Jet pump in a boiling water-type nuclear reactor

Claim 1

In a heat-generating reactor apparatus comprising a nuclear chain reacting core having an inlet and an outlet through which cooling water flows to be heated, said water having an inlet temperature of from about 400* to about 650* F.; and a pump for circulating the cooling water through said core at a ratio of driven water to driving water of from about 1 to about 2.5; the improvement comprising circulating said water with a jet pump having a mixer section with a ratio of length to diameter of from about 10.5 to about 13.5; said jet pump including a nozzle directing a driving fluid into said mixing section through an inlet section, said nozzle having a converging generally conical configuration with an opening having a diameter of about 0.30 to about 0.53 multiplied by the diameter of said mixing section; said opening located substantially on the centerline of said mixing section at a distance of up to twice the mixing section diameter from the beginning of said mixing section; the angle included by the exterior walls of said of the converging section of said nozzle being from about 14* to about 50* and the angle included by the interior walls of said converging section being from about 4* to about 30*; the interior wall of said nozzle having a right circular cylindrical internal surface having a length of about 0.1 to about 0.3 multiplied by the diameter of said nozzle opening; and an edge at the nozzle opening with a surface substantially perpendicular to the nozzle axis, the edge having a thickness of from about 0.01 to about 0.20 inch.