Abstract: A device which is a natural circulation cooling water system, comprising coolers made up of several rows of vertical tubes for cooling water, a header supplying cooling water to said tubes from a separating tank, being referred hereinafter to as a separator, and a header discharging steam-water mixture from the coolers to the separator.Both the inlets and outlets of the rows of the cooler tubes are in addition individually connected through cutoff means to a service water supply pipe and to a drain pipeline accordingly. The cutoff means are designed so that when they are placed in one position the tubes are connected to the cooling water natural circulation system while in another position they are coupled to a service water cooling system.

Abstract: An apparatus comprising one or more closed systems for the natural circulation of cooling water, comprising a cooling-water manifold, a pipeline for feeding water from the manifold to one or more coolers or cooler sections in the system, and steam-water pipelines for discharging the mixture from the coolers. Each cooler or section may be provided with an individual steam separator communicating with its steam outlet to an associated discharge pipeline, and connected with its water side to the steam side of the manifold.