United States used to be the leader in Thorium usage. What happened?
The 40 MWe Peach Bottom HTR in the USA was a demonstration Thorium-fueled reactor that ran from 1967-74. and produced a total of 33 billion kWh.
The 330 MWe Fort St Vrain HTR in Colorado, USA, ran from 1976-89. Almost 25 tons of Thorium was used in fuel for the reactor.
A unique Thorium-fueled light water breeder reactor operated from 1977 to 1982 at Shippingport in the USA– it used uranium-233 and had a power output of 60 MWe.
However, after 10 years passed and billions invested, the U.S. Atomic Energy Commission abandoned thorium research, with uranium-fueled nuclear power becoming the standard. In the 1980s, commercial Thorium ventures failed, such as the Indian Point Unit 1 water reactor near New York City, because of the vast financial costs of going alone in a hostile regulatory environment, and fuel and equipment failures. By the 1990s, the US nuclear power industry had abandoned Thorium, partly because Thorium’s breeding ratio was thought insufficient to produce enough fuel for commercial industrialization.
After the Three Mile Island accident, Middletown, PA in 1979 there was a 30 plus year hiatus in building another nuclear plant, and Thorium was not on any politicians list of areas in which to invest scarce research funds.
Some research and development was still conducted, but it was more concentrated in protecting the U.S. leading position in monitoring and controlling existing nuclear technology. As a contrast even the Netherlands is developing a molten salt Thorium reactor.
Will the U.S. again show leadership?