At 1:00 a.m. Pacific Time on Dec. 5, 2022, the National Ignition Facility at Lawrence Livermore National Laboratory in California created nuclear fusion without thermonuclear detonation. The experiment, heralded in the Department of Energy’s own release as history-making and announced Tuesday by Secretary of Energy Jennifer Granholm, converted 2.05 megajoules of laser energy into 3.15 megajoules of energy from fusion, all produced and recorded and spent in less than a blink of an eye. It is, at once, a meaningful scientific achievement, and one whose entire reason for being rests inside the long-term work of sustaining an arsenal of oblivion.
“Our thermonuclear weapons have fusion ignition that takes place in our weapons, so studying fusion ignition is something we do to support the stockpile stewardship program,” Mark Herrmann, Lawrence Livermore’s program director for weapon physics and design, said during a technical panel on Dec. 13. “In addition, fusion ignition creates these very extreme environments that we have no other way to access on Earth. In this experiment, for the first time ever, we were able to put some samples of materials that are important for future stockpile modernization efforts that are going on at Lawrence Livermore today in very close to this intense neutron burst and then see how did they respond to that intense neutron burst.”
The stockpile stewardship in question refers to the continued existence of the U.S. nuclear arsenal, the second-largest in the world. Nuclear weapons, though bound to their origin in World War II and development throughout the Cold War, are an ever-present fact of modern geopolitics. They are an enduring threat, and to a large degree the work of stockpile stewardship is about making sure the weapons the U.S. already has will work, if a president gives the order to launch.
“We’re using the output from these really cool science experiments to actually test materials for stewardship applications,” said Herrmann, in a phrase that seemed exactly backwards. The great discovery of the day was scientific, but the facility exists for weapons science first, civil energy second at best.
Ground broke for the National Ignition Facility on May 29, 1997, with construction continuing into 2009. The initial impetus for the facility dates back earlier, with its concept first theorized in 1959-1960—less than a decade after the first hydrogen bomb test. Hydrogen bombs are two stage, using an atomic fission reaction to trigger a fusion reaction in a second nuclear core in the same warhead. In warhead design, the focus is on intense power, creating the most destructive force from the fewest needed inputs.
Fusion as energy, instead, promises to be self-sustaining after it’s initiated, which means the input energy need not be the kilotons of atomic detonation. A 1 megajoule lasers, first demonstrated in 1960, could provide one avenue for energy production.
In the Dec. 5 test, the 192-laser array of the National Ignition Facility directed 2.05 megajoules into the target, which briefly produced 1.5 times the energy pumped into it. That’s a gain of energy within the reaction, but not in overall terms. Kim Budil, director of Lawrence Livermore National Laboratory, noted that the test took “300 megajoules from the wall for 2 megajoules of laser.”
During the Cold War, the U.S. continued to develop and refine nuclear warheads through live testing. After the Partial Test Ban Treaty of 1963, the country continued nuclear tests underground (literally, not figuratively), up until Sept. 23, 1992. On that day, “Divider,” an otherwise routine test to ensure warhead reliability, became the last live nuclear detonation by the United States.
A moratorium on live testing and the dissolution of the USSR in 1991 meant the immediate risk nuclear peril had diminished, though was hardly absent. While the U.S. and Russia (which inherited the USSR’s warheads and weapons) decreased their overall stockpile size down to under 6,000 warheads apiece, the logic of nuclear weapons meant that the U.S. wanted to ensure its warhead still worked.
Now, though, the U.S. needed a way to do this without live nuclear tests.
“Earlier this year I had the opportunity to remember the 30th anniversary of Divider, the last explosive nuclear weapons test conducted by the United States,” Jill Hruby, undersecretary for nuclear security and administrator for the National Nuclear Security Administration, said at the DOE’s Dec. 13 press conference. “In reflecting on Divider, I spoke on how far our stockpile stewardship program has come, and in how many ways we now understand our nuclear weapons better than we did when we were testing.”
Among the ways the National Nuclear Security Administration maintains America’s existing stockpile are materials tests and computer simulations. Using data gleaned from the 1054 live nuclear tests, as well as now decades of computer models, nuclear researchers at labs like Los Alamos and Lawrence Livermore have continued to design and refine how these weapons work.
“Fusion is an essential process in modern nuclear weapons, and fusion also has the potential for abundant clean energy,” Marvin Adams, NNSA deputy administrator for defense programs, said during the Dec. 13 presser. “As you have heard, the breakthrough at NIF has ramifications for clean energy. More immediately, this achievement will advance our national security in at least three ways.”
Those three ways all emphasized the importance of nuclear science for maintaining and sustaining a nuclear deterrent, without conducting live explosive nuclear tests. Having the scientific expertise and skill to evaluate nukes without detonations lets the U.S. show the world it knows what it’s doing when it comes to nuclear weapons, said Adam. It also lets the U.S. prove to allies that, because the American nuclear arsenal is well and competently maintained, there’s no need for these countries to develop their own nuclear programs.
As a way of strategic thinking, a nuclear arsenal is a tool that deters and constrains the actions of other nations, especially other nuclear-armed nations, because the threat of retaliation is far greater than any gain from initiated war. Deterrence is a theory with limitations; nuclear-armed Pakistan and India have fought multiple wars, though the wars fought have been on a small scale. Similarly, soldiers from nuclear armed India and China regularly engage in melee skirmishes along disputed sections of their border. These skirmishes are fought with sticks and stones in the shadow of nuclear oblivion, with guns set aside so as to not escalate the violence.
Deterrence theory also shapes the kinds and types of military aid the United States provides to Ukraine as it fights against Russian invasion. Weapons with more immediate battlefield utility have been prioritized over long-range missiles, which could be seen as a threat not just to Russian soldiers but to Putin himself.
While Russia’s nuclear arsenal has long been at the foreground of U.S. strategic thinking, China’s growing nuclear stockpile and expanding array of missiles and launch sites, are an increasing part of the Pentagon’s calculus. Deterrence holds fear of oblivion alongside fear of obsolescence. Fear that warheads may not detonate properly on arrival is one of the factors driving a restart of plutonium pit production at Los Alamos, as the lab tries to refurbish old warheads out of a concern that essential bomb components may have decayed in the decades since they were assembled.
“Unlocking ignition at NIF will allow us to probe the extreme conditions found at the center of nuclear explosions, and address significant long-standing stewardship questions,” said Hruby.
The clean energy promise of fusion is one step closer after the Dec. 5 test, even at the small scale of energy gained. The work of turning that success into a sustainable basis for fusion power plants is still likely decades away, even if the timeline might be shorter than the often-quipped 50 years away.
In the meantime, the nuclear labs at NIF will continue to better study and understand the materials and science of nuclear warheads and explosions. There’s always room on the budget for the science of energy (destructive), even and especially as it incidentally leads to breakthroughs in the science of energy (productive). Just don’t expect the weapons research to get the same high-profile publicity from the DOE or Secretary Granholm.