Integrated head assembly for a nuclear reactor

Abstract

An integrated head assembly ( 100 ) is disclosed for a nuclear reactor. The preferred integrated head assembly includes a lift assembly ( 150 ) that supports the reactor vessel closure head ( 90 ) and integrated head assembly for removal, a separate support structure ( 202 ) supported by a ring beam ( 151 ) that sets atop the reactor vessel closure head, a shroud assembly ( 200 ), a seismic support system ( 300 ), a baffle assembly ( 500 ), a missile shield ( 400 ), and a CRDM cooling system. The CRDM cooling system draws cooling air into the baffle assembly, downwardly past the CRDMs ( 96 ), outwardly to upright air ducts ( 600 ), upwardly to an upper plenum ( 680 ), and out of the assembly through the air fans ( 190 ). In a second embodiment the integrated head assembly ( 1100 ) includes a missile shield ( 1400 ) and CRDM cooling system ( 1600 ) that permits access to individual CRDMs from above.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . An integrated head assembly for a nuclear reactor having a reactor vessel closure head with a plurality of lifting lugs wherein the reactor vessel closure head supports a plurality of control rod drive mechanisms, the integrated head assembly comprising: 
 a plurality of lift rods that extend upwardly from the reactor vessel closure head, each lift rod adapted to engage one of the lifting lugs;    a lower ring beam supported by the reactor vessel closure head;    a shroud assembly supported by the lower ring beam, the shroud assembly comprising a support structure and a plurality of ducts, each duct having an inlet disposed near the reactor vessel closure head and an outlet disposed distally from the inlet;    a seismic support assembly that engages the control rod drive mechanisms and is attached to the shroud assembly;    a missile shield assembly attached to the shroud assembly and disposed above the control rod drive mechanisms; and    a plurality of fans, wherein each fan is fluidly connected to the outlet of at least one of the plurality of ducts.