[0030] Spatially relative terms, such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. [0031] With reference to Figure 1, a boiling water nuclear reactor 10 includes a reactor pressure vessel 12 which supplies steam to a turbine 14 which drives an electricity generator 16. The steam from the turbine 14 is directed to a condenser system 18. Water from the condenser system 18 is returned to the reactor pressure vessel 12. The reactor pressure vessel 12 is divided radially into two basic areas so that the reactor core 20 is inside a shroud 22 so that downward flow in the downcomer 24 can be redirected upward through the reactor core 20. [0032] An isolation condenser system 30 is in communication with an isolation condenser system steam supply line 32. Condensate from the isolation condenser system is reintroduced into the reactor pressure vessel 12 during system shutdown.