Ever since the first commercial reactors have started to produce electricity for the grid in the 1950’s (um, about 70 years ago now…) we keep hearing how nuclear is the clean, green power of the future. No emissions, no limits, just the infinite power of the atom. Even M. King Hubbert, the renowned petroleum geologist who pointed out the reality of peak oil production, has seen it as an infinite and stable energy source. (Don’t ask me how he could hold these two contradictory thoughts in his head at the same time.)
Today we know — although many still try to deny — that he was spot on with his first observation. Oil is a finite resource and it’s extraction follows a rise, peak, plateau and fall curve. Conventional oil (the scope of Hubbert’s studies) has peaked around 2005, and is on a bumpy plateau ever since, with growth only provided by unconventional and increasingly difficult and energy expensive to get resources. I wrote many articles on the not so fantastic prospects this has in store for us, so now let’s examine the proposed alternative to fossil fuels: nuclear energy.
I’ve mentioned in the introduction to this article how Hubbert has presented a glaring contradiction between the reality of peak oil and his expectations towards nuclear power supposedly providing us all the energy we need for countless millennia to come. I say glaring, because as a geologist it should have been obvious to him that nuclear power is coming from Uranium, a mineral found in finite quantities, in finite reserves on this finite planet. In other words: the same rise and fall in its extraction is all but guaranteed.
Production starts at the best locations, where the most dense and easy to get forms of Uranium ore can be found. Like the ones in Canada, with 20% U content (a fantastically high concentration for any metal by the way). The issue is: such high grade ores are rare. They are like the golden tip of Khafre’s pyramid. Shiny, easy to work with, but not too much compared to the rest of the reserves.
Imagine that all the Uranium ores ever mined (and yet to be mined) were brought into one location by the Gods. There they would pile it up into a shape of a gigantic pyramid, putting the highest quality ores from Canada, like a cherry, on the top. The next, more voluminous layer in this imaginary pyramid of Uranium resources then would consist of ores with 2% Uranium content (where the rest is mining waste containing less valuable metals in various quantities). As you can see we have much more of these, but still not enough to power the entire planet with. Moving down another layer we would find much much more Uranium albeit locked up in ever lower grade ores containing a mere kilogram of pure Uranium in every ton hauled to the surface (or 0.1%).
Notice how we jump orders of magnitude in density as we move up and down this pyramid: 20% on the top is ten times as dense as a 2% ore, which is twenty times as dense as a 0.1% ore in a row below. At the bottom layers we would find common granite and sedimentary rock containing mere grams of Uranium per ton of ore mined: 3–5 ppm that is (or 0.0003%). Good luck mining, hauling then crashing tons of the hardest of rocks this planet has to offer, only to try and extract a few grams of Uranium out of it.
Long story short: we have only a very little amount of high grade, easy to mine Uranium and billions of tons of low grade, hard to find, hard to extract metal dispersed around the surface of the planet. Just like with every single other material we’ve ever mined.
Now, armed with this knowledge, look at the chart below.
Preposterous as it may sound, our Uranium resources refuse to grow in line with the money we pour on exploration. We are simply unable to grow our good old high quality low cost reserves. What we have found instead is of an ever lower quality type, containing less and less U per ton and costing more and more to extract. Despite a virtual explosion in exploration expenditure (doubling the total amount spent in 12 years between 2005 and 2017) our reserves grew by 60% only — then flat-lined — indicating a peak in exploration.
Let’s face it: Uranium exploration has hit diminishing returns with current reserves are now estimated to be enough for 90 years — not 5000 as suggested by Hubbert. Spending more on exploration will not give us large quantities of high grade resources in return. What we are left with is of ever lower quality and costlier to get ores. It doesn’t matter if the oceans or Earth’s crust contains millions of tons of Uranium in theory. In practice it’s in such a diluted form that it would take more energy to scrub and collect the radioactive metal than the energy we could get out of reactors in the end.
What matters is net energy: if there is nothing to gain, then why do it…?
