TerraPower's Molten Salt Reactor with Internal Heat Exchangers

This patent describes a unique molten salt nuclear reactor design by TerraPower, featuring an open-topped vessel and integrated heat exchangers for efficient internal cooling and fuel circulation.

What it covers

This patent outlines a molten fuel salt nuclear reactor where the main vessel is open at the top but has no other openings, a design choice intended to simplify construction and enhance safety. Inside this vessel, a 'neutron reflector' surrounds the core where nuclear reactions occur. Above this core, several 'heat exchangers' are placed, acting like radiators to remove heat from the hot molten fuel salt. A 'flow guide assembly' with a 'draft tube' directs the hot fuel salt from the central core region, through the heat exchangers, and then down an 'annular downcomer duct' before it flows back into the central core region, creating a continuous cooling loop. For example, hot fuel salt from the core flows up, transfers its heat to a coolant in the shell-and-tube heat exchangers (Claim 5), then flows down the annular downcomer duct, and re-enters the core to be heated again.

What it doesn't cover

• —Molten salt reactors where the primary reactor vessel has openings or penetrations other than the top opening (Claim 1).
• —Reactor designs where the heat exchangers are located outside the main reactor vessel (Claim 1).
• —Circulation systems that do not use a 'draft tube' to separate the central reactor core volume from an 'annular downcomer duct' (Claim 1).
• —Reactors that do not circulate fuel salt from the reactor core volume, through heat exchangers, into a downcomer duct, and then back into the reactor core volume (Abstract).

The clever bit

The truly novel aspect is the integrated design where the entire primary circulation path, including the heat exchangers, is contained within an open-topped vessel that has no other penetrations. This simplifies the vessel's construction and potentially enhances safety by minimizing potential leak points.

Why it matters

Molten salt reactors (MSRs) represent a significant area of innovation in advanced nuclear energy, promising enhanced safety features and more efficient fuel utilization. TerraPower, the assignee, is a prominent developer in this field, with backing from Bill Gates. This patent contributes to the intellectual property foundation for developing modular, safer, and potentially more cost-effective nuclear power solutions.

Real-world examples

• 1.TerraPower's Molten Chloride Fast Reactor (MCFR) designs
• 2.Advanced nuclear reactor concepts
• 3.Next-generation nuclear power plant designs