I want to produce fissile material.
I want to produce a lot of fissile material.
Fortunately, I read the Wikipedia page on Ted Taylor. It states that:
Apart from bombs, Taylor also explored concepts of producing large amounts of nuclear fuel in an expedited manner. His plans, known as MICE (Megaton Ice Contained Explosions), essentially sought to plant a thermonuclear weapon deep in the ice and detonate it, resulting in a giant underground pool of radioactive materials that could then be retrieved. While his idea had merit, Taylor ultimately received little support for this concept and the project never came to fruition.
This idea got me thinking. Nuclear weapons produce some level of neutron radiation, so, presumably, said neutron radiation can make valuable fissile material/nuclear fuel out of the following materials:
However, nuclear weapons are extremely powerful , and megaton-level explosions will damage the above materials if they're too close to said explosions, rendering them non-harvestable, so, instead of a megaton-level explosive, I'm going to use a ton-level explosive: the American W54 tactical nuclear warhead, which, in the specific configuration it's in in the Special Atomic Demolition Munition, has a yield of 10 tons of TNT. The W54 was used in the Davy Crockett nuclear recoilless rifle system due to its ability to neutron-activate the hulls of tanks - specifically, Soviet ones passing through the Fulda Gap. As such, I believe that it has a relatively low blast yield relative to its ability to emit neutron radiation.
I am going to place it into an arbitrarily large ice block and then detonate it. Said ice block is laced with solid chunks of both lithium-6 and uranium-238 that are a certain distance from the warhead. I shall call it N.I.C.E. - Nuclear Ice Contained Explosions, as a sort of miniature version of M.I.C.E.
The question: how far away from the detonation should these materials be placed to avoid being destroyed by the detonation? NUKEMAP says at least 10 meters, since the nuclear fireball of a 10-ton-of-TNT-level nuclear detonation is that size, and will vaporize anything within itself; however, thermal and pressure effects outside of that are harder to calculate, and I'd rather have the lithium-6 and uranium-238 as close to the bomb as possible, so as to maximize the neutron flux applied to them.
Note that there will be a solid layer of ice between the bomb and these materials, whose thickness will be equivalent to the distance between them and the bomb - so as to ensure that they aren't melted by the bomb's non-fireball heat effects.
I don't particularly care if this is practical. I just want it to happen, story-wise. Perhaps the people doing it are on an orbital habitat with no fissile materials and one tiny (relatively speaking), W54-sized nuclear bomb as their only neutron source.