Transatomic Power

Reactor concept

• A planned capacity of 1250 MWth, converting this to 520 MWe of electricity. This is a conservative rating of 41.6% efficiency.
• Passive nuclear safety features: Fail safe freeze valve and drain tank and Control rods and neutron reflectors - also actively actuatable.
• Lithium fluoride fuel salt. This is a departure from the Molten-Salt Reactor Experiment, which used an admixture of beryllium fluoride in its salt to get beryllium's corrosion control and neutron-doubling effects. Transatomic claims that LiF can dissolve more fuel per unit of salt, compensating for LiF's lack of neutron-doubling and higher melting point. An additional issue is that to minimize tritium production, the salt's ratio of lithium 7 should be enhanced. Currently, Lithium 7 is produced only in small amounts, for calibrating mass spectrographs. A single reactor will require quantities on the order of several metric tonnes.
• Moderated by zirconium hydride, possibly also using lithium hydride and yttrium hydride. ZrH is corroded by molten LiF salt, but an admixture of YH in the moderator may form an anticorrosion barrier of yttrium lithium fluoride.
• The reactor's vat, piping, heat-exchangers and pumps are to be made of "Modified Hastelloy-N," a corrosion-resistant nickel-chromium alloy developed from experience with the Molten-Salt Reactor Experiment. There is no published operating experience using this alloy with LiF in a reactor core, and the salt's lack of a redox control component to manage corrosion increases the risk. Regulators may delay commercial deployment of Transatomic's reactor by up to two full refueling cycles to validate this choice. With the Transatomic reactor's long fuel-use cycle, this could take a decade, and pose commercial risks.