Nuclear Fusion Is Not Any Closer

Sensationalistic media reports are, once again, not to be trusted

Image credit: NIF

If all you know about nuclear fusion comes from the mass media, you probably think that we are just a few years away now from abundant supplies of clean energy. Unfortunately, as is so very often the case, the mass media accounts of the recent experiment at the National Ignition Facility (NIF) in the USA are amusingly sensationalistic but predictably misleading.

Before we see why this is the case, let’s first explore why nuclear fusion is so attractive as a concept.

Today, all nuclear reactors utilize nuclear fission. Fission is the name given to the process whereby the nucleus of an atom fragments, resulting in smaller nuclei and releasing quantities of radiation. Very heavy elements such as Uranium and Plutonium are quite unstable, and so they decay at a predictable rate. When atoms of Uranium decay, they emit very fast-moving neutrons. These smash into neighboring atoms, causing those nuclei to decay as well. Very quickly, a cascade develops, with ever-more atomic nuclei breaking apart and causing their neighbors to break apart also. When uncontrolled, this leads to an enormous high-energy explosion that emits huge quantities of radioactive material. Such explosions normally are reserved for nuclear weapons, but can happen accidentally as was the case with Chernobyl and Fukashima.

When carefully controlled, however, nuclear fission generates heat that can be absorbed by water or some other liquid and then the heat is used to power turbines to produce electricity. This is how all nuclear power is generated today.

Even when carefully controlled, however, fission always results in highly radioactive waste and this waste must be stored where it can do no harm, sometimes for hundreds of thousands of years. Obviously the chances of something going terribly wrong increase dramatically the longer such waste remains dangerous. This is the main problem with fission: it produces huge quantities of potentially lethal waste products.

Fusion, conversely, works in the opposite direction. Instead of beginning with large unstable atoms, it begins with very small and very stable atoms, typically hydrogen or helium. These atoms are then compressed…