Internal control rod drive for a BWR
AssigneeGeneral Electric Company
InventorsIrvin R. Kobsa, Charles W. Relf, John C. Carruth
Life of this patent
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Abstract
A hydraulically based control rod drive system that is contained within the pressure vessel is disclosed for positioning the control rods relative to fuel rods positioned in a nuclear core of a boiling water reactor. Hydraulic jacks mounted on an open grid located entirely within the pressure vessel at a position above the nuclear core are used to position the control rods. Suitable jack and grid structures, as well as a hydraulic control arrangements are described.
Claims21
A control rod drive for vertically positioning a control rod relative to fuel rods arranged in a fuel core of a nuclear reactor having a pressure vessel that contains said fuel core, comprising:
- a jack rod suitable for being coupled to the control rod;
- and
- a hydraulic jack positioned within said pressure vessel above said fuel core, said hydraulic jack being capable of lifting, lowering and holdings said jack rod to regulate the position of the control rod,
- wherein said jack comprises:
- a hydraulically operated holding mechanism having holders arranged to selectively engage said jack rod to hold said jack rod in place;
- and
- a hydraulically operated lifting mechanism having lifters arranged to selectively engage said jack rod and a lift cylinder arranged to lift said lifters and said jack rod therewith when said holders are disengaged and said lifters are engaged.
A control rod drive system for vertically positioning a plurality of control rods relative to a plurality of fuel rod bundles arranged in a fuel core of a nuclear reactor having a pressure vessel that contains said fuel core, comprising:
- an open grid mounted with said pressure vessel at a position above said fuel core, said grid comprising a plurality of mounting surfaces;
- a plurality of jack rods, each one of said jack rods being coupled to a corresponding one of said plurality of control rods;
- and
- a plurality of hydraulic jacks, each one of said hydraulic jacks being attached to said grid on a corresponding one of said plurality of mounting surfaces and comprising a hydraulically operated means for holding, lifting and lowering a corresponding one of said plurality of jack rods relative to said grid, wherein each hydraulic jack comprises:
- a hydraulically operated holding mechanism having holders arranged to selectively engage said jack rod to hold said jack rod in place;
- and
- a hydraulically operated lifting mechanism having lifters arranged to selectively engage said jack rod and a lift cylinder arranged to lift said lifters and said jack rod therewith when said holders are disengaged and said lifters are engaged.
A control rod drive for positioning a control rod relative to a plurality of fuel rods at any one of a plurality of axial positions along a vertical axis, including a first axial position whereat said control rod is located above and removed from in between said plurality of fuel rods and a second position whereat said control rod is inserted in between said plurality of fuel rods, comprising:
- a jack rod coupled to a top portion of said control rod, said jack rod having indexing means formed on a surface thereof;
- and
- hydraulically operated means for engaging said indexing means without lifting said jack rod in a first hydraulic state and for engaging said indexing means with lifting of said jack rod in a second hydraulic state.
A control rod drive for positioning a control rod relative to a plurality of fuel rods at any one of a plurality of axial positions along a vertical axis, including a first axial position whereat said control rod is located above and removed from in between said plurality of fuel rods and a second position whereat said control is inserted in between said plurality of fuel rods, comprising:
- a jack rod coupled to a top portion of said control rod, said jack rod having indexing means formed on a surface thereof;
- and
- first hydraulically operated engagement means for engaging said indexing means in a first hydraulic state and disengaging said indexing means in a second hydraulic state,
- wherein said jack rod is locked against displacement along said vertical axis when said first hydraulically operated engagement means engages said indexing means.
Dependencies are inferred from the claim text.