I know this might be too much as its a suggestion of a new natural resource "LEAD" but handling radioactive waste and material is very unfair in matters of transporting the items... You have to limit your builds to be small enough and even "accept" a little raditation to your population...

So... Why not add lead to create lead shielded pipes, belts, train wagons, stations... Plus you can use lead for batteries, which will be a heavy usage, plus add batteries to maintenance 2 maybe as part of the "change batteries" from time to time, and adding to big trucks and electric trains as part of the receipt as well... Maybe is a bit too much but would ease the radiation issue while moving radioactive material. Not block 100% but maybe 90% and give a higher penalty if these materials are not handled properly.

Yeah, its sometimes a bit frustrating wehn trying to process large ammounts of plutonium.

Tho i'd be more for the idea of a specific sort of transport containment packaging facility, sort of like what the compacter does. So turn plutonium into contained plutonium. The same building could then unpack aswell, depending on recipe settings. We could just fit it on the exit/entree of the radioactive storage building.

To contain 1 plutonium we would then need 1 steel, 1 concrete slab and 1 depleted uranium (giving it some more usefulness). Depending to the radio activity we would need more materials. Steel: structural shell, Concrete: bulk shielding, Depleted uranium: gamma shield

I like the lead idea, it would bring an entire new resource supply chain that we could use for various other products. We could start with a shielding facility, and perhaps later consider a lead supply chain.