I have talked before about using isotope heat in various practical applications, including freeze protection in northern Canadian communities. In a CBC radio interview on this, I mentioned to the interviewer that there is nothing unnatural about this: hot springs, such as those found in Radium, British Columbia and Ems, Germany (the famous spa resort town from which the infamous 1870 telegram was sent) get much of their heat from decaying uranium, thorium, and potassium radioisotopes. In fact, these natural radioisotopes constitute much of our planet’s internal heat source. Dougal Jerram, an earth scientist, in his book Introducing volcanology : a guide to hot rocks, gives radioisotopes a prominent role in his explanation of the awesome processes that melt hard rocks into liquid.
Of all these processes, none are as awesome as those involving the strong and weak nuclear forces. Most of the decays in the natural uranium series involve alpha particle emission, which is a manifestation of the strong force; those involving beta particle emission involve the weak force. The weak force’s most famous manifestation is the Higgs Particle.
My point in the CBC interview was, there is absolutely nothing unnatural or new about nuclear radiation. Though is was not until 1895 that Henri Becquerel identified nuclear radiation as a phenomenon in its own right, isotopes of uranium, thorium, and potassium in terrestrial rocks have been decaying literally since before the earth began. They were decaying many centuries before Caesar conquered Gaul, they were decaying when the Prussian emperor sent the fateful telegram from Ems in 1870, they were decaying when the German government adopted the nuclear phaseout in the late 1990s, and they will be decaying for many billions of years after we’re all gone. They are one of the truly physical constants through the rise and fall of every single human civilization that has ever existed or ever will exist.
Radioisotopes are what is providing the heat that drives Iceland’s famous geothermal generators, which the government says provide a quarter of the country’s electricity. In light of this, does geothermal power qualify as renewable? Given that the half life of uranium-238, the most prevalent uranium isotope, is 4.5 billion years, it is safe to say yes.
My recommendations for the use of radioisotope heat for freeze protection in northern Canadian communities involve an isotope with a far shorter half-life. Strontium-90, a beta-emitter with a half-life of only 29 years, is often produced when a uranium-235 atom splits, or fissions, into two lighter fragments. Fission also releases enormous amounts of heat—the whole purpose of nuclear power reactors, which use that heat to turn electricity generating turbines. The strontium-90, along with the radioactive isotopes of other elements, is just a byproduct of fission.
But Sr-90 also decays with great vigour: when it decays to Yttrium-90—and when Yt-90 decays to Zirconium-90—it ejects a high energy negatron (a subnuclear particle that along with an antineutrino is part of a strontium-90 neutron’s spontaneous transformation into a proton). When this negatron, which is essentially an electron, slams into the first material it encounters, it generates a relatively large amount of heat.
I did not just dream this up: Sr-90 has powered electronic devices since the late 1950s. However, because of fears of radioactivity, its use has been mostly discontinued. In one case, Sr-90 provided the power source for a nuclear test-ban treaty monitoring and verification site in Alaska. A nearby tundra fire made local Aboriginal tribes aware of the fact that the site was essentially nuclear powered. They objected to this, on the grounds that this is their ancestral land and artificial isotopes sully it.
Well, a few hundred meters down from the tundra, towards the core of the planet, other isotopes are generating enormous amounts of heat. They have been doing so for billions of years, and will continue to do so for many billions of years after all Sr-90 has turned into zirconium.
And the discontinuation of Sr-90 at the Alaska site has just led to its replacement with propane, a far less efficient and more dirty energy source.
There is nothing unnatural about radioactivity. We should use it.
Note: Ems is just over 100 kilometers from Bonn, the scene of the most recent climate change non-event. Those who wonder why climate talks so consistently fail might ask why Germany is so anti-nuclear—given that the famous Ems hot springs are themselves nuclear powered and in fact are a destination for people who want to get healthy.