Cylindrical refueling mast with longitudinal guide grooves

{
  "publication_number": "US5084231A",
  "country": "US",
  "kind": "A",
  "title": "Cylindrical refueling mast with longitudinal guide grooves",
  "abstract": "A refueling mast for a reactor complex includes four generally cylindrical tubes. Each inner tube has vertical grooved tracks formed therein. Each outer tube has a guide roller mounted thereon with grooves which mate with track grooves of a respective track on the adjacent inner tube. Track grooves are cold formed moving a roller die tool up and down each inner tube, while increasing pressure on the incorporated die rollers. This process flattens the inner tube where the tracks are being formed. The grooved tracks and the associated flattening provide the torsional rigidity required on the mast tubes for precise positioning and orientation of fuel elements.",
  "claims": [
    "1. A refueling mast for refueling a nuclear reactor, said mast comprising: plural longitudinally extending cylindrical tubes including an outermost tube and at least a first inner tube, said first tube having a first outer surface and being relatively dimensioned so that said inner tube can be slid within and relative to said outermost tube; said first inner tube having a first set of longitudinally extending tracks formed at said first outer surface, each of said tracks of said first set having longitudinally extending grooves; telescoping means for causing said first inner tube to slide within and relative to said outermost tube; and first guide means for guiding longitudinal movement of said first inner tube relative to said outermost tube, said first guide means including grooved rollers which mate with said first set of longitudinally extending tracks, said first guide means being mechanically coupled to said outermost tube so as to maintain a fixed longitudinal position relative thereto.",
    "2. A refueling mast as recited in claim 1 further comprising: a second inner tube, said second inner tube having a second outer surface and having a second set of longitudinally extending tracks formed at said second outer surface, each of said tracks of said second set having longitudinally extending grooves, each of said second set of tracks being radially aligned with a respective one of said set of tracks; and second guide means for guiding longitudinal movement of said second inner tube relative to said outermost tube, said second guide means including grooved rollers which mate with said second set of longitudinally extending tracks, said second guide means being mechanically coupled to an outer tube so as to maintain a fixed longitudinal position relative thereto.",
    "3. A refueling mast as recited in claim 1 wherein said first inner tube is flattened in the location of said tracks.",
    "4. A refueling system comprising: plural longitudinally extending cylindrical tubes including an outermost tube and plural inner tubes, said inner tubes including a first inner tube relatively dimensioned so that said first inner tube can be slid within and relative to said outermost tube, and a second inner tube relatively dimensioned so that said second inner tube can be slid within and relative to said first inner tube, said first inner tube having a first outer surface and said second inner tube having a second outer surface; said first inner tube having a first set of longitudinally extending tracks formed therein at said first outer surface; said second inner tube having a second set of longitudinally extending tracks formed therein at said second outer surface, each of said tracks of said first and second sets having longitudinally extending grooves, each of said second set of tracks being radially aligned with a respective one of said first set of tracks; hoist means for causing each inner tube to move within and relative the next radially outward and adjacent of said tubes; guide means for guiding longitudinal movement of each of said inner tubes, said guide means for each of said inner tubes including grooved rollers mounted on the next radially outward and adjacent of said tubes, each of said grooved rollers mating with a respective one of said grooved tracks; a fuel grapple attached to one of said inner tubes, said fuel grapple being adapted for engaging and lifting fuel elements; and transit means for moving said tubes laterally; whereby said hoist means can cause said inner tubes to protract and retract relative to said outermost tube so as to raise and lower said fuel grapple, said transit means providing for movement of fuel elements between a storage area and a reactor core in a fission reactor complex.",
    "5. The assembly of claim 4 wherein said inner tubes are flattened in the location of said tracks."
  ],
  "description_excerpt": "The present invention relates to fission reactors and, more particularly, to a refueling mast for a fission reactor. A major objective of the present invention is to provide a refueling mast which is suitable for a boiling water reactor and which is both economical and durable.\n\nNuclear fission reactors promise to provide abundant energy with far less strain on the environment than fossil fuels. However, since fissionable fuels are hazardous materials, great care must be taken in their transit. This care is especially important within a reactor complex, where fuel elements are transferred between storage area and reactor core. The transfer must be mechanized so that operators are not exposed to radiation.\n\nIn some boiling water reactor complexes, fuel elements are in the form of rods which are inserted into a core where the heat-generating fission reaction takes place. Spent fuel elements are transferred to a storage area and fresh fuel elements are transferred from the storage area to the core. The reactor core is situated in a reactor vessel and submersed in water which is circulated to provide for heat transfer. The storage area is also submersed in water in a separate tank, in part because water shields radiation emitted from a fuel element. Typically, the storage tank and the reactor vessel are separated by a barrier, e.g., of concrete.\n\nTransfer of fuel elements can be effected using a trolley, a movable bridge which is moved along tracks and spans the region including the reactor vessel and the storage area.",
  "cpc": [
    "G21C 19/16",
    "Y02E 30/30"
  ],
  "ipc": [
    "G21C 19/16",
    "G21C 19/18"
  ],
  "assignees": [
    "General Electric Co"
  ],
  "inventors": [
    "Robert C. Dixon",
    "James R. Punches",
    "David L. Rousar",
    "David L. Faulstich"
  ],
  "filing_date": "1989-07-31",
  "publication_date": "1992-01-28",
  "grant_date": "1992-01-28",
  "priority_date": "1989-07-31",
  "application_number": "US-38817589-A",
  "family_id": "23533000",
  "cited_by_count": 9,
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  ]
}