13. A method of limiting power of a boiling water nuclear reactor system having a reactor pressure vessel, a reactor core disposed in the reactor pressure vessel, a core shroud surrounding the reactor core, a downcomer region disposed between an inner surface of the reactor pressure vessel and the core shroud a steam line connected to an upper end of the reactor pressure vessel and a condenser system that receives steam from the reactor pressure vessel, the method comprising: returning condensate from the condenser inside the core shroud above the reactor core into one or both of an upper plenum or chimney region of the core shroud. 14. The method according to claim 13, wherein the condenser system is an isolation condenser system. 15. The method according to claim 14, wherein the returning returns the condensate from the isolation condenser system through a condensate return line that returns the condensate inside the core shroud and that includes a split portion that returns condensate inside the downcomer region. 16. The method according to claim 13, further comprising: receiving, at the condenser system, the steam from the reactor pressure vessel via a turbine.