and boldly and has explained many of the less-favorable facts about fusion. Here’s what I asked him:
I’m guessing that, because plasma physics was focused on scientific research for so many decades, the majority of the fusion community had no reason to contemplate the matter of the Li6 supply-chain problems that would apply only to commercial fusion reactors. There had always been enough tritium for the very few experimental DT reactors. Is my understanding accurate?
His response:
Your remarks are accurate for the plasma physics research component of the fusion enterprise. However, nuclear engineering departments have been designing fusion reactors since the 1970s, and those people should have been aware of lithium-6 issues. I don’t know if they were concerned.
Infinite Optimism
If there is one person who needs to know where the enriched lithium-6 will come from, it is Tony Donné, the program manager for EUROfusion. His organization is responsible for designing the European successor to ITER, the EU DEMO reactor. It is this reactor which is intended, and in fact required, to have a full tritium breeding blanket. This reactor must breed sufficient amounts of tritium.
In January 2022, I discussed the lithium issues with Donné and asked him about his planned source for the tons of enriched lithium needed for the EU DEMO reactor. He didn’t have any. He confirmed that the enrichment technology does not exist. He hopes that a solution will appear within the next few decades.
“We have enough time until the fusion reactors are rolled out to develop the technology and set up plants to enrich the lithium,” Donné wrote.
Wishful thinking as it may be, his team does have time. But the private would-be fusion businesses that have promised commercial fusion power within a decade do not. Without several fuel miracles, these companies have no chance to provide their investors with a return on their money.
