Compact nuclear reactor with integral steam generator

摘要

In an illustrative embodiment, a pressurized water nuclear reactor (PWR) includes a pressure vessel (12, 14, 16), a nuclear reactor core (10) disposed in the pressure vessel, and a vertically oriented hollow central riser (36) disposed above the nuclear reactor core inside the pressure vessel. A once-through steam generator (OTSG) (30) disposed in the pressure vessel includes vertical tubes (32) arranged in an annular volume defined by the central riser and the pressure vessel. The OTSG further includes a fluid flow volume surrounding the vertical tubes and having a feedwater inlet (50) and a steam outlet (52). The PWR has an operating state in which feedwater injected into the fluid flow volume at the feedwater inlet is converted to steam by heat emanating from primary coolant flowing inside the tubes of the OTSG, and the steam is discharged from the fluid flow volume at the steam outlet.

主权项

1. An apparatus comprising:
a generally cylindrical pressure vessel defining a cylinder axis; a nuclear reactor core disposed in the generally cylindrical pressure vessel; a central riser disposed coaxially inside the generally cylindrical pressure vessel, the central riser being hollow and having a bottom end proximate to the nuclear reactor core to receive primary coolant heated by the nuclear reactor core, the central riser having a top end distal from the nuclear reactor core; a feedwater inlet comprising a vessel penetration of the generally cylindrical pressure vessel; a steam outlet comprising a vessel penetration of the generally cylindrical pressure vessel; and a once-through steam generator (OTSG) comprising tubes arranged parallel with the cylinder axis in an annular volume defined between the central riser and the generally cylindrical pressure vessel, primary coolant discharged from the top end of the central riser flowing inside the tubes toward the nuclear reactor core, the OTSG further including a fluid flow volume in fluid communication with the feedwater inlet and with the steam outlet wherein fluid injected into the fluid flow volume at the feedwater inlet and discharged from the fluid flow volume at the steam outlet flows outside the tubes in a direction generally opposite flow of primary coolant inside the tubes; wherein a feedwater annular space is defined between an outer shroud of the OTSG and the pressure vessel, the fluid flow volume at being in fluid communication with the feedwater inlet via the feedwater annular space; and wherein a steam annular space is defined between the outer shroud of the OTSG and the pressure vessel, the fluid flow volume at being in fluid communication with the steam outlet via the steam annular space; wherein the feedwater annular space has a larger outer diameter than the steam annular space.