Core barrel support system for nuclear reactors

A nuclear reactor is described having a pressure vessel and a core barrel having a bottom core support plate situated within the pressure vessel, the core support plate engaged about the periphery thereof by engagement means, which have a recess therein for engagement with a key. The core support plate has apertures therethrough one of which communicates with each recess of the engagement means, wherein a circular wall is provided in the core support plate about the apertures; and a key insertable into and positioned in the apertures in a secure relationship. The key having a lower section thereof of a rectangular cross-section which extends into the recess of the engagement means. The apertures of the core support plate being alignable with the engagement means of the pressure vessel and the keys being securable in the apertures of the core support plate and the recess of the engagement means from above the core support plate