Moderation apparatus for coolant leakage

Purpose: To moderate the coolant leakage upon rupture of pipeways in LMFBR type reactors. Constitution: The upper gas plenum in the reactor vessel of an LMFBR type reactor is connected to a negative pressure tank within a reactor container. By communicating the gas plenum and the negative pressure tank to each other upon rupture of the pipeways, the gas pressure in the upper gas plenum of the reactor vessel is reduced. Since this can moderate the coolant release from the reactor vessel and suppress the reduction in the coolant level within the reactor vessel, boiling in the reactor core can be prevented. (Moriyama, K.)