Patent Number: 
Section: claims

1. A method for housing nuclear reactor modules within a nuclear reactor building, comprising:housing and operating the nuclear reactor modules in different reactor bays of the nuclear reactor building,wherein the nuclear reactor modules each comprise:a reactor pressure vessel;a lower reactor vessel removably attached to the reactor pressure vessel and configured to house a reactor core;a containment vessel encapsulating the reactor pressure vessel; anda lower containment head removable attached to the containment vessel and configured to house the lower reactor vessel head; andfor an individual nuclear reactor module:transporting the nuclear reactor module via a crane from a reactor bay to a first location at a refueling bay;disconnecting the lower containment head from the containment vessel while supporting the lower containment head at the first location at the refueling bay;transporting the containment vessel, the reactor pressure vessel, and the lower reactor vessel head to a second location at the refueling bay; anddisconnecting the lower reactor vessel head from the reactor pressure while supporting the lower reactor vessel head at the second location at the refueling bay. 2. The method of claim 1, wherein the crane moves on a rail that extends over the reactor bays and the refueling bay. 3. The method of claim 1, wherein for each individual nuclear reactor module, the nuclear reactor module is transported via the crane from the reactor bay to the first location at the refueling bay through a common passageway of the nuclear reactor building. 4. The method of claim 3, further comprising flooding the common passageway so the nuclear reactor module is at least partially submerged in water when transported from the reactor bay to the first location at the refueling bay. 5. The method of claim 1, further comprising, for each individual nuclear reactor module, transporting the containment vessel and the reactor pressure vessel away from the first and second locations while the lower containment head remains supported at the first location of the refueling bay, and the lower reactor vessel head remains supported at the second location of the refueling bay.