I've seen the scenario you describe as the "fission bridge to fusion" scenario, and as I understand it, a major problem is that it can't be done with existing pressurized light-water reactors. These systems just don't use Uranium very efficiently, they extract a small percentage of the energy from the fuel, and then need to be refueled.
This doesn't mean the "fission bridge to fusion" is impossible by any means, but it does mean that significant work needs to be done in developing and commercializing next-generation fission reactors, including breeder reactors, which use much more of the available energy from fuel, and possibly novel reactor designs that can run on reprocessed fuel from LWRs.
A political complication is that large-scale commercial nuclear fuel reprocessing represents a nuclear-weapons proliferation risk, and so might imply regulatory burdens, or require international agreements on use and control before it can go forward.
Peak uranium isn’t a thing even using today’s inefficient reactors.
The key insight is that if you’re using fission to power DAC, then you don’t even need to worry about proliferation. Countries can continue to use coal and oil while nuclear fission is used for DAC. An international agreement that they pay a tax to the countries that do have the capability to do DAC powered by fission. China and USA make up the vast majority of emissions, make up a good chunk of global GDP and both have nuclear power plant capabilities & they're not the only two countries who have that. Yes, there’s an imbalance there to think through but it can be remediated a bit (and mostly it’ll be Brazil and India that we would need to worry about assuming we can get China on board). Certainly better than doing nothing for decades or even a century.
'A resource is that amount of a geologic commodity that exists in both discovered and undiscovered deposits—by definition, then, a “best guess.” Reserves are that subgroup of a resource that have been discovered, have a known size, and can be extracted at a profit'
I'm asking because I'm definitely not an expert on this, but if we can't use uranium efficiently, wouldn't that mean the plants would be creating lots of waste they wouldn't if they were more efficient? Would plants that would already be built be upgradable in the case more efficient methods of using uranium come online?
Once the uranium cartridge is depleted after several years, that becomes waste. There are mostly 2 ways to deals with it:
1. Like US or Sweden, you take it as-is and bury it.
2. Like France and Japan, you recycle it to make more cartridges. France has a dedicated facility for it, Japan used to send its waste to France for recycling.
You can reprocess “waste” in a breeder reactor. Not sure if plants can be retrofitted with a new generation of reactor, but even if you need a new plant that’s not that big a deal because the waste is still usable fuel (it’s not a use once thing)
Because all the cost must be paid upfront, and takes 10+ years before the first GWh gets out. So, it does not fit well with private investors.
The cost of the electricity exiting a nuclear reactor is directly related to the cost of money (interest) to build the reactor. The reason is because it is cheap to run the reactor once built.
So, the cheaper the money is the cheaper the electricity is.
That is why it is not interesting for private investors.
It has to be financed by state to minimize the final cost if electricity at the end.
> The reason is because it is cheap to run the reactor once built.
Though nuclear plant operating costs have come down considerably since peak in 2012, the same is true of wind and especially for solar, still leaving nuclear power's operating cost per megawatt-hour above that of wind and solar. Though nuclear has the advantage of consistent power gen regardless of weather or time of day, it also requires $9B (far lower today) in construction costs and at least 5 years to get running, assuming no delays, while materials and installation of solar or wind is a fraction of that cost, and can be producing power in 6 months to a year. Nuclear energy not only requires engineers from a shrinking field, but heavy security, which will prevent operating costs from dropping much lower even if Uranium suddenly becomes cheap, which can't happen. A nuclear plant will require about 27 tonnes of Uranium at an average cost of about $47/lb., about $2.7B in Uranium alone.
There must be a way to make nuclear power plants cheaper without sacrificing safety.
Despite the large upfront cost, nuclear still provides cheap electricity. Currently, the price of the electricity generated by nuclear is more impacted by the way the upfront cost was financed than by the price of the combustible (uranium). You can see the difference between the electricity price for a UK nuclear power plant (private investors), vs. a French power plant (state investor). The private investors request 10% interest. The state investor request few percents. On a ~$10B tab it makes a difference and for a long time.
If we get serious about nuclear, we could find a way to build it a bit cheaper, and even faster (and with interests that would make it cheaper).
There might be also an argument to make, that nuclear might be too safe for its own good, and we could relax the safety measure. Not trolling here. Given the number of death due to nuclear power plants (near zero) are we too cautious at the expense of its deployment. I suspect that relaxing the safety rules is what some governments might have to decide if the fossil energy becomes just too expensive, they could stretch and extend the life span of the reactors beyond what was previously deemed safe.
