Boiling water reactor with compact containment and simplified safety

Abstract

A nuclear reactor having a pressure vessel which is open at the top. The open top of the pressure vessel is closed by a steel dome. A containment, which is open at the top, extends upward from and is joined to the top of the pressure vessel and has an open containment head at the top thereof. The open top of the containment is closed by a steel dome, thereby forming a containment well bounded laterally by the containment, on the bottom by the vessel closure and on the top by the containment closure. The pressure vessel can be a steel-lined prestressed concrete vessel, while the containment is formed by an extension of the prestressed concrete vessel. Alternatively, the pressure vessel and the containment are parts of a unitary steel vessel. Isolation valves are installed on each penetration pipeline to isolate the system in the event of a loss-of-coolant accident. An isolation valve located external to the pressure vessel and the portion of the pipeline between that external isolation valve and the interior of the pressure vessel are encased in guard piping. The space between the pipeline and the guard piping is pressurized and monitored to detect any leak in either the pipeline or the guard piping.