The industrial generator doesn't accept the following RTG pellets:

• Polonium-210
• Gold-198
• Lead-209
• Balefire-XXX
  

If this is intentional, I think these should be accepted by the Industrial generator anyway.

These pellets vary from mid-end game, and since the industrial generator isn't that effective in later stages of progression, this may keep it useful later on. Especially since the generator is somewhat expensive for what is not a very powerful generator.