"Hey, these guys had a pretty good idea. Let's go back to it."

Alvin Weinberg MSR Questions (2004). Youtube link

Dr Laurence Miller: One of the things that I considered was the choice between the liquid metal fast reactors and ...

Alvin Weinberg: [Interrupting] Excuse me. How do you increase the volume in here?

Dr Laurence Miller: You mentioned where did we go wrong. And one of your aims was the molten salt reactor and instead of that we went for the liquid metal reactor. Do you think that was a serious mistake?

Alvin Weinberg: Yes I think it was a mistake but, I guess, what I'm talking about goes much beyond the kind of reactor that we're going to build, or that will take over. Because no matter what kind of reactor you build, apprehensive members of the public, or Ralph Nader for that matter, will be able to use this confusion between phantom risk and real risk to scare people out of nuclear energy. So ... I think that that issue overrides the question of whether molten salt is better than liquid metal. I happen to think that molten salt is better than [liquid] metal.

Moderator: I have a follow-on question from cyberspace that we got by email right before today's colloquium and its related to Dr. Miller's question. This question comes from Kirk Sorensen who is with the NASA Marshall Space Flight Center and it has to do with the molten salt breeder reactor. He would like for you to comment on the inherent safety of the molten salt reactor and how we might be able to restart a molten salt reactor programme.

Alvin Weinberg: The molten salt people, who included most famous figures nuclear energy, in particular Eugene Wigner, are all dying off and once they're dead then I suppose you can reinitiate a program on molten salt. Are molten salts inherently safer than liquid metal fuel pin reactors? I think they are, as much as anything, because you don't have supercritical amounts of uranium involved in the system. You add uranium, bit by bit, as you need it because the material is molten. But I'm much impressed with the fact that, despite molten salt reactors having in a sense been a failure in that we don't have people building molten salt reactors now, the molten salt reactor experiment, which produced seven and a half megawatts of heat was one of the most important, and I must say brilliant achievements of the Oak Ridge National Laboratory. And I hope that, after I'm gone, people will look at the dusty books that were written on molten salts and will say "Hey, these guys had a pretty good idea. Let's go back to it."