Recent headlines about a ‘major breakthrough’ in nuclear fusion also hit the headlines in December. Many reports misleadingly suggested that a future of abundant clean energy produced by fusion nuclear power is just around the corner. Some (such as the Guardian) did note that “major hurdles” remain, and they certainly do as a power station would need to generate significant electrical power for much longer than a few seconds. So far the facility can carry out one shot a day rather than the 10 times a second needed for energy production. And the fuel pellets costs $100,000 to make. But there is another angle, as an interview with Bob Rosner, a physicist at the University of Chicago, appearing in the Bulletin of the Atomic Scientists revealed. The experiment was not for electricity generation but for the maintenance of nuclear weapons.
Nuclear fusion involves heating atoms and forcing them together to fuse into a heavier atom and emitting a small amount of energy. It is the process which gives the Sun its energy and was used in the first thermonuclear explosion in 1952. But it has never been achieved before under controlled conditions in a laboratory. Researchers at the US Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) focused 192 powerful lasers on a target of deuterium–tritium fuel, compressing it to a point where the atoms combined to form helium plus energy. On this occasion more energy was produced than was used by the lasers. However, the whole process was undertaken in order to support the Stockpile Stewardship Program which monitors the US nuclear weapons stockpile and has only a distant connection to power production. Stockpile stewardship is about trying to ensure that aging nuclear weapons will still work without the need for nuclear tests, which means developing accurate computer simulations and laboratory tests.
Basically, this success will send a signal to adversaries that the US is able to do what they say they can do. For them, that’s a big deal.