Patent Number: 
Section: claims

1. A system for refueling a nuclear reactor, comprising:a lower reactor vessel comprising a plurality of fuel rods and a plurality of control rods disposed therein, the lower reactor vessel further comprising an upper flange;an upper reactor vessel comprising a steam generator and pressurizer disposed therein, the upper reactor vessel further comprising a lower flange that matingly engages the upper flange of the lower reactor vessel; anda transporter surrounding an outer surface of the upper reactor vessel, wherein the transporter includes a collar surrounding the outer surface of the upper reactor vessel, the collar including first and second wheels affixed thereto that are disposed upon respective first and second horizontal tracks, the first and second horizontal tracks being parallel to each other, andone or more of hydraulically-operated and electrically-operated lifts, each lift being secured to the collar and extendable upwardly to engage the upper reactor vessel and translate the upper reactor vessel vertically toward or away from the lower reactor vessel, and the transporter translates the upper reactor vessel horizontally toward or away from vertical alignment with the lower reactor vessel. 2. The system of claim 1, wherein the upper reactor vessel comprises an upper flange disposed concentrically around the outer surface thereof, wherein the upper flange of the upper reactor vessel is disposed below the pressurizer, wherein the one or more lifts are extendable upwardly to engage the upper flange of the upper reactor vessel to urge the upper reactor vessel vertically with respect to the lower reactor vessel when the transporter translates vertically. 3. The system of claim 1, wherein the collar further comprises third and fourth wheels that are disposed upon the first and second tracks, respectively, and with a spacing between the first and third wheels is equal to a spacing between the second and fourth wheels. 4. The system of claim 1, further comprising a plurality of vertical support members fixed to the collar and disposed in a mutually spaced relationship around the outer surface of the upper reactor vessel. 5. The system of claim 4, wherein the plurality of vertical support members collectively support a plurality of platforms arranged in a vertical spaced-apart fashion, each of the plurality of platforms extend around the outer surface of the upper reactor vessel. 6. The system of claim 4, wherein each of the vertical support members are configured to be translated with the collar. 7. The system of claim 1, wherein the transporter comprises horizontal first and second crane members, each of the first and second horizontal crane members are rollably mounted upon respective first and second horizontal tracks on opposite ends of the crane member, wherein the first and second horizontal tracks are aligned on opposite sides of the upper reactor vessel, and the first and second crane members collectively support first and second cross members disposed upon opposite sides of the upper reactor vessel. 8. The system of claim 1, wherein the plurality of control rods are configured to reciprocate axially with respect to the lower reactor vessel. 9. A method, comprising:providing a nuclear reactor primary plant within a stationary lower reactor vessel that encloses a plurality of fuel rods and a plurality of control rods, the lower reactor vessel comprising an open top defined by a first flange,providing a movable upper reactor vessel that encloses a steam generator and a pressurizer, the upper reactor vessel comprising an open bottom defined by a second flange that matingly engages the first flange during normal operation of the nuclear reactor,providing an upper reactor vessel transporter that surrounds the upper reactor vessel, the transporter comprising a collar surrounding an outer surface of the upper reactor vessel, the transporter further comprising at least first and second sets of wheels affixed to the collar that are mounted upon respective first and second horizontal tracks that are both disposed upon opposite sides of the upper reactor vessel and are parallel to each other, andproviding one or more lifts secured to the collar, wherein extension of the plurality of lifts upwardly causes engagement with the upper reactor vessel and urges the reactor vessel upwardly with respect to the lower reactor vessel. 10. The method of claim 9, further comprising providing a plurality of vertical support members fixed to the collar and spaced apart around the upper reactor vessel, wherein the plurality of vertical support members collectively support a plurality of platforms arranged in a vertical spaced-apart fashion, the platforms each extend around the outer surface of the upper reactor vessel. 11. A method of refueling a nuclear reactor, comprising:shutting down and cooling down the nuclear reactor, the nuclear reactor comprising a reactor vessel and steam system and a feedwater system;removing decay heat from the nuclear reactor;isolating the reactor vessel from the steam system and the feedwater system connected to the nuclear reactor during normal operation of the nuclear reactor;disconnecting a lower reactor vessel enclosing nuclear fuel and a plurality of control rods from an upper reactor vessel enclosing a steam generator and pressurizer disposed above the lower reactor vessel; andlifting the upper reactor vessel upwardly from the lower reactor vessel and sliding the upper reactor vessel away from the lower reactor vessel, to allow access to the lower reactor vessel to remove old nuclear fuel and/or add new nuclear fuel, wherein the upper reactor vessel is surrounded by a transporter, the transporter including a collar that surrounds the upper reactor vessel and being rollably connected to first and second parallel rails disposed upon opposite sides of the upper reactor vessel by one or more wheels that are secured to the collar, and the transporter further comprises one or more lifts that secured to the collar are extendable upwardly to engage the upper reactor vessel to upwardly translate the upper reactor vessel upwardly away from the lower reactor vessel.