Gen, so the implication would be that weapons production was the #1 choice when deciding which path to take? I'm cynical enough to admit that this would be an important factor, maybe even the most important, but surely there are other things that contributed. Plus the breeder reactors would be involved in the solution anyways, and they could still be used for weaponization.

I'm specifically interested in the engineering problems. I don't know enough about this tech to know what the down sides are. There must be some serious "cons" here, even though the "pros" sure like they should win out. How do you make pipes that won't corrode when filled with molten salts for a few decades? Even the tiniest bit of water getting in would be...bad. What about the fact that they engineers at Oak Ridge probably have mostly passed away by now. Do we need to re-learn and re-verify everything that they did, or has ongoing research proceeded without a large gap?