Patent Number: 042077230
Section: summary

The present invention relates generally to nuclear reactors, and more particularly to a novel system facilitating transfer, canning and inspection of fuel and reflector elements between a nuclear reactor vessel and a storage area while maintaining the elements in a gaseous environment sealed against egress of radioactive contaminants and ingress of air. Nuclear reactors conventionally employ an active core which includes an array of fuel elements generally surrounded by reflector elements. It is a necessary incident to the operation of a nuclear reactor system to periodically remove radioactive elements, such as fuel and reflector elements, from the nuclear reactor and to transport such radioactive elements to a location remote from the nuclear reactor core for canning, inspection and storage. During handling of such fuel and reflector elements, it is important that personnel are adequately shielded from the radioactive elements themselves and from equipment which may be exposed to, and thereby contaminated by, the elements. It is equally important that the elements be maintained in a gaseous environment during transit, sealed against egress of radioactive contaminants and ingress of air. One of the primary objects of the present invention is to provide a remotely controllable system which facilitates transfer of fuel and reflector elements between a reactor vessel core and a storage area while maintaining the elements in a gaseous environment sealed against egress of radioactive contaminants and ingress of air. A more particular object of the present invention is to provide a novel system for canning and inspecting fuel and reflector elements of a nuclear reactor remote from the reactor vessel, while maintaining the elements in a desired gaseous environment. Another object of the present invention is to provide a novel system for transferring, canning and inspecting fuel and reflector elements of a nuclear reactor, which system employs a transfer chute, environmental chamber, conveyor and canning mechanism operative to remove and replace the closures of containers in which the fuel and reflector elements are sealed, while maintaining a gaseous environment in the containers and permitting visual and mechanical inspection of the elements by operators located in a remote, shielded area. A feature of the system in accordance with the present invention lies in the provision of an environmental chamber at the lower end of the transfer chute and in which a grapple is provided for removing the closure lids of containers disposed within chambers of an underlying conveyor, the grapple being operative to move the closure lids to a storage area and subsequently move the same or a new lid into a position for reattachment to the container. A further feature of the system in accordance with the present invention lies in the provision of a seal forming arrangement wherein a sealed relation is effected between an opening in the lower end of the environmental chamber and an associated underlying conveyor chamber so that a predetermined gaseous environment may be maintained about an element being placed into or withdrawn from a container disposed within the conveyor chamber.