I'm generally in favor of Nuclear, but they need to complete their whole-life planning before opening new plants. Presently, the status quo plan is to store nuclear waste at or near where it is generated in perpetuity. That's a pretty big unfunded liability in terms of risk management, security and maintenance. What is the future present value of managing a nuclear waste site for several hundred thousand years across risks we can't even imagine? That's a pretty big known unknown.
That's the status quo only because the government shut down its long-term storage facility, for which nuclear companies have already provided $46 billion.
However, for the fast neutron reactors supported by this new law, long-term waste storage is less of a problem. 99% of our nuclear waste is U238 and transuranics, all of which are fissioned in fast reactors. The remaining 1% is fission products, which have much shorter half-lives. For those, the general idea is to encase them in glass blocks and bury them; they'll be back to the radioactivity of the original ore in 300 years.
Are you saying that 99% of hazardous nuclear material is consumed in its own process? What does 'fissioned' mean in this context? Also can you comment on whether this requires more or less uranium ore inputs than prior generation reactors?
"Fissioned" in any nuclear context means big atoms are split into small atoms.
Natural uranium is 0.7% U235, and the rest U238. Only the U235 is fissionable by the slow neutrons in conventional reactors. For a nuclear plant, we have to enrich the uranium until it's at least 2% U235 (or a little more, depending on reactor design...the top is about 5%).
The U238 in the reactor doesn't fission when hit by a neutron, but may absorb it and turn into plutonium, which is fissionable. About a third of a conventional reactor's energy output comes from fissioning plutonium.
Other transuranics (elements heavier than uranium) are also produced in a conventional reactor as nuclei absorb neutrons without fissioning. The end product is a mixture of U238, unfissioned U235 and plutonium, other transuranics, and fission products. There's some fissionable material left over because some fission products absorb neutrons, poisoning the reaction; some countries, like France, "reprocess" this mixture to pull out the remaining fissionables.
A fast reactor changes all this. In a conventional reactor, neutrons are purposely slowed down by materials like graphite and water. In a fast reactor, the neutrons from fission are left at the high energies they start with. These neutrons can fission U238 and all the transuranics.
So the fast reactor can use all of the uranium, instead of just 1% percent of it (U235 plus some U238 that gets converted to plutonium). That does mean it only needs about 1% as much uranium input.
A 1 GW coal plant uses a 100-car trainload of fuel every three days. A conventional nuclear plant uses an 18-wheeler load of fuel rods every 18 months. But a 1GW fast reactor uses just one ton of fuel per year, about the size of a beach ball. It can supply all the energy you need for your entire life, transportation included, from a piece of fuel the size of a golfball.
Small point - we replaced about a third of the fuel each refueling. That is about 70 fuel assemblies. If memory serves me right there were about 10 or so assemblies per truck. The are shipped in large, accident proof, casks and each assembly is individually packed. They take up a lot of room.
This is very helpful, thank you and I hope you continue to broadcast this message. It is definitely changing my thinking and I don't see major media outlets working to explain the technical advantages of these new technologies. It is, after all, a public outreach problem to get new sites approved.
It's amazing isn't it, a golfball sized material to power your life. Unfortunately, we again bump up against the problem of a single actor having too much power (literally). Sadly, someone will try to use their golfball to blow up a large city. We might have some amazing batteries otherwise. As is, I imagine we'll have to parcel out energy in small quantities to individuals.
It's not bomb-grade material. In fact, after startup the reactor can be fed by natural uranium, depleted uranium, or nuclear waste.
(And I'm not suggesting that individuals would get their own golfballs. I'm just pointing out the amount of material required to fuel each person's lifetime usage.)
>> ...just one ton of fuel per year, about the size of a beach ball.
Well, one hell of a hot beach ball. While the numbers are correct, that is how big one ton of uranium would be, for all practical purposes the fuel would be much bigger. The rods aren't 100% uranium. And they certainly aren't all transported in one spherical mass (boom). It would be moved a few kilos at a time, under escort. So there would still be lots of shipment/trucks transporting fuel to the reactor.
It won't be pallet delivered by fedex ground every other year.
For solid-fueled designs like the Integral Fast Reactor, the fuel is metallic uranium in steel-encased rods. For fast molten salt reactors, it's pretty much just pure fuel, since it gets melted into the liquid reactor fuel.
After startup, the fuel can be unenriched uranium, so there's no concern about an explosion, or any significant security concern. The only part that requires care and high security is the startup fuel, which has to be enriched to about 20% U235. (Bomb-grade is over 90%.)
Even so, the fuel isn't shipped in paper bags. It moves inside containers, insider other containers. If you saw it heading down the road on a truck it would be a much larger/heavier object.
I would still not recommend assembling a beachball-sized mass of any sort of uranium. It may not be critical, but you are heading in that direction. The local criticallity officer will not be happy. Even depleted uranium, the stuff once used in bullets, probably shouldn't be so assembled.
I read that an awful lot of it was fired into Iraq by the US in the last 'war' there, and will be causing birth defects there for a long time. I don't think someone reading the calm sentence Depleted uranium is still used in military large-caliber bullets would have any idea of the horrifying reality.
(Depleted) Uranium is a pyrophoric material - it spontaneously ignites in the right conditions (e.g. when it's shot at a tank and penetrates it), making a better job of killing said tank's occupants. This causes it to vaporize, and can now be breathed in - the exact set of circumstances where its nature of alpha emitter is dangerous for health.
While this is horrific, and I hope it stops, please keep in mind that any other use case which doesn't involve burning it or aerosolizing it creates no health hazard - you can build glassware with a high U content and drink from it.
any other use case which doesn't involve burning it or aerosolizing it creates no health hazard
That doesn't sound quite right:
"Normal functioning of the kidney, brain, liver, heart, and other systems can be affected by uranium exposure, because, besides being weakly radioactive, uranium is a toxic metal. Uranium is also a reproductive toxicant. ...Uranium metal is commonly handled with gloves..."
