Patent ID: 7120219

Claim:
In a pressurized water nuclear reactor, a reactor pressure vessel for containing fuel assemblies in coolant water, comprising: a removable top head having a flange with a bottom surface; a vessel body having an internal support ledge; a core barrel assembly having a flange supported on the internal support ledge for supporting the filet assemblies, the core barrel assembly flange having holes extending between a lower flange surface and an upper flange surface, each hole having a cross-sectional area; and an upper support plate having a flange with a lower flange surface and an upper flange surface, the lower surface of the upper support plate flange disposed above the upper surface of the core barrel assembly flange, the upper support plate flange having holes extending between its lower surface and its upper surface and aligned with the holes in the bore barrel assembly, the upper support plate having exhaust nozzles extending from the holes and above its upper surface, each exhaust nozzle having an exit port having an exit flow area that is larger than the cross-sectional area of the aligned hole in the core barrel assembly, and each exit port is disposed above the bottom surface of the top head flange.