Strainers for emergency core cooling systems—ECCS

A filtration apparatus for an Emergency Core Cooling System of a nuclear power plant, the filtration apparatus comprising:

• a substantially rectangular body bounded by four non-welded closed surfaces that define an open volume, wherein the body includes
• at least one outlet extending through at least one of the four closed surfaces, and
• fixed plates mounted on interior surfaces of the rectangular body;
• punched plate filter screens mounted within the open volume of the body, wherein
• the punched plate filter screens engage the fixed plates and define a discharge space within the open volume, and
• the discharge space is bounded by the closed surfaces and the punched plate filter screens, and is in fluid communication with the outlet;
• and
• a modular cassette including
• a first set of dual wall filtration plates having a first set of uniformly spaced grooves, and
• a second set of dual wall filtration plates having a second set of uniformly spaced grooves, wherein
• the first and second sets of uniformly spaced grooves orthogonally engage each other, without welding,
• the first and second sets of dual wall filtration plates define a grid of hollow filtration elements and a continuous hollow interior volume within the grid of hollow filtration elements,
• a first of the hollow filtration elements engages a first of the punched plate filter screens on a first side of the discharge space,
• a second of the hollow filtration elements, which is substantially identical to the first of the hollow filtration elements, engages a second of the filter screens on a second side, opposite the first side, of the discharge space, so that
• cooling water to be filtered flows into the open volume from two opposed sides of the discharge space,
• a first portion of the cooling water flows through the first and second hollow filtration elements and then flows through the punched plate filter screens and into the discharge space,
• a second portion of the cooling water flows only through the punched plate filter screens into the discharge space, and
• the cooling water that has entered the discharge space flows out through the outlet.