This is how, Dear Reader, a natural limit to growth look like. (Not unlike the situation we experience with oil.) Perpetuating the myth of “high prices bring about more supply” will not help here. Expecting that higher prices will make the extraction of low grade reserves economic (basically all the new discoveries) in an energy constrained world, is nothing but magical thinking.
Uranium is mined (still to this day) by using diesel machinery and ever more costlier electricity. Mining lower grades would mean even higher energy consumption as more rocks per unit of Uranium would need to be shoveled and hauled to the surface. While for example a numerical difference between a 1% grade and 0.1% grade is just 0.9% point, it actually requires 10 times the effort (diesel and related machinery) to bring up the ore from the mining pit, then an additional 10–100 times increase in the energy use of the grinding and leaching process. There is nothing to invent here: the work has to be performed and it has a certain energy need dictated by physics and geology.
Now let’s take a look at actual Uranium production. At the end of the first Cold War extraction fell due to political reasons: the arms race ceased for a while and many nuclear weapons were dismantled and used as reactor fuel. There was a supply glut. Even though demand was on the rise, production levels seen in the cold war era was no longer required. At least not until the early 2000’s.
As stockpiles started to dwindle there was a renewed interest in mining. This time though high grade reserves were already mined, and only lower and lower grades could be brought into production. As it can be expected in such a case, producers have started to hit all sorts of problems as a result.
Even Kazakhstan, the world’s largest producer has hit limits to growth and falling profitability. The global energy crisis (both on Natural Gas and on the Diesel front) has just made their position even weaker and more exposed to protests from workers who wanted to have a compensation to rising living costs (and rightly so). This is the curse of resources: as they deplete their extraction gets costlier and costlier while their price is unable to follow this trend.
We already face a supply gap, which will only keep growing as cheap resources keep depleting. Expanding the fleet of reactors will further increase this gap, weighing even more on an already stretched supply and national stockpiles.
Needless to say, this is unsustainable. If Uranium prices don’t rise significantly then suppliers will have to stop mining. We are at around 110 USD/kg and most reserves need 130 USD/kg to become economic — not to mention newer reserves needing 260 USD/kg to be tapped. If prices do rise to this level then this would force poorer nations to retire their fleets and cancel projects in droves, causing prices to fall again. Needless to say, this zig-zagging of prices would make any incentive for discovery and ideas of utilizing lower grades vanish. (Just like with oil).
If you have pinned your hopes on nuclear, I have very bad news to serve: Uranium production will peak (if it hasn’t already). Since exploration has already hit diminishing returns in 2011 this was only a question of when, not if. No wonder: we live on a planet constrained by geology and physics, not money.
Then new reactor designs will surely save us! Well, breeding and 4th generation reactors are still in development phase and nowhere near commercialization. It will take decades to have them approved and to sort out all kinds of technical and safety issues. Even the Chinese, who are the forerunners of this technology, do not plan to build their first experimental reactors till the 2030's… We don’t have that much time left. Oil is about to start its long decline this decade — first slowly and tentatively, then ever faster — causing all sorts of problems preventing us from investing in these untested technologies. Besides, all these new reactors would use is a finite fuel source still (U-235), already peaking then declining.
As diesel gets ever scarcer and harder to get by, servicing older reactors will become ever more problematic. We need long term thinking here: reactors will still need active care and cooling decades after their decommissioning, and if we lose grid stability (which is very much a near term concern), then a longer blackout could cause unwanted problems (again, we will not be able to rely on diesel generators helping us out for long either).
Based on the above, it is neither sustainable, nor safe to expand nuclear reactor fleets. We would immediately need to start digging long term storage locations not too far away from existing reactors while we still have the resources and fossil energy to do so, and plan nuclear power’s safe retirement once all the available fuel has been used up. Peak oil is not the apocalypse but a long emergency. We need to act accordingly and use nuclear energy as a short to mid term ‘solution’ only, before unsolved problems simply overwhelm us.
Until next time,
B