And the population should be informed about the real risk of nuclear...
Nuclear has an underserved extremely bad reputation (maybe due to the bomb A/H, or how media reported on Tchernobyl/Fukushima ?). Earth had natural nuclear reactor that have been running for thousands of years (https://en.wikipedia.org/wiki/Oklo_Mine), and nature littered the waste everywhere. On the other hand, we carefully confined our nuclear reactions, and store properly waste (in most countries everything exiting a nuclear facility is considered nuclear waste, even though there is no trace of radioactivity whatsoever).
We probably poison general population way more with chemicals and yet the general population does not seem too worry to have chemical factories all around. Silicon Valley dear Palo Alto is a superfund (https://cumulis.epa.gov/supercpad/SiteProfiles/index.cfm?fus...). Did we abandon the site ? No, we excavated and off-site disposed of approximately 10,700 cubic yards of soil, ventilated all the buildings so you do not smell the Palo Alto cookie dough (http://www.aarongreenspan.com/writing/20130404/in-search-of-...). And no one is batting an eye. The groundwater is contaminated and yet the real estate is a premium to raise a family.
We have 12,000 people dying in stairs every year in the world (https://www.medlegal360.com/fall-down-the-stairs/), and yet we have nowhere near the same safety measures for those evil stairs that keep killing every year. Is it due to the powerful lobby of the carpenter's guilds? No, we are just careful when going down the stairs.
We have very different risk tolerance with radioactivity. Probably because we cannot "see" it with our senses. We are wired to fear what we can grasp with our senses. I will still go down the stairs recklessly, unless maybe I actually witnessed someone die in a stair. Yet there are radiations everywhere, some of us are more exposed than other. And our body is engineered to deal with it, to a certain degree. For instance, according to IAEA:
"The individual dose limit for radiation workers averaged over 5 years is 100 mSv, and for members of the general public, is 1 mSv per year." (https://www.iaea.org/Publications/Factsheets/English/radlife). Yet we let flight attendants flying without any radiation monitoring, even though they are technically "radiation workers" with some even likely passing the recommended 20 mSv/yr limit.
Getting radiation and breaking our DNA is part of life. Life on earth from the beginning had to put in the specs a way to repair, as we have been and still are attacked by radiation and oxidation all the time. Our body due to oxidation alone breaks hundred of thousands of cells every day. A major part of our DNA is solely responsible to repair it. And yes, sometimes it fails (cancer). But getting radiation (dentist, flights, etc.) are considered fine, as long as you do not do it too often.
A well run nuclear reactor should not be more worrisome than a well run chemical plant.
Let's build some good (breeder) nuclear reactors !
Reprocessing increases net efficiency considerably [1]. Few people do it since uranium is very cheap relative to the amount of energy extracted from it, even without reprocessing. But if fuel ever becomes constrained, reprocessing would become competitive.
Nuclear weapons proliferation isn't a risk among most countries that have nuclear generation programs. Heck, most of them already have nuclear weapons. The rest can contract out reprocessing to nuclear-armed countries.
Also there are "near-breeder" CANDU heavy water moderated reactors: they are a proven technology that exists today and can use non-enriched uranium. They also in theory can use a plutonium/thorium mixture, so can burn thorium.
They are cheaper as far as fuel, but it turns out that fuel didn't become as expensive as anticipated in the 1970s (when it was thought that there would be 1000s of reactors). They are physically larger, so have a higher construction cost that put them at a disadvantage compared to conventional LWRs.
The tritium needed for fusion reactors comes from these CANDU reactors (some of the deuterium from the heavy water is converted to tritium, it is collected).
This doesn't mean the "fission bridge to fusion" is impossible by any means, but it does mean that significant work needs to be done in developing and commercializing next-generation fission reactors, including breeder reactors, which use much more of the available energy from fuel, and possibly novel reactor designs that can run on reprocessed fuel from LWRs.
A political complication is that large-scale commercial nuclear fuel reprocessing represents a nuclear-weapons proliferation risk, and so might imply regulatory burdens, or require international agreements on use and control before it can go forward.
Refs: Dim recollection from reading Walter C. Patterson's "Nuclear Power", and some discussion about peak Uranium (https://en.wikipedia.org/wiki/Peak_uranium).