An effluent container has two halves which fit together to form a cylinder, open at the top, for catching residual contaminated water falling from the control rod drive (CRD) housing under the influence of gravity when the seal between the CRD housing and the CRD is broken. The container has an aperture which fits around the extension rod that supports the CRD when the mounting bolts are removed. The container halves are held together by elastic cords stretched between hooks on the side-walls. The effluent container has L-shaped slots which hook onto the bracing bolts of the sway brace system to support the container in position for catching falling water. Spilled water drains out of the container to a sump.