NUCLEAR REACTOR

摘要

A nuclear reactor with control-rod clusters (49) movable into and out of its core (27) has a calandria structure (39) above the area of movement of the control-rod clusters (49). The coolant flow from the core (27) remains axially upward in the area (37) of movement of the control-rod clusters (49). Radial coolant flow occurs only through the calandria (39) above the control-rod cluster guide structure. The calandria (39) has tubes (58) between upper and lower supports (56, 54) which receive the drive rods (101) for the control-rod clusters (49) so as to protect the drive rods (101) from the transverse flow of coolant within the calandria (39).