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Comment by hairytrog | Hacker News Reader

- there is waste, it's just shorter lived than fission waste and lower in quantity. The expectation is that fusion reactors will have to be regulated in almost exactly the same way as fission reactors because they are nuclear sites, with nuclear waste, and proliferation concerns.

- there is lot's of pre processing of the fuel to breed the Tritium in a molten salt blanket that surrounds the reactor and separating from the salt and then feeding it into the chamber

- there is plenty of fission and fusion fuel. Yes, there is more hydrogen around.

- tritium is used in nuclear weapons as a booster, to dramatically lower the amount of necessary fissile material - each fusion reactor is a fast neutron source, which means it can be used to make weapons grade materials. Conveniently, it has a breeding blanket for tritium, in which other fertile fuels can be place to make weapons material: proliferation concerns are a real problem for fusion

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- tritium is used in nuclear weapons as a booster

It is, but tritium is not put into bombs. Lithium is.

- proliferation concerns are a real problem for fusion

Unless all fissile materials are banned. It is very easy to check for the existence of fissile materials. If there were no legitimate, safe reasons to have any fissile materials in use on the planet, then a global ban on fissile materials is on the table. A treaty where every nation checks on the other is reasonable. It is hard to build a secret fusion reactor, just as its hard to build a secret uranium centrifuge.

It is, but tritium is not put into bombs. Lithium is.

Both are put into bombs.

The main concern when it comes to tritium supply, regards tritium used for boosting of fission charges. Both applications are crucially important, but fusion boosting appears to require significantly larger quantities of tritium. Tritium and deuterium for boosting are supplied to the weapon from an external reservoir (gas bottle) as part of the arming process of the weapon.

Since about 5.5% of existing tritium decays every year, the tritium assigned to each weapon must be regularly replenished. This is done by removing the weapon’s tritium reservoir and exchanging it with a newly refilled reservoir (5). Figure 1.3 shows what may be such a reservoir.

From Norwegian Defence Research Establishment report "Tritium production":

https://publications.ffi.no/nb/item/asset/dspace:6780/20-013...

Also see this Savannah River Site page about tritium supply for weapons:

https://www.srs.gov/general/programs/dp/index.htm

And for a deeper dive, this fascinating blog post:

"U.S. Tritium Production for the Nuclear Weapons Stockpile – Not Like the Old Days of the Cold War"

https://lynceans.org/all-posts/u-s-tritium-production-for-th...

You are both correct :) Tritium is used for boosting fission bombs, lithium (lithium 6/7 deuterides) as fusion fuel in thermonuclear bombs.

So interesting story about this.

We originally didn't know Lithium-7 would be useful in thermonuclear weapons. It was assumed that it would be inert and that only the Lithium-6 would react with neutrons from the fission primary and breed tritium for the fusion secondary.

Then we tested a bomb [0] and the yield on it was accidentally 2.5x greater than anticipated. So large, in fact, that it is still the largest bomb ever detonated by the USA. It turns out that Lithium-7 will also breed tritium if the neutrons are powerful enough, and emits an additional neutron to continue the reaction. Reactions that we might never have discovered (or probably not until later) if it hadn't been for this mistake.

The end result was a lot more fuel for the bomb, and the explosion was so large that many of the measuring instruments were vaporized. The large yield also contributed to a radiological disaster [1], which was then the inspiration for the original Godzilla [2].

Anyways, that's how a math/chemistry mistake lead to the most famous kaiju movie (series) of all time.

[0] https://en.wikipedia.org/wiki/Castle_Bravo

[1] https://en.wikipedia.org/wiki/Daigo_Fukury%C5%AB_Maru

[2] https://en.wikipedia.org/wiki/Godzilla_(1954_film)

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