# 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. - **Patent:** US 11728052 - **Original title:** Fast spectrum molten chloride test reactors - **Owner:** Terra Power - **Granted:** 2023 - **Status:** Active - **Times cited:** 1 - **Field:** nuclear_energy, clean_energy, engineering, materials ## What it does 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 does NOT 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. ## Real-world examples 1. TerraPower's Molten Chloride Fast Reactor (MCFR) designs 2. Advanced nuclear reactor concepts 3. Next-generation nuclear power plant designs ## 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. ## Frequently asked questions ### What does TerraPower's Molten Salt Reactor with Internal Heat Exchangers cover? 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. ### Who owns patent US 11728052? Terra Power owns this patent, granted in 2023. ### When does this patent expire? This patent is expected to expire on July 28, 2041, when the invention enters the public domain. ### What is patent US 11728052 cited by? This patent has been cited by 1 later patents that build on its ideas. ### What problem does this patent solve? 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. ### What does this patent NOT cover? Molten salt reactors where the primary reactor vessel has openings or penetrations other than the top opening (Claim 1). **Full plain-English explainer:** https://patentbrief.org/patent/us/11728052/fast-spectrum-molten-chloride-test-reactors **Original patent:** https://patents.google.com/patent/US11728052 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How Nuclear Power Plants Reuse Fuel Between Multiple Reactors](https://patentbrief.org/patent/us/10818403/inter-module-fuel-shuffling) — This patent describes a method for nuclear power plants with several reactors to efficiently reuse partially used fuel by moving it between different reactor cores across multiple operating cycles. - [Using Gas Pressure to Safely Control Liquid Fuel Nuclear Reactors](https://patentbrief.org/patent/us/12073952/fail-safe-reactivity-compensation-method-for-a-nuclear-reactor) — This patent describes a method to control a nuclear reaction in liquid-fueled reactors by using gas pressure to adjust the amount of fuel solution in special pipes, ensuring the reactor always returns to a safe state if something goes wrong. - [How the First Nuclear Reactor Works](https://patentbrief.org/patent/us/2708656/nuclear-reactor-fermi-szilard) — The foundational 1955 patent by Enrico Fermi and Leo Szilard describing the design of the first nuclear reactor capable of a self-sustaining chain reaction. - [How Early Electromagnetic Pumps Moved Liquid Metal Using Magnetic Fields](https://patentbrief.org/patent/us/1647147/sound-on-film-talking-pictures) — A 1927 patent for a pump that uses electromagnetic forces to move conductive liquids without needing moving mechanical parts like pistons or impellers. - [How to Make Solar Troughs Catch More Sunlight at Their Ends](https://patentbrief.org/patent/us/8049150/solar-collector-with-end-modifications) — This patent describes adding special reflective extensions and caps to the ends of a single-axis tracking solar trough to capture more sunlight that would otherwise be lost, making the collector more efficient.