APM and nuclear technology
- radiation damage (similar issues at very high temperatures refractory materials)
- nuclear fusion
- isotope separation (also for non radioactive isotopes)
- deep drilling for nuclear waste disposal (hiding?)
- usage in transmutation?
Radiation decontamination
Sadly we already have lots of reason to seriously think about this and it seems rather unlikely that the amount we have to cleanup wont grow any further.
Removal of highly dispersed radionucleotides deposited in complex and heterogeneous solid materials is a lot harder than removal of diluted atmospheric CO2. Advanced APM technology is not a magic wand that will magically solve all problems we create. This is one of the occasions where this should become fairly obvious.
Attempting cleanup with mobile nanobot like devices highly dispersed into a natural environment might be fighting evil with an even bigger evil. Relative to the contaminated mass only a small fraction of cleanup device mass is practical. Thus if at all possible cleanup devices must work fast and be pretty mobile to cleanup faster than the natural decay would. Especially the mobility aspect of the reproduction hexagon is violated and there is the danger of being unable to recollect the purposely spilled nanomachinery. Like with bad kinds of air using micro ships there's the possibility of toxicity for all lung breathing life forms. (spray paint and repeatedly airborne - bad; organic liquid bound and crawling - better??)
Withought weighing an atom it is impossible to determine whether it will decay or not.
Radiation contaminated soil and porous concrete and the like are complex materials.
They can't be simply systematically sieved through for radioactive atoms.
One could attempt to cut out micro sized pieces, evaporate them in hermetically sealed micro-chambers and try to catch only those elements that make the most trouble
like e.g. calcium test their mass and sieve them out if they're radionucleotides. (This is related to the recycling of slack problem. The more elements of the periodic table one is able to handle the better this works.)
Such a form of cleanup amounts to complete thermal destruction of any structure that was there and would require tremendous amounts of energy.
One can't really avoid destroying way more than necessary since radiation detection devices (e.g. Geiger counters) can not be constructed in the nanometer size range (see: sensors). So one can only get a very rough idea where the radionucleotides are located and needs to cut out huge blocks (cubic centimeter) that need to be thermalized.
Using chemicals to bind radionucleotides goes into the non mechanical technology path.
