Molten Salt and Pebble Beds and Breeders, Oh My! Alternative Reactor Designs (Part I)
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- čas přidán 23. 03. 2021
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To celebrate the channel's 1-year anniversary, I cover a subject many of you have been asking for: unusual nuclear reactor designs.
In Part I, we look at the history of fast breeder reactors, which held a great promise in the 1950s but due to various technical, economic, and political factors were largely superseded by more conventional PWR and BWR designs.
Exceptional content !!!! 5 Stars and my gratitude!
Here for the pebble beds....maybe next time 😂
So much interesting information here. I had no idea there was a solid-fuelled Thorium-Uranium reactor operating. I only knew about the MSRE, but as you know that never had the Thorium blanket actually installed.
China's now got TMSR-LF1 running on 50kg thorium (First to operate, there are others working on it) using a 20% U235 kickstart in a single loop (It's more or less a rebuild of the MSRE to verify ORNL's work)
Thank you for this clear explanation of the past and present situation. The main reason for not developing the Thorium Molten Salt reactor is most likely the influence from the oil and coal companies, both producing the most pollution in the world. They see this development as a threat to their business. And the many people who work in those industries and the shareholders will do everything in their power to stop or at least slow down this development.
Great video ! Lots of precious information! And first time I hear an English speaker say Super Phoenix with the correct pronunciation in French haha
Thank you! I am a fluent French speaker (my written French is less well-practiced), so I make an effort to pronounce French words correctly :P
One thing to note. Pu-239 is the only nuclear proliferation threat (EDIT: from breeder reactors at least, normal enrichment of U-235 is always a threat). Many test warheads have been made and detonated with U-233, however due to U-233's high spontaneous fission rate, any warhead thus constructed will start the chain reaction before the proper level of compression of the core has been achieved, therefore it will have a low nuclear yield and waste most of the explosives energy in distributing the fissile material around ground zero, rather than properly compressing and initiating the fission reaction that results in the majority of the explosive yield of a nuclear warhead.
No known pit implosion scheme can cause U-233 to obtain a high yield nuclear explosion.
All that happens is you make a hard to clean up mess, you don't get the big kaboom.
Even with plutonium the breeder has to run a short cycle to keep Pu240 production to a minimum if a bomb is desired. For reactor use Pu240 is less a problem and a long breeding cycle, more time between switching out and reprocessing fertile fuel elements, can be used. In short, a breeder reactor can't produce bomb material without a recognizable change in operating practice.
U233 isn't the issue in U233 bombs, but the U232 which comes along for the ride _IS_ and as you've stated, the resuits have been pretty rotten with the best achievement being a 60% yield reduction in a 50:50 U233/Plutonium mix bomb and most of the rest barely exceeding "fizzle" status
The U232 is useful - it and its daughter products are such hot gamma emitters that they make trying to weaponise anything derived from thorium _extremely_ difficult (even using the much-vaunted Proactinium separation process of dual blanket designs) - and it's rather telling how violently several vested interests reject thorium/molten salt designs on the basis of "proliferation" whilst ignoring that enriched uranium is the WASTE PRODUCT of Pu239 production (which needs highly depleted uranium for best results) and as such there was lots of it kicking around looking for a home when Weinberg developed the Shippingport/Nautilus reactors - His explanation of using uranium over thorium was simply "Uranium isn't the best fuel, but it was the only thing available at the time"
If this was 1943 that would be true, but that hasn't been true since at least 1966. U-233 is an eminently suitable nuclear material and has been used successful in low and high yielded devices. It's abandonment was a result of Plutonium's issues being solved sooner, not because U-233s problems couldn't be or weren't solved.
@@gottjager760
I think you need a refresher on U-233's sponatneous fission rate.
15 april 1955 was when the US tested it's first and only bomb that used a hybrid Pu239/U233 fissile pit.
The yield was calculated at 33kt, but actual yield of the test was 22kt. This is not quite a fissile, but yields that are significantly under target are not something that lends confidence to the concept of using a bomb that has u-233 in it.
Plus the thorium fuel cycle does not generate the high-purity U233 you would need in a weapon anyways (which would have as little U232 as possible), which was my whole point.
@@44R0Ndin The spontaneous fission rate of U-233 is much lower than Pu-239, sufficiently low to allow it's use in gun type weapons. The Pu-232 contamination problem is the same as the Pu-240 contamination problem and like it was solved decades ago. Your point hasn't been true for the better part of a century.
Great video! Reprocessing and a closed fuel cycle is the only moral choice we have when it comes to nuclear power...
"...cooled by liquid mercury..." 😰
The best Reactor is the one that never gets built.
"breeders, oh my!" XD
@1:23: Said wrong thing: it's not Palladium, it's Protactinium. Th232 + n -> Th233 -> (beta + (Pa233 -> (beta + U233))).
Can we talk about the lack of PPE?
the technology that really killed the breeder reactors: the Zippe type. centrifuge enrichment was so much cheaper and simpler than gas diffusion and as noted resources of ore so plentiful, it just didn't make sense to bother anymore.
Interesting, but fast breeder reactors require highly-enriched uranium anyway for the seed fuel, so I don't think that easier enrichment would have affected breeders as much as plentiful uranium reserves.
classic case of moron thinking they know something and just drive-by commenting their word vomit@@CanadianMacGyver
The inventor of the PWR/BWR was Alvin Weinberger . As early as the 1950's he said "stop building these things". That is because there was already better and safer ways to do nuclear fission reactors. However, because the US Navy had done all the research and testing, private industry just adopted the military PWR/BWR design as a standard and pushed it as the ONLY way to do fission, which was foolish in the extreme. Solid fueled reactors are highly inefficient, and using water as coolant is a very bad idea, it is unstable in a high neutron flux environment, decomposing continuously into its component explosive gases and handles heat very poorly, requiring high pressures to operate above 100 centigrade. Molten Salt reactors were always the right path, and Thorium is useless for weapons, but ideal for making energy. Uranium is ideal for making weapons, but very poor at making power.......which do we want??
Urgh. This video is misleadingly labeled. It's really "Part 0: The context".