Abstract:
The present invention provides a modular nuclear reactor system comprising a reactor pressure vessel having a lower section having a first wall and a second wall and an upper section having a first wall and a second wall. The reactor includes a chimney with an attached heat exchanger. First and second passageways create a circulation loop wherein heated heat transfer fluid circulates up from the reactor core, through the chimney, through an upper plenum and downwardly past the heat exchanger, into a lower plenum and back into the core.