Ashes to ashes: the easily traceable dust of Ontario nuclear energy

“Why, may not imagination trace the noble dust of Alexander till a find it stopping a bung-hole?” So wonders Hamlet (Act V sc. I) after examining Yorick’s skull. And while it might be a tad morbid, and certainly would mortify Alexander’s admirers, Hamlet’s question is perfectly reasonable. We are all made of dust, so why is it not conceivable that the physical remnants of even Alexander the Great or Caesar himself could not wind up serving such a base use? Especially when you consider the sheer volume of material into which those remnants could fold, and the innumerable routes, pathways, and currents along which they could naturally migrate in that volume through the ages.

Hamlet ponders fluid dynamics. If he were holding a nuclear fuel bundle instead of Yorick’s skull, Hamlet’s imagination would have no trouble tracing the bundle’s passage through the cycle of inception to interment and beyond. That is because the bundle is more scrupulously managed, documented, and accounted for than Yorick’s skull was. This management, documentation, and accounting has already been paid for, through the (low) rate charged for nuclear electricity. We could not say the same about the waste from gas-fired power generation. That waste is simply dumped, by the kiloton, for free, into our planet’s atmosphere.

But I know of at least one volume of material we could safely rule out—the country rock of the Canadian Shield. The country rock of the Grenville Province of the Shield, for example, has been identified as being generally about 900 million years old. This is heavily metamorphosed material, and if you have ever seen Shield gneiss and pondered its crazy twists and turns it’s hard not to shudder when you think of the immense heat and pressure that formed it. We know where this stuff ended up, and roughly when it was formed. We have a less-than-clear idea of where on earth it came from. Of course it is highly unlikely to contain in its crystalline structures even small bits of Alexander or Caesar—its creation predates them and all other humans by hundreds of millions of years.

As difficult as it is to trace the migration of the dust of Alexander or Caesar through even the earth’s biosphere or hydrosphere (forgetting about the lithosphere), it would be far more difficult to trace those parts of either of them that turned into gas instead of a fine-grained solid. Though the earth’s atmosphere is minuscule in mass compared with the lithosphere—it accounts for only 0.07 percent of the earth’s mass—it is still 96 kilometers thick. For us surface-dwelling humans, those 96 kilometers are a pretty decent layer of protection from all sorts of dangerous stuff incoming from outer space.

These 96 kilometers also indicate the size of the volume that accommodates the roughly 5 quadrillion metric tons of gas that comprise the atmosphere. Like solids, gas molecules are never at rest. But they move far, far more quickly than solid molecules. Their range within the vast volume they occupy is virtually limitless. And their path is random: though atmospheric air currents follow a pattern, these are macro-scale phenomena. The branch of physics called statistical mechanics was invented because it is simply impossible to know the behaviour of molecules at their individual scale. A 44-gram parcel of carbon dioxide for example contains over sixty thousand billion trillion molecules, which at one atmosphere pressure and 0° C would fit into a container just slightly larger than a 20-litre water jug. With such a gigantic number of individual particles, all you can do is guess, using statistics and quantum mechanics, at the probabilities that certain portions of them will behave this way or that. Release 44 grams of CO₂ gas into the atmosphere, then try to track each molecule through a volume 96 km thick which envelopes the entire globe. And good luck.

This 20-litre container could not hold a mole of CO₂ at standard temperature and pressure. To fit a mole (44 grams, comprising 6.022 x 10²³ individual molecules) of CO₂ into this jug, you would have to cool the jug’s internal temperature to -29° C while maintaining pressure at one atmosphere.

We do know the origins of some of the gas molecules in our atmosphere, of course. But we know them on the collective, bulk scale. Through our knowledge of the abundance of naturally occurring isotopes of carbon, and the preference on the part of green plants for the lighter carbon-12 isotope over carbon-13, we have a good idea of the amount, in billions of metric tons, of CO₂ that we humans have dumped into the atmosphere since the Industrial Revolution. (That amount is in the order of half a trillion metric tons; see article).

