Timeline for Spaceflight without transistors and nuclear power - how to bend the history of physics?
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Nov 13, 2017 at 23:43 | comment | added | Dan Mills | @PieterGeerkens That, plus the Israeli ("not a plutonium producer, honest gov") reactors were the ones I was thinking of when I mentioned heavy water moderation, also the German WW2 effort the Danish resistance sunk that ferry to stop. None of that works with U235/238 ratios very much lower then they are. | |
| Nov 13, 2017 at 22:50 | comment | added | Pieter Geerkens | @DanMills: Never heard of the Candu reactor. Use of heavy water coolant enables the use of unenriched uranium as fuel. | |
| Nov 13, 2017 at 11:57 | comment | added | Dan Mills | @NicolBolas That is decay heat (mainly from U238) not fission heating from the fission of U235, and U235 has a shorter half life the U238, so the longer you wait, the smaller proportion of natural uranium will be fissile. At the moment you can build a reactor that will run on natural uranium (If you make it large enough, heavy water and graphite moderators are both possible), at some point the concentration of U235 will fall far enough to make this no longer viable, any you need that first fission pile if you want to convert anything else fertile to a fissile material. | |
| Nov 13, 2017 at 4:26 | comment | added | talex | There is other semiconductor except Si based. | |
| Nov 12, 2017 at 23:39 | comment | added | Nicol Bolas | "Just make life developing on the planet take a few billion years longer then it did, the U235 will be largely gone, and without that bootstrapping a fission reactor is kind of tough." So... what keeps its core molten? Because as I understood, Earth's core has retained its molten state due in a significant degree to the decay of radioactive isotopes, particularly uranium. | |
| Nov 12, 2017 at 19:15 | history | answered | Dan Mills | CC BY-SA 3.0 |