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Every 1 kg of uranium contains 950 MW-days of thermal energy if fully fissioned.
Commercial reactors today produce 40-60 MW-days from their uranium fuel. This is only 60 / 950 = 6.32% of what is possible in theory.
In reality 100% fission isn’t realistic, but there still scope for huge improvements in fuel economy. This isn’t something that has happened because uranium isn’t that scarce and fuel is generally not a big fraction of the costs of a nuclear plant.
Natural raw uranium is 0.7% U235 and 99.3% U238, U235 is fissile, U238 is not.
When we enrich uranium we increase the U235 content from 0.7% to eg 4% for legacy fuel, or 19.75% for newer HALEU concepts.
20% is the NPT hard limit for civilian use, above 20% is reserved for military use and specifically the Security Council P5 (although 4 other countries have broken this).
However, the relative high availability of uranium is exactly the sort of assumption that gets you killed in industrial development competition.
If nuclear energy becomes more popular, available uranium will get much tighter. And oceanic uranium will start to become commercially viable.
However, very few reactor developers have a coherent strategy to uranium pricing and nuclear energy abundance. A coherent vision on a high adoption nuclear future puts you in a very different design space.
This is important.
The uranium cost curve is highly non-linear. There is a lot of it in stockpiles, there’s a lot of it in reprocessing, there’s a lot of it in mines. It is relatively cheap.
• USA has 700,000 tonnes of depleted Uranium stockpiles.
• There is 6 million tonnes of uranium in known uranium mines.
• There is 4.5 billion tonnes of uranium dissolved in the world’s oceans at 3 parts per billion.
• There is 40 trillion tonnes of uranium in the Earth crust, that leaches into the ocean.
If you design for stockpile economics, you must accept stockpile adoption. If you design for oceanic uranium you can assume oceanic uranium adoption. But you cannot muddle these up, that gives you an incoherent design.
Fusion is often proposed as the great solution to energy, it allows clean power with no radioactive fuel. However it is very hard for myriad reasons.
10 years ago MIT had a big magnet breakthrough and that created a lot of opportunity for new developments and funding, but the two biggest hurdles remain…
i) No working model for burning plasma.
ii) No known material (or type of matter) can survive the neutron deletions from fusion levels of neutron flux.
Nuclear fusion has 10x the neutron flux for the same thermal output as a fission reactor, plus fusion neutrons have 7x the impact energy of fission neutrons… and fission reactors operate at the limits of neutron damage.
These are not small problems. The first is a cracking SHA-256 problem (it’s why ITER is being built), and the second is an unobtanium problem. Fusion still has two Everests to summit.
Fission has several big breakthroughs that are readily available without new science, they are engineering. The solutions already exist in the world. They have already been built.
Fission and Fast Breed-Burn
The ultimate fission reactor would run on uranium 238, this is the non fissile stuff that makes up 99.3% of all natural uranium. The world has 2m tonnes of this stuff lying around, it is the tailings of uranium enrichment. It is priced at negative $50 per kg, because it is a liability to store.
We already have fuel cycles that turn fertile U-238 into fissile material. You can transmute the non-fissile uranium into fissile material. We know how to do this, many reactors in the world today are designed to do this.
This is mostly an engineering and regulatory problem. It is financable, it is insurable, it is bankable.
Further… deployment of civil nuclear energy faces major sociopolitical hurdles, these two can be solved with engineering.
There are commercial sites all over the world with 0 resident population in the zone of consequence.
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