There's a good article on Thorium reactors on Wikipedia that covers some of the unfortunate design decisions that led to the current reactors with the inherent risk of melt down and explosion ala Fukishima, etc., and the generation of lots of very "hot" waste. Both were avoidable.
Basically, the US military pressure for nuclear weapons grade plutonium guided the decision away from safer designs with much less and much shorter half life waste. The thorium fuel designed plant that was built in the 60's was operated for a number of years successfully. They fired the guy who ran it and openly promoted it's inherent melt-down proof design. Raising safety issues was not acceptable, we had bombs to build. He has been vindicated, in my mind.
https://en.wikipedia.org/wiki/Thorium-based_nuclear_powerThe present designs should never have been built in large numbers, and the continued work on safer (ala thorium or molten salt) designs should not have been abandoned AFTER being successful. CANDU was a step in the right direction but not nearly far enough. There is a difference between "safe if we don't hire Homer Simpson or have Mr Burns managing", and safe by inherent design, where at any time and with any number of failures, plant operators could walk away and there will not be melt down, explosion and contamination of the air and water. There will still be Homer Simpson type incidents, because all you can hire are humans, but sadly, there were well proven design approaches that would have prevented Fukishima.
So linking nuclear bombs to fission plants, while seemly irrational, is in fact what got us into this particular mess. And it does raise the issue as to the ability of our various regulatory agencies to be able to make good decisions for the public when real threats to public safety are present. Eisenhower tried to warn us about the excessive influence of the military industrial complex and this is a prime example of just that.
A key section from Wikipedia to get your interest up:
After World War II, uranium-based nuclear reactors were built to produce electricity. These were similar to the reactor designs that produced material for nuclear weapons. During that period, the government of the United States also built an experimental molten salt reactor using U-233 fuel, the fissile material created by bombarding thorium with neutrons. The MSRE reactor, built at Oak Ridge National Laboratory, operated critical for roughly 15,000 hours from 1965 to 1969. In 1968, Nobel laureate and discoverer of plutonium, Glenn Seaborg, publicly announced to the Atomic Energy Commission, of which he was chairman, that the thorium-based reactor had been successfully developed and tested.
In 1973, however, the US government settled on uranium technology and largely discontinued thorium-related nuclear research. The reasons were that uranium-fueled reactors were more efficient, the research was proven, and thorium's breeding ratio was thought insufficient to produce enough fuel to support development of a commercial nuclear industry. As Moir and Teller later wrote, "The competition came down to a liquid metal fast breeder reactor (LMFBR) on the uranium-plutonium cycle and a thermal reactor on the thorium-233U cycle, the molten salt breeder reactor. The LMFBR had a larger breeding rate ... and won the competition." In their opinion, the decision to stop development of thorium reactors, at least as a backup option, “was an excusable mistake.”[4]
Science writer Richard Martin states that nuclear physicist Alvin Weinberg, who was director at Oak Ridge and primarily responsible for the new reactor, lost his job as director because he championed development of the safer thorium reactors.[7][8] Weinberg himself recalls this period:
[Congressman] Chet Holifield was clearly exasperated with me, and he finally blurted out, "Alvin, if you are concerned about the safety of reactors, then I think it may be time for you to leave nuclear energy." I was speechless. But it was apparent to me that my style, my attitude, and my perception of the future were no longer in tune with the powers within the AEC.[9]
Martin explains that Weinberg's unwillingness to sacrifice potentially safe nuclear power for the benefit of military uses forced him to retire:
Weinberg realized that you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. . . . his team built a working reactor . . . . and he spent the rest of his 18-year tenure trying to make thorium the heart of the nation’s atomic power effort. He failed. Uranium reactors had already been established, and Hyman Rickover, de facto head of the US nuclear program, wanted the plutonium from uranium-powered nuclear plants to make bombs. Increasingly shunted aside, Weinberg was finally forced out in 1973.[10]
Despite the documented history of thorium nuclear power, many of today’s nuclear experts were nonetheless unaware of it. According to Chemical & Engineering News, "most people—including scientists—have hardly heard of the heavy-metal element and know little about it...," noting a comment by a conference attendee that "it's possible to have a Ph.D. in nuclear reactor technology and not know about thorium energy."[11] Nuclear physicist Victor J. Stenger, for one, first learned of it in 2012:
It came as a surprise to me to learn recently that such an alternative has been available to us since World War II, but not pursued because it lacked weapons applications.[12]
Others, including former NASA scientist and thorium expert Kirk Sorensen, agree that "thorium was the alternative path that was not taken … "[13][14]:2 According to Sorensen, during a documentary interview, he states that if the US had not discontinued its research in 1974 it could have "probably achieved energy independence by around 2000."[15]