But can we tell, for example, which CO₂ molecule was produced in which coal-, oil, or gas-fired engine? Look up to the left, in Table A2; it shows most of the large-scale electric power generation so far today in Ontario. In the Gas category, you’ll see that the fleet of gas-fired units (there are 43 of them) produced hundreds or thousands of tons of CO₂ (it depends on the time of day you view the table). Can we identify, from an analysis of the CO₂ that is currently swirling around in the planet’s atmosphere, the CO₂ that came out of an Ontario gas plant today?

Unless we could radiolabel some of the methane in the gas prior to combustion, no, we couldn’t.

All we can say is that the provincial gas plants added 6,850 metric tons of CO₂ to the planet’s atmosphere between midnight and 11:00 a.m. on December 16 2014. That is enough CO₂ to fill Rogers Centre, home of the Toronto Blue Jays, more than twice (see article).

Now, have a look at Item A1 in the upper right: it is the latest measurement of the atmospheric concentration of CO₂ taken at the Keeling Observatory in Hawaii. At the time of writing (December 16 2014) it was 399.35 parts per million. One part per million of a mole of air is 6.022 x 10¹⁷ particles, give or take a few hundred million. So a mole of air in Hawaii with a 399.35 ppm concentration of CO₂ would contain roughly 2.4 x 10²⁰—in everyday parlance, 240 thousand quadrillion—CO₂ molecules. Sift out those whose carbon component is the carbon-12 isotope—which makes it more likely that that molecule is the product of human combustion of a fossil fuel, possibly methane (“natural gas” is the trade name for methane)—and you still have a mind-bogglingly huge number of CO₂ molecules. Is it possible that any of them could be from an Ontario gas plant? Hamlet would surely agree that it is possible.

More important, even if we could trace each molecule of Ontario gas plant CO₂ in its journey through earth’s mighty and turbulent atmosphere, we surely could not recover it and return it to the company that owns the power plant that made it, so that that company could properly store it sequestered from the atmosphere.

And even if we could do that, even if we could recover the 6,850 metric tons of CO₂ that Ontario gas-fired plants have dumped into the planet’s atmosphere from midnight to 11:00 a.m. today, what on earth could the owners of the plants that made it do with it? Remember, that amount of CO₂ would fill two Rogers Centres. But the plant owners could not possibly afford to build two Rogers Centre-size repositories to hold their waste CO₂ every time they make 6,850 tons of it. They make on average enough CO₂ to fill eight Rogers Centres per day.

That’s 2,920 Rogers Centre-size repositories per year.

If the owners of gas plants were required, like the owners of nuclear plants are, to recover and store and account for every particle of waste they produce in the course of generating electricity, the cost of gas-fired power would be so impossibly high that they would have to get out of the business. In fact, the gas-fired power business would simply stop being even remotely viable. It would cease to exist.

This is a bit sobering to realize, especially when you consider that the gas-fired power plants that made the 6,850 tons of CO₂ from midnight to 11:00 a.m. made less than seven percent of Ontario’s electricity during that period. And that that seven percent contribution would entail the production of enough CO₂ to fill Rogers Centre 2,920 times in a single year.

What made the other 93 percent? Mostly nuclear (64.3 percent) and hydro (23.8 percent).

Now, with nuclear energy, we can trace each gram of material, from the moment it is dug out of the ground to when it is placed in a half-meter-thick concrete and steel container at the generating plant that used it to make electricity.

Moreover, we—or at least those of us who live in Ontario and pay an Ontario electricity bill—have already paid for the management and storage of each and every gram of used nuclear fuel that has been produced over the course of Ontario’s fifty-year nuclear history.

It doesn’t take someone with Hamlet’s prodigious imagination to trace this dust from cradle to grave, nor to trace the money flows into and out of it. It is pretty straightforward.

In the end, Ontario used nuclear fuel, reused and recycled or not, will return to the earth. It might go into a billion-year-old stable formation in the Canadian Shield, though likely not in Grenville Province. Regardless: its final resting place has already been paid for. Some lucky community, possibly in the northern part of Ontario, will host this resting place. Aside from a smallish, extremely highly engineered underground repository, that community will be physically unaltered. But economically it will see unprecedented prosperity: stable long-term well-paid employment, and all the happy spinoffs.