I'm no expert on the topic, but I think you need essentially different tools and technology to reach the purity necessary for weapons. So using these way more expensive tools to create fuel would be just stupid.
They use exactly the same process and technology (these days either gas diffusion or gas centrifuge). These are iterative processes; you keep running them until you get the level of enrichment you want (<20% for fuel, >80% for weapons). Quit speculating on how you can get the answer you want and try the facts.
