Pressurized water reactor with upper vessel section providing both pressure and flow control

摘要

A pressurized water reactor (PWR) includes a vertical cylindrical pressure vessel having a lower portion containing a nuclear reactor core and a vessel head defining an internal pressurizer. A reactor coolant pump (RCP) mounted on the vessel head includes an impeller inside the pressure vessel, a pump motor outside the pressure vessel, and a vertical drive shaft connecting the motor and impeller. The drive shaft does not pass through the internal pressurizer. A central riser may be disposed concentrically inside the pressure vessel, and the RCP impels primary coolant downward into a downcomer annulus between the central ser and the pressure vessel. A steam generator may be disposed in the downcomer annulus and spaced apart from with the impeller by an outlet plenum, A manway may access the outlet plenum so tube plugging can be performed on the steam generator via access through the manway without removing the RCP.

主权项

1. An apparatus comprising:
a pressurized water reactor (PWR) including: a cylindrical pressure vessel with its cylinder axis oriented vertically, a nuclear reactor core disposed in the cylindrical pressure vessel, a separator plate disposed in the cylindrical pressure vessel that separates the pressure vessel to define an internal pressurizer containing a pressurizer volume disposed above the separator plate and a reactor vessel portion defining a reactor volume disposed below the separator plate and containing the nuclear reactor core, wherein the separator plate restricts but does not completely cut off fluid communication between the pressurizer volume and the reactor volume, wherein the cross-section of the cylindrical pressure vessel includes a narrowed portion defining a recess of the internal pressurizer wherein the pump motor is disposed at least partially in the recess; and a reactor coolant pump including (i) an impeller disposed inside the pressure vessel in the reactor volume, (ii) a pump motor disposed outside of the pressure vessel, and (iii) a drive shaft operatively connecting the pump motor with the impeller, wherein (1) at least a portion of the pump motor is disposed above the separator plate (2) no portion of the reactor coolant pump is disposed in the pressurizer volume and (3) the drive shaft of the reactor coolant pump is oriented parallel with the cylinder axis of the cylindrical pressure vessel.