Nuclear Loanwords

For all that a third or more of Australians will admit they just don’t know enough about nuclear technology, plenty of the associated terminology has been casually welcomed into our language.

The Bomb

The ultimate symbol for human destructiveness which needs no other descriptors, and fortunately not used as a weapon of war for 70 years. What would our parents have thought if we could go back in time and tell them there’d be no nuclear escalation of the cold war after all? Sadly, there were more Japanese casualties in the entirely conventional Tokyo firebombing than at Hiroshima and Nagasaki.

Critical mass

220px-3a_cm070922Either the required condition for a handful of specific isotopes to undergo an uncontrolled chain reaction, or a disruptive urban bike ride.


Generally used to refer to the repercussions of a pivotal event or decision. It is also often used when talking about radiological release from nuclear accidents, though more correctly it specifies only contamination from weapons detonations. 100s of these were carried out last century, and the still-measureable fallout has not had any measurable impact human health.


This is what kids do. Considering the comparative frequency and likelihood, the expensive, reactor-core destroying version could be named after the temper tantrum instead of vice versa. Three Mile Island 2 was the first major example and it proved the effectiveness of US-style Defence in Depth. If The China Syndrome comes to mind, just remember that the film was realistic enough that the reactor shut down perfectly, safely and repeatedly.


This is using a microwave to heat food, which is perfectly safe. It is also now what nuclear professionals are called in the US.


A computer game which has nothing to do with its namesake, but that’s ok. Half-life is an easy concept, but it gets counterintuitive when you consider that radioisotopes with longer half-lives generally present less hazard, not more.

Fuel rod

This only really refers to one thing, the zircalloy clad solid ceramic fuel designed for pressurised and boiling water reactors. Safe to handle when fresh, way too hot to steal or interfere with after 3 years in a reactor, and completely different to the material required for weapons in both cases, most people still vaguely know what a fuel rod is.


In 1985, time travel was nuclear-powered.

Atomic (& the atom symbol)

Perhaps a bit old-timey, “atomic” is still used by enthusiasts and professionals. While the trefoil – the symbol for radiological hazard – has been co-opted and abused by hysterical activists as a visual trigger, the atom symbol pops up widely as a more pure symbol of science and technology in general. And also where this beneficial connotation might aid marketing.



My next post will be my last for a while. With quite a bit of other work to do – and do well – in addition to a speculative science fiction novel well under way, there’s insufficient time to supply new useful analysis and commentary on this blog. My ABC Radio National article can still be accessed here, my one at The Energy Collective here, and there’s around a hundred archived posts here for interested readers. I also recommend the archived analysis at DecarboniseSA, and TCASE at Brave New Climate. I’ll be reachable on Twitter, as always.




Reykjanes Power Station

Geothermal energy is probably most often associated with Iceland, where around a quarter of electricity demand is met by using volcanic heat. This DOE video summarises the technology.

Globally, the technology is a tiny share of supply and generally sits in the “other” pie piece. As the video mentions, much work is being done to pursue the potential for geothermal as a low life cycle emissions energy source.


There has been no news on that ~500 megawatts for quite some time.

In Australia, several potential projects have been under development for some time, as described in the Australian Energy Resource Assessment 2014. The largest pilot plant in the South Australian outback supplies the community of Innamincka with 1 megawatt of power. The remoteness of this location underscores geothermal’s primary constraint. It can only realistically be considered in the immediate vicinity of appreciable underground heat resources, with transmission infrastructure necessary for delivery to load centres.

The Renewables Paradox


Looking at this image, you could be forgiven for assuming wind energy will be taking Costa Rica fossil fuel-free next decade. In reality, fully dispatchable hydro and geothermal energy, paired with subsistence-level energy use, is doing the job.

Geothermal is classified as renewable energy and is readily included as such in various regions’ energy mixes. So, in the example of Iceland, a combination of geothermal and hydroelectricity is 100% renewables. The same reasoning saw Costa Rica recently claim an impressive run of renewables-only electricity generation: about 12% from geothermal with the remainder almost all from hydro.

This seems to be in spite of the geological reality of geothermal – an average of 70% of the heat is due to subterranean radioactive decay of potassium-40, thorium-232 and both major uranium isotopes (235 and 238). 30% is left over energy from Earth’s formation.


Similarly normal radioactivity exists in the food we eat every day.

The other important detail is that enhanced geothermal systems technology involves the same method of accessing a desired volume of underground rock as hydraulic fracturing.

While the strawman argument is an undesirable rhetorical approach, it is probably very safe to say that many activists who uncritically reject the use of uranium in nuclear power plants and stand against unconventional fracked gas (regardless of what science might say) also largely support the use of renewable energy – including geothermal.


EGS is the predominant method currently being pursued.

Furthermore, many activists increasingly bolster the rejection of nuclear energy primarily on grounds of cost. But despite the most recent official Australian levelised cost estimates clearly showing that geothermal is one of the most expensive technologies, it is spared this vocal criticism and exclusion. Indeed, as recently summarised, this is a form of special pleading which has little if anything to do with their true (and even less justifiable) objections.

Just to ensure this list is exhaustive, is it not reasonable to also expect loudly-voiced concerns of groundwater contamination? And considering the many decades of protest surrounding a deep geological repository for radiological waste, activists are dramatically restrained about high pressure fluid being pumped through deep rock heated by radioactive decay.

AERA 2014 states a particularly low average thermal conversion efficiency of 12% as extracted heat is used to drive a turbogenerator. This indicates a substantial loss of thermal energy to the environment. These two considerations are often included in criticisms of conventional nuclear energy, where more like 35% of fission heat is transformed to electricity and the rest lost as steam or into an adjacent river, lake or sea. To be clear, the efficiency of steam-driven turbogenerators is the result of much incredible engineering, and heat rejected to the environment is a relatively trivial concern.

At least we’re all happy that it’s low emissions, right? Well, some motivated commentators seek to exclude nuclear energy on that basis, citing an estimate of the equivalent of no less than 60 grams of carbon dioxide per kilowatt hour generated (gCO2eq/kWh). By this reasoning, geothermal is also out when the US National Renewable Energy Labs estimates a figure of up to 80 gCO2eq/kWh.

By applying basic logic, we should be seeing organised and vocal opposition to geothermal energy. But, of course, we don’t. This isn’t even considering the indefensible perspective of advocates of a radical shift to distributed energy generation – large, distant geothermal renewable energy installations would logically have little or no place in that world.

Myself, I’m excited to see geothermal, as a dispatchable and clean form of energy, flourish and contribute, where practicable, to the challenge of displacing the dominance of coal and gas. In the long run, without misinformed, hypocritical activism ceaselessly opposing it and prohibitively burdensome regulations more than absorbing any economies of scale it can achieve, it may eventually have a good chance.