Low head loss modular suction strainer with contoured surfaces

Abstract

A strainer for an emergency core cooling system (ECCS) in a nuclear power plant comprises a perforated strainer element that is immersed in a reservoir of cooling water, which is drawn through the strainer element into the emergency core cooling system. The side of the strainer element in contact with the cooling water has a contoured configuration for disrupting the formation of a flat bed of fibrous material that can trap small particulate material intended to pass through the strainer element. Incorporating this strainer element into an ECCS strainer enables the strainer to be made more compact, because the debris bed need not be spread over an unduly large area to prevent excessive head loss from the debris load in the event of a reactor loss of coolant accident. The strainer also incorporates a modular construction that uses individual strainer disc modules. Each disc module includes a perforated first disc part having a central opening and a perforated second disc part also having a central opening. The first and second disc parts fit together to form an interior space with facing perforated major surfaces and an axial opening, and connecting tubes between the discs place the axial openings in fluid communication. The entire assembly is secured together by tie rods that hold the discs together with the connecting tubes compressed between them.