{
  "patent_number": "US 11417435",
  "country": "US",
  "title": "How a Nuclear Reactor's Rotating Drum Controls Power",
  "original_title": "Control drum for a mobile nuclear reactor",
  "summary": "This patent describes a rotating drum for nuclear reactors, especially mobile ones, that uses tubes filled with different materials to absorb or scatter neutrons, precisely controlling the reactor's power output.",
  "what_it_does": "This patent describes a specialized \"control drum\" designed for nuclear reactors, particularly mobile ones. The drum has an outer shell and an inner shell, with several tubes held in place by perforated baffle plates (Claim 1). Some tubes contain \"neutron absorbing material\" like boron or hafnium, which slow down or stop the nuclear reaction. Other tubes contain \"neutron scattering material\" like beryllium or graphite, which reflect neutrons back into the fuel, speeding up the reaction (Claim 1). A drive mechanism rotates the drum (Claim 5). By turning the drum, either the neutron-absorbing tubes or the neutron-scattering tubes can be positioned to face the nuclear fuel rods, allowing precise control over the reactor's power level (Claim 5). For example, if the reactor needs to reduce power, the drum rotates to expose the neutron-absorbing tubes to the fuel. If the drive mechanism fails, a torsional spring automatically rotates the drum to a \"fail-safe state\" where the neutron-absorbing tubes face the fuel, shutting down the reaction (Claim 6, 7).",
  "what_it_does_not_cover": [
    "Does not cover control methods that use only neutron absorbing materials without also including neutron scattering materials within the same control drum (Claim 1).",
    "Does not cover control drums where the tubes are not supported by baffle plates with perforations (Claim 1).",
    "Does not cover control drums that lack a specific fail-safe mechanism, such as a torsional spring, to automatically rotate to a neutron-absorbing position upon drive failure (Claim 6, 7).",
    "Does not cover control drums that are not designed for horizontal mounting in a reflector region (Claim 9).",
    "Does not cover control drums without a magnetic coupling between the drive shaft and the inner shell (Claim 5)."
  ],
  "filed": "2019-12-31",
  "granted": "2022-08-16",
  "expires": "2039-12-31",
  "status": "active",
  "holder": "GE Hitachi Nuclear Energy Americas",
  "holder_url": "https://patentbrief.org/company/ge-hitachi-nuclear-energy-americas",
  "inventors": [
    {
      "name": "Dennis Scott NELSON",
      "url": "https://patentbrief.org/inventor/dennis-scott-nelson"
    }
  ],
  "times_cited": 8,
  "tags": [
    "nuclear_energy",
    "mechanical",
    "materials",
    "energy",
    "aerospace"
  ],
  "abstract": "Various example embodiments are directed towards an improved control drum, as well as systems, apparatuses, and/or methods for operating a nuclear reactor with a plurality of improved control drums. The control drum includes an outer shell, an inner shell, a plurality of tubes, the plurality of tubes including at least one neutron absorbing tube and at least one neutron scattering tube, and at least one baffle plate arranged between the outer shell and the inner shell, the at least one baffle plate including a plurality of perforations, and at least one perforation of the plurality of perforations configured to support a tube of the plurality of tubes.",
  "url": "https://patentbrief.org/patent/us/11417435/control-drum-for-a-mobile-nuclear-reactor",
  "markdown_url": "https://patentbrief.org/patent/us/11417435/control-drum-for-a-mobile-nuclear-reactor/md",
  "google_patents_url": "https://patents.google.com/patent/US11417435",
  "relatedPatents": []
}