Methods of moving an induction coil to move a control element in a nuclear reactor

{
  "publication_number": "US11728050B2",
  "country": "US",
  "kind": "B2",
  "title": "Methods of moving an induction coil to move a control element in a nuclear reactor",
  "abstract": "Control rod drives include linearly-moveable control elements inside an isolation barrier. Control rod drives move the control element through secured magnetic elements subject to magnetic fields. Induction coils may generate magnetic fields and be moveable across a full stroke length of the control element in the reactor. A motor may spin a linear screw to move the induction coils on a vertical travel nut. A control rod assembly may house the magnetic elements and directly, removably join to the control element. The control rod assembly may lock with magnetic overtravel latches inside the isolation barrier to maintain an overtravel position. Overtravel release coils outside the isolation barrier may release the latches to leave the overtravel position. Operation includes moving the induction coils with a linear screw to drive the control element to desired insertion points, including full insertion by gravity following de-energization. No direct connection may penetrate the isolation barrier.",
  "claims": [
    "1. A method of moving a control element in a nuclear reactor, the method comprising: moving an induction coil outside of an isolation barrier and in a vacuum environment, wherein the moving drives a magnet secured to the control element, wherein the magnet and the control element are inside of the isolation barrier and in a pressurized reactor environment such that the control element linearly moves inside the isolation barrier exactly with the induction coil.",
    "2. The method of claim 1, further comprising: energizing the induction coil before the moving the induction coil.",
    "3. The method of claim 2, further comprising: de-energizing the induction coil to drive the control element by gravity into a reactor.",
    "4. The method of claim 1, wherein the control rod drive includes a control rod assembly secured to the control element, and wherein the control rod assembly includes the magnet.",
    "5. The method of claim 1, wherein the induction coil and the isolation barrier are sealed inside a housing, and wherein the housing is configured to maintain a vacuum outside the isolation barrier.",
    "6. The method of claim 1, further comprising: moving the induction coil to drive the control element to an overtravel position completely withdrawn from a reactor, wherein a plurality of magnetic overdrive latches engage a control rod assembly directly connected to the control element, wherein the engaging occurs when the control element is at the overtravel position, wherein the control element, the control rod assembly, and the plurality of magnetic overdrive latches are inside the isolation barrier.",
    "7. The method of claim 6, further comprising: removing the control element from the control rod assembly, wherein the control element is at the overtravel position during the removing.",
    "8. The method of claim 6, further comprising: energizing a plurality of overtravel induction coils to release the magnetic overdrive latches to disengage the control rod assembly, wherein the plurality of overtravel induction coils are outside the isolation barrier.",
    "9. The method of claim 1, wherein the moving includes energizing a motor to rotate a linear screw to which the induction coil is connected.",
    "10. The method of claim 9, wherein the induction coil is mounted on a vertical travel nut to move in a vertical distance as the linear screw rotates.",
    "11. A method of moving a control element in a nuclear reactor, the method comprising: moving an induction coil outside of an isolation barrier, wherein the moving drives a magnet secured to the control element, wherein the control element and the magnet are inside of the isolation barrier such that the control element linearly moves inside the isolation barrier exactly with the induction coil, wherein the induction coil and the isolation barrier are sealed inside a housing, and wherein the housing is configured to maintain a vacuum outside the isolation barrier.",
    "12. The method of claim 11, wherein the induction coil is in a vacuum environment, and wherein the control element is in a pressurized reactor environment.",
    "13. The method of claim 11, further comprising: energizing the induction coil before the moving the induction coil.",
    "14. The method of claim 13, further comprising: de-energizing the induction coil to drive the control element by gravity into a reactor.",
    "15. The method of claim 11, wherein the control rod drive includes a control rod assembly secured to the control element, and wherein the control rod assembly includes the magnet.",
    "16. A method of moving a control element in a nuclear reactor, the method comprising: moving an induction coil outside of an isolation barrier, wherein the moving drives a magnet secured to the control element, wherein the control element and the magnet are inside of the isolation barrier such that the control element linearly moves inside the isolation barrier exactly with the induction coil; and moving the induction coil to drive the control element to an overtravel position completely withdrawn from a reactor, wherein a plurality of magnetic overdrive latches engage a control rod assembly directly connected to the control element at the overtravel position, wherein the control element, the control rod assembly, and the plurality of magnetic overdrive latches are inside the isolation barrier.",
    "17. The method of claim 16, wherein the induction coil is in a vacuum environment, and wherein the control element is in a pressurized reactor environment.",
    "18. The method of claim 16, further comprising: energizing the induction coil before the moving the induction coil.",
    "19. The method of claim 16, wherein the control rod drive includes a control rod assembly secured to the control element, and wherein the control rod assembly includes the magnet.",
    "20. The method of claim 16, further comprising: removing the control element from the control rod assembly, wherein the control element is at the overtravel position during the removing."
