Patent ID: 8048319

Claim:
A method for filtering water contained in a containment sump of an emergency core cooling system of a nuclear reactor comprising the steps of: inserting a woven or knitted, stainless steel filter medium into an interior annular space of at least one filter module, said interior annular space being between two concentric cylindrical strainer walls that are connected to a plenum box, wherein said filter module includes a circular plate attached to the innermost cylindrical strainer wall at the end closest to said plenum box, thus blocking bypassing liquid flow between the interior of said module within the inner cylindrical strainer wall and a cavity of the plenum box; retaining said filter medium within said interior annular space; pumping water from said containment sump sequentially through said strainer walls, said filter medium, a ring shaped opening in fluid communication with said interior annular space and said plenum cavity, and then through said plenum to produce filtered water that is substantially free of debris that would detrimentally affect downstream components; and pumping said filtered water to a reactor core.