Abstract: A nuclear reactor containment cooling system includes a containment vessel having a drywell and a wetwell, a cooling condenser submerged in a cooling pool of water located outside the containment vessel, a vent line extending from the condenser to a suppression pool disposed in the wetwell, and at least one drain line extending from the condenser to a condensate drain tank located in the drywell. An end of the drain line is vertically submerged below the surface of a pool of water in the drain tank. To enhance flow, a blower can be located in the drain line. The containment cooling system can include a drywell gas recirculation subsystem coupled to the vent line, and including a suction pipe coupled to the vent line, at least one valve located in the suction pipe, at least one blower coupled to the suction line, and a discharge pipe in flow communication with the drywell.

Abstract: A nuclear reactor containment cooling system includes a containment vessel having a drywell and a wetwell, a cooling condenser submerged in a cooling pool of water located outside the containment vessel, a vent line extending from the condenser to a suppression pool disposed in the wetwell, and at least one drain line extending from the condenser to a condensate drain tank located in the drywell. An end of the drain line is vertically submerged below the surface of a pool of water in the drain tank. To enhance flow, a blower can be located in the drain line. The containment cooling system can include a drywell gas recirculation subsystem coupled to the vent line, and including a suction pipe coupled to the vent line, at least one valve located in the suction pipe, at least one blower coupled to the suction line, and a discharge pipe in flow communication with the drywell.

Abstract: Modified passive containment cooling systems for cooling a reactor core of a boiling water nuclear reactor are described. The passive containment cooling system (PCCS), in one form, includes a vent line coupled to the vacuum breaker. The vent line includes a first end, a second end, and a passage extending between the first and second ends for transporting noncondensibles between the first and second ends. The first end is coupled to PCCS condenser, and the second end is submerged in a suppression pool. A branch extends from an intermediate portion of the vent line and is coupled to the vacuum breaker. The branch includes a first end, a second end, and a passage extending between the first and second ends. The first end of the branch is coupled to the intermediate portion of the vent line so that the branch passage is in communication with the vent line passage.