Added a mod setting for "maximum fuel value" to use when auto filling entities. If you set this to 100000000 (100 million, the value of Rocket Fuel) then you will no longer insert nuclear fuel (1.21 billion) and uranium fuel cells into entities.
Settings -> Mod Settings -> map.
Sorry for the long response on this one, I wasn't sure how I wanted to approach it, and this idea finally popped into my head.