Steam driven water injection

Claim 1

In a nuclear system including a pressure vessel containing a nuclear reactor core for generating steam, an injection system for supplying water through a return pipe of the pressure vessel, said injection system comprising first and second steam-driven water injectors for driving water, each of them including an inlet and an output for water and effective for raising water pressure between inlet and output; first pipe means for applying steam from said vessel to said first injector; second pipe means for connecting the output of said first injector to the inlet of the second injector, the output of said second injector being effective for feeding water into said return pipe of the pressure vessel; first cooling means for cooling water passing through said second pipe means, said first cooling means being in thermal communication with said second pipe means; jet pump means for receiving input water from a source of water and effective for directing it to the inlet of said first injector, said second pipe means including a branch effective for diverting a portion of the water flowing from the output of said first injector to said jet pump means wherein said portion of water is effective for entraining water from said source of water for introduction into the inlet of said first injector; and second cooling means for cooling said portion of water in the branch of said second pipe means and subject to thermal communication with said branch, whereby the operational capability of said injection system for raising the pressure level of water in said return pipe is increased.