Nuclear fusion? Not so fast
- July 1, 2023: Vol. 10, Number 7

Nuclear fusion? Not so fast

by Leigh Goehring and Adam Rozencwajg

On Dec. 13, 2022, the U.S. Department of Energy announced a nuclear fusion breakthrough. For the first time in history, scientists at the Lawrence Livermore National Laboratory achieved fusion “net energy gain,” releasing more energy than was consumed in the reaction. Immediately, journalists wrote near-utopian articles describing imminent abundant clean energy. Jennifer Granholm, U.S. energy secretary, summed up the excitement: “This milestone moves us one significant step closer to the possibility of zero carbon abundance fusion energy powering our society.”

Unfortunately, our research shows that the likelihood of nuclear fusion’s usable power remains extremely low.

There are two “nuclear” reactions: fission and fusion. During a fission reaction, the nucleus of significant, heavy elements (notably uranium) breaks apart into lighter elements. During the transformation, elemental mass converts into energy. These neutrons will lead to further fission reactions in nearby uranium atoms: a chain reaction.

Fusion, on the other hand, is a much more complicated reaction. Under the right circumstances, very light atoms (usually two specific hydrogen isotopes) fuse to create a heavier atom, releasing prodigious amounts of energy. Under normal circumstances, ions (atoms stripped of their electrons) repel each other. Extremely high temperatures and pressures (typically only found in stars) are necessary to overcome the repelling forces that prevent atoms from fusing.

As early as 1956, scientists hoped to harness nuclear fusion for helpful power production. However, while fission took six years from initial uncontrolled reaction to an early power station, controlled fusion has proved much more elusive. A critical element of a sustained reaction is the “Q” factor, which measures how much energy the fusion reaction releases compared with how much energy it consumes to create the appropriate conditions (high temperature and pressure). Until late last year, no reactor had ever had a Q-factor greater than one (i.e., more energy released than consumed). In a widely heralded event in December, Lawrence Livermore’s National Ignition Facility (NIF) announced it had finally broken the elusive barrier, achieving a Q-factor of about 1.5x.

Many journalists pointed out that even if December’s breakthrough was not yet “ready for prime time,” it proved that fusion’s widespread adoption was only a matter of time. Unfortunately, this logic is highly harmful, especially if looking for readily adaptable solutions to the CO2 production problem.

Nuclear fission is a proven technology that can be deployed at scale relatively quickly to improve energy return on investment and address carbon emissions. Gen IV nuclear fission reactors will generate as much as 180 units of energy for every unit consumed, produce little to no waste, and be “walk away” safe. Utilities could commercially deploy these technologies in at least seven years with open access to capital markets.

Instead of committing to next-generation fission reactors (small modular reactors), investors have poured about $5 billion into private nuclear fusion companies, none of which were involved in the NIF “breakthrough.”

In our view, this technology will never be viable as a source of electricity.

We commend the scientists working at NIF and elsewhere for their invaluable contributions to scientific advancement. However, the answer to our energy needs lies in a much more prosaic technology available now and operating safely for seven decades.

Vaclav Smil describes nuclear fission as the most successful failure in history. It is successful because it has achieved all of its goals; it is a failure because we inexplicably refuse to adopt it.


This story was excerpted from a report written by Leigh Goehring and Adam Rozencwajg, managing partners of Goehring & Rozencwajg. Read the full report here.

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