A tale of lost WW2 uranium cubes shows why Germany’s nuclear program failed

https://arstechnica.com/science/2019/06/physicists-hunt-uranium-cubes-to-shed-light-on-germanys-failed-nuclear-reactor/

by Tomte • 7 years ago

49 16 7 years ago

So Germany's secretive, isolationist approach actually hampered their nuclear program, because the two groups weren't sharing information or resources.

I don't think that this is a problem thar is already solved in researches. Just my humble experience, but seems that very few projects involve coordination of groups. It's more likely to share small fragments of each group findings, only when the group is ahead of what is being published/revealed.

Even when you are inside the same organization, you are competing for resources, promotions, glory, money, hand-shakes. And even when you aren't, the other group might be.

Personal achievements are above any other interest. To overcome that only great organization, with great people, spending time in non-technical matter.

dfrage3• 7 years ago

In this instance, you can factor in the sense of urgency, which the Germans lacked because they thought the problems would take many many years to solve, while the Allies increasingly knew how practical it was.

Heisenberg, the distinguished senior scientist who was basically running the whole affair to the extent that was true, was a great theoretician, "the first quantum mechanical mind" per Jeremy Bernstein, author of Hitler's Uranium Club: The Secret Recordings at Farm Hall of 10 German scientists captured by Project Alsos, but was awful with numbers, let alone experiments (Fermi was the only top mind of the period great at both). It's in fact a very good thing his reactor didn't go critical, because for some reason he though the reaction would be self-regulating....

Whereas on the other side the concept of an atom bomb of modest size through fast neutron fissioning was realized very early by Otto Frisch and Rudolf Peierls, authors of the critical document on the topic published in March 1940 (https://en.wikipedia.org/wiki/Frisch%E2%80%93Peierls_memoran...). While they underestimated the amount of pure U235 needed, they were in the right ballpark, something that took the Germans at Farm Hall several rounds after Hiroshima to start approaching.

Another critical scientific error was not trying hard enough with graphite, which required purification way beyond the industrial state of the art to get rid of enough neutron poisons. Resulting on a total dependence on heavy water, which the Allies were able to thoroughly sabotage.

Organizationally, I think it was Rhodes who observed that it was not probable that wartime Germany would develop a bomb, or peacetime America. And if you're interested in that, read up on Lieutenant General Leslie Groves, without the extraordinarily good leadership he provided the Manhattan Project wouldn't have finished by the time we'd conquered Japan with liberal use of chemical weapons.

everyone• 7 years ago

"while we increasingly knew how practical it was"

Whose we?

duxup2• 7 years ago

I remember reading about the Soviet era space program and that to some extent it's speed and efficiency was credited to the program's leadership that in spite of the system were able to convince or compel (by pulling the appropriate levers of government) various groups to work together who otherwise really didn't have any reason to do so. However that didn't last forever and the program started to stall.

It seems to be a universal problem.

ethbro• 7 years ago

program's leadership

Sergei Korolev

https://en.wikipedia.org/wiki/Sergei_Korolev

effie• 7 years ago

There is a solution to this universal problem: strong military supervision and strong aligned incentives of the workers to cooperate (serving the country, avoiding gulag); see american and soviet nuclear bomb projects. In case of soviet space program, this worked too, soviets had a lot of success, only the american program was more successful in the later years. It would be interesting to see some analysis why that was - was it more powerful country economy, or better organizational patterns in the program?

JoeDaDude• 7 years ago

Now that we are on the lookout for the remaining missing cubes, perhaps they will show up on eBay, just like the (unused) graphite block for a Chernobyl type reactor:

https://www.ebay.com/itm/original-Soviet-USSR-Chernobyl-nucl...

read_if_gay_• 7 years ago

Archive link? It's 404 on ebay.

StreamBright• 7 years ago

https://logout.hu/bejegyzes/lauda/original_soviet_ussr_chern...

WillPostForFood• 7 years ago

The cubes are only slightly radioactive and don't pose a health concern, according to Koeth. Since uranium is so dense, "It winds up shielding itself," he said. "The radiation you measure from it is only coming from the surface."

Interesting, and answered the first question the popped into my mind when hearing about uranium cubes: are they dangerous?

acidburnNSA• 7 years ago

It's moreso that the half-life of both natural uranium isotopes is very long; billions of years. When something has a very long half-life, it emits fewer energetic particles per second, and inflicts lower dose (energy deposited), and therefore lower health risk.

All the daughter products are in secular equilibrium and so are also "rate limited".

When you split uranium nuclei in nuclear chain reactors, many of the resulting "half-uranium" fission products are neutron rich, and have very short half-lives. They quickly decay towards stability and along the way shoot out lots of radiation very quickly. This is high-level nuclear material and is dangerous.

IlegCowcat• 7 years ago

I have one very old uranium crystalware specimen sitting here - been in family for ages - it's awfully beautiful looking and our deep-blue LED christmas lights actually make it glow eerie.

The deeper-blue (indigo) LEDs reach into the wavelengths that the uranium glass glows at!

A tale of lost WW2 uranium cubes shows why Germany’s nuclear program failed

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