Patent ID: 7873136
Filing Date: 2011-01-18
Classification: G21C,Y02E

Abstract:
1. An injection system for a neutron poison for an emergency shutdown of a nuclear reactor, the injection system comprising: an absorber liquid having an absorption cross section that captures free neutrons; a pressure vessel containing a propelling fluid being essentially water; an overflow line communicating with a core region of a reactor pressure vessel of a nuclear reactor, the core region being external to said pressure vessel; a reservoir vessel storing said absorber liquid at room temperature, said reservoir vessel connected, via said overflow line, to said pressure vessel; and an outflow line connected to said bottom region of said reservoir vessel; and a shut-off apparatus having a closed position that closes said outflow line and an open position that opens said outflow line thereby causing the absorber liquid to be pushed through said outflow line by the propelling fluid; said reservoir vessel being spatially separated from said pressure vessel, and only said overflow line connecting said reservoir vessel to said pressure vessel such that pressure is equalized between said reservoir vessel and said pressure vessel; said pressure vessel formed with a ceiling region and a bottom region, said pressure vessel including a heating device configured to heat and partially evaporate the propelling fluid in order to form a vapor cushion located in said ceiling region of said pressure vessel, wherein an un-evaporated portion of the propelling fluid defines a liquid portion located below the vapor cushion; said overflow line connecting said bottom region of said pressure vessel to said ceiling region of said reservoir vessel, said overflow line including a riser; and said overflow line including a plurality of nozzles discharging the propelling fluid near said ceiling region of said reservoir vessel.