Patent Number: 
Section: abstract

A pressurized water nuclear reactor (PWR) has an internal pressurizer volume containing a steam bubble and is surrounded by a containment structure. A condenser is disposed inside the containment structure and is operatively connected with an external heat sink disposed outside of the containment structure. A valve assembly operatively connects the PWR with the condenser responsive to an abnormal operation signal such that the condenser condenses steam from the steam bubble while rejecting heat to the external heat sink and returns the condensed water to the PWR. A quench tank contains water with dissolved neutron poison. A valved tank pressurizing path selectively connects the steam bubble to the quench tank to pressurize the quench tank, and a valved soluble poison delivery path selectively connects the quench tank to the PWR such that the quench tank under pressure from the steam bubble discharges water with dissolved neutron poison into the PWR.