BWR type reactors

Purpose: To enable to scatter spray water uniformly to the reactor core and facilitate the scattering of the spray water toward the center of the reactor core upon loss of coolant accidents. Constitution: A shroud head of a reactor core planted with stand pipes of a reactor core is made flat and the height of the shroud head is made greater at the periphery of the reactor core. A space between the grid plate and the shroud head is made larger and reactor core spray spurgers are sposed at the upper portion of the shroud inner wall (near the end plate for the shroud head). It is appropriate that the spurger nozzles are set at the position from 0.75 m to 1.25 m from the upper end of the reactor core. (Horiuchi, T.)