  ],
  "description_excerpt": "FIG. 1 is an illustration of a drive rod-control rod assembly (CRA) connection 10 useable with example embodiment control drives. In most conventional PWR control rod assemblies, drive rod 11 and actuating rod 12 extend in lateral support tube 16 from above a reactor pressure vessel 1 down to a lockable spud or bayonet 13 that joins to CRA 15 via locking plug 14. CRA 15 contains neutron absorbent materials what can be used to control a nuclear chain reaction based on an amount of vertical insertion. Control rods are driven from above by vertical movement of actuating rod 12 and drive rod 13, under force from the control rod drive mechanism.\n\nThe following documents are incorporated herein by reference in their entireties: US Pat Pub 2015/0255178 to Tsuchiya et al; U.S. Pat. No. 4,423,002 to Wiart et al.; U.S. Pat. No. 4,369,161 to Martin; U.S. Pat. No. 4,338,159 to Martin et al.; U.S. Pat. No. 4,044,622 to Matthews; U.S. Pat. No. 9,305,669 to Hyde et al.; U.S. Pat. No. 3,933,581 to McKeehan et al.; U.S. Pat. No. 4,048,010 to Eschenfelder et al.; U.S. Pat. No. 4,092,213 to Nishimura; U.S. Pat. No. 4,147,589 to Roman et al.; U.S. Pat. No. 4,288,898 to Adcock; U.S. Pat. No. 4,484,093 to Smith; U.S. Pat. No. 5,276,719 to Batheja; U.S. Pat. No. 8,915,161 to Akatsuka et al.; U.S. Pat. No. 4,518,559 to Fischer et al.; U.S. Pat. No. 5,517,536 to Goldberg et al.; U.S. Pat. No. 5,428,873 to Hitchcock et al.; U.S. Pat. No. 8,571,162 to Maruyama et al.; U.S. Pat. No. 8,757,065 to Fjerstad et al.; U.S. Pat. No. 5,778,034 to Tani; U.S. Pat. No. 9,336,910 to Shargots et al.; U.S. Pat. No. 3,941,653 to Thorp, II; U.S. Pat. No.",
  "cpc": [
    "G21C 7/14",
    "F16B 2001/0035",
    "F16B 2200/83",
    "G21C 13/02",
    "G21C 15/02",
    "G21C 17/10",
    "G21C 7/12",
    "G21C 9/02",
    "H01F 7/08",
    "H02K 41/02",
    "H02K 41/031",
    "H02K 7/116",
    "H02K 9/19",
    "Y02E 30/30"
  ],
  "ipc": [
    "F16B 1/00",
    "G21C 7/12",
    "G21C 7/14",
    "G21C 9/02"
  ],
  "assignees": [
    "GE Hitachi Nuclear Energy Americas LLC"
  ],
  "inventors": [
    "Kenneth A. Morgan",
    "David L. Major",
    "Randy M. Brown",
    "Gerald A. Deaver"
  ],
  "filing_date": "2020-11-30",
  "publication_date": "2023-08-15",
  "grant_date": "2023-08-15",
  "priority_date": "2016-07-13",
  "application_number": "US-202017107878-A",
  "family_id": "60941238",
  "cited_by_count": 0,
  "citations": [
    "US3566224A",
    "JPS57168192A",
    "JPS61215992A",
    "FR3016075A1",
    "US20160307652A1"
  ]
}