General Atomics, Inc.

Alan M Baxter

Carmelo Rodriguez

Francesco Venneri

Robert W Schleicher

Hangbok Choi

Mike Fikani

Donald McEachern

Richard K Lane

A modular, nuclear waste conversion reactor that continuously produces usable energy while converting U-238 and/or other fertile waste materials to fissionable nuclides. The reactor has a highly uniform, self-controlled, core () with a decades-long life and does not require reactivity control mechanisms within the boundary of the active core during operation to retain adequate safety. The exemplary embodiment employs high-temperature helium coolant, a dual-segment () initial annular critical core, carbide fuel, a fission product gas collection system, ceramic cladding and structural internals to create a modular reactor design that economically produces energy over multiple generations of reactor cores with only minimum addition of fertile material from one generation to the next.

Modular nuclear fission waste conversion reactor

A method for transmuting spent fuel from a nuclear reactor includes the step of separating the waste into components including a driver fuel component and a transmutation fuel component. The driver fuel, which includes fissile materials such as Plutonium , is used to initiate a critical, fission reaction in a reactor. The transmutation fuel, which includes non-fissile transuranic isotopes, is transmuted by thermal neutrons generated during fission of the driver fuel. The system is designed to promote fission of the driver fuel and reduce neutron capture by the driver fuel. Reacted driver fuel is separated into transuranics and fission products using a dry cleanup process and the resulting transuranics are mixed with transmutation fuel and re-introduced into the reactor. Transmutation fuel from the reactor is introduced into a second reactor for further transmutation by neutrons generated using a proton beam and spallation target.

System and method for radioactive waste destruction

A transuranic transmuter includes a sealable steel housing having a window to allow a beam of protons to enter the housing and strike a spallation target, thereby generating fast neutrons. Conductive tubes holding minor actinides are positioned within the housing and at a distance from the spallation target. A graphite block is positioned within the housing to interpose the minor actinides between the graphite block and the spallation target. Plutonium and toxic fission products are positioned in recesses formed within the graphite block. Upon exposure to fast neutrons from the spallation target, the minor actinides transmute by either fission or neutron capture reactions into one or more stable, less radiotoxic isotopes. Some neutrons from the target pass through the moderator and subsequently transmute the plutonium and the toxic fission products into one or more stable, less radiotoxic isotopes.

Devices and methods for transmuting materials

Plutonium is effectively and economically rendered unsuitable for employment in a device for creating a nuclear detonation. Weapons-grade plutonium is made into ceramic fuel in the form of spheroids of submillimeter size, coated with multi-layer fission-product-retentive coatings and disposed in sealed fuel chambers in graphite block fuel elements. These elements are used to form a core for a modular helium-cooled high temperature nuclear reactor which is operated to efficiently generate power by causing the hot high pressure helium coolant to drive a gas turbine directly connected to an electrical generator, which nuclear fuel core has about a 3-year lifetime. Spent nuclear fuel elements are removed at the end of 3 years and shifted to form the core for an accelerator-driven helium-cooled reactor wherein a subcritical core of spent fuel elements is safely caused to effectively continuously fission by a neutron flux created by a Linac which bombards a lead target with a beam of high energy protons. At the end of 1 to 2 more years, more than 99% of the original Pu-239 has fissioned or been transmuted, and the isotope distribution of remaining plutonium renders it no longer useful for carrying out a nuclear detonation. Such fuel elements can be securely stored without reprocessing in simple metal canisters in a long-term repository.

Growing community of inventors

Los Alamos, NM, United States of America

Alan M Baxter