Nuclear reactor internal structure

摘要

A nuclear reactor internal structure is provided wherein generation and promotion of object-downstream separating vortices are suppressed so that coolant (1) uniformly flows in a reactor core and pressure loss of flow of the coolant (1) is reduced so that the flow of the coolant (1) is stabilized. A lower connecting plate (30) arranged in a lower plenum (8) comprises a ring portion, in which an arcuate portion and a cut-off portion are alternately formed. An outer peripheral portion of the ring portion is asymmetric relative to a flow direction of main flow and also asymmetric relative to a separating flow generation direction. Also, a nuclear reactor internal structure comprising pumps connected to a coolant inlet nozzle (3), which have discharge flow rate performances different from each other, a flow guide (231, 241) arranged in a bottom portion of the lower plenum (8) and/or a radial connection portion of which outer peripheral portion is formed in a streamlined shape, is provided.