In my sibling comment, I calculate 600:1 fission:fusion, for the heavy water reactors they're talking about. (I think it could be somewhat better if it were a

In my sibling comment, I calculate 600:1 fission:fusion, for the heavy water reactors they're talking about. (I think it could be somewhat better if it were a fission reactor optimized for tritium, but I don't know the numbers for that. I think that would entail fast-neutron reactors with enriched ⁶Li blankets -- analagous to what the fusion reactors are planning to do).