Patent Number: 046648739
Section: summary

FIELD OF THE INVENTION The invention relates to remotely-controlled manipulator carrier systems for use in large-area cells affected by radioactivity wherein industrial processes are conducted. The cells are part of a nuclear facility for reprocessing irradiated nuclear fuel materials. The cell is defined by an enclosure and a remotely-controlled bridge crane is arranged beneath the ceiling of the enclosure. The bridge crane includes a vertical, rotatable guide column mounted on a supporting member arranged above the process components in the cell. A support is movably mounted on the guide column for vertical movement and an extendible arm is arranged on this support. The extendible arm is adapted to receive a manipulator or other remotely-controlled device to perform manual-like maintenance operations on the process components and equipment arranged in the large-area cell. BACKGROUND OF THE INVENTION Facilities for the reprocessing of irradiated nuclear fuel materials are equipped with so-called hot cells for holding the components needed for conducting the industrial processes associated therewith. In these radiation-shielded cells, the process components are arranged in scaffold-like structures or racks as they are sometimes referred to. The maintenance work within the hot cell affected by radioactive radiation should be conducted preferably without the necessity of operating personnel entering the hot cell. Solutions have been therefore sought to conduct the maintenance work by means of remotely-controlled equipment which can be movable within the hot cell. For this purpose, it is desirable that the racks holding the components used in the industrial processes be arranged in mutually adjacent rows longitudinally along the walls of the hot cell. In this way, a center passageway is formed along which the remotely-controlled equipment for the maintenance work can be moved and for exchanging the individual process components or exchanging fully-loaded racks. For the maintenance work and the exchange of individual process components or of entire racks, a combination of remotely-controlled machines for performing manual-like operations are utilized. The overhead bridge crane passes over both rows of racks and the center passageway. After all connections and conduits are disconnected, the racks or heavy individual components are lifted from their anchor locations with the aid of the overhead bridge crane. The bridge crane then moves the racks or individual components horizontally into the transport passageway. The control room for the remotely-controlled bridge crane is located outside of the hot cell. In addition to the overhead bridge crane, a manipulator carrier apparatus is provided which can act in the horizontal direction from the central transport passageway to engage the process components and to position operating devices, maintenance device and tools. This manipulator carrier apparatus opens up the possibility for utilizing electrical servo and power manipulators as well as providing the capability for the future use of robots and programmed apparatus. Manual-like operations are performed on small components with the available manipulators and lifting devices in dependence upon the configuration of the carrier apparatus. The manipulator carrier apparatus includes a vertical guide column arranged on a second overhead bridge crane movable below the first overhead bridge crane in the direction of the longitudinal axis of the hot cell; or, if desired, the column can be mounted on a half bridge movable below the overhead bridge crane. The rotatable guide column includes an extendable arm mounted on a support which can be moved vertically up and down. The extendable arm is adapted to receive the tools or equipment for performing manual-like operations. A division of work is achieved with the arrangement of the first overhead bridge crane and the manipulator carrier apparatus. The remotely-controlled first overhead bridge crane is used primarily for holding and transporting pipe connections, components and individual racks. If necessary, the first overhead bridge crane can take over the lowering and holding of tools as well as separating and welding equipment. The manipulator carrier apparatus which is movable along the central passageway serves to guide and hold impact wrenches or other special tools which are needed to effect disassembly work. Further, the manipulator carrier apparatus and second overhead bridge crane can be adapted for accommodating video equipment or other helpful ancilliary devices. SUMMARY OF THE INVENTION It is an object of the invention to provide an arrangement to improve the utilization of the remotely-controlled equipment so that both the first overhead bridge crane and the manipulator carrier apparatus can be brought to work at the same location simultaneously. The system of the invention performs remotely-controlled, manual-like operations in a large-area hot cell of a facility for reprocessing irradiated fuel materials. The hot cell is an enclosure with process equipment disposed along at least one longitudinally extending wall thereof whereby a canyon-like passageway is defined which extends in the direction of the longitudinal axis of the enclosure. The system of the invention includes a first overhead bridge crane having a trolley movable thereon in a direction transverse to said longitudinal axis. The trolley includes hoist means for lowering and raising a device for engaging and moving a component of the process equipment in a first vertical plane transverse to the axis. A second overhead bridge crane is disposed beneath the first overhead bridge crane. Elevated track means guides the first and second bridge cranes in the enclosure in respective horizontal planes and in the direction of the longitudinal axis. The second overhead bridge crane includes an elongated supporting member arranged transversely to the longitudinal axis of the enclosure above the passageway and engages the track means for movement therealong. A manipulator assembly has a mast that extends downwardly into the canyon-like passageway from the supporting member. The supporting member and the mast conjointly define a second vertical plane transverse to the longitudinal axis of the enclosure. The manipulator assembly further includes manipulator means for performing manual-like operations on the process equipment and is mounted asymmetrically on the mast so as to be on one side thereof and in a third vertical plane transverse to the longitudinal axis of the enclosure. Means are provided for moving the first overhead bridge crane along the track means to bring the first vertical plane into coincidence with the third vertical plane so as to permit movement of the engaging device in the third vertical plane clear of the elongated supporting member whereby both the manipulator means and the engaging device can be brought simultaneously to a predetermined work location at the processing equipment. During maintenance work involving both the first overhead bridge crane for lifting and holding a component of the process equipment and the manipulator carrier apparatus made up of the above-mentioned manipulator assembly and second overhead bridge crane, the execution of manual-like movements by the manipulator assembly and the lifting movement of a component of the process equipment by the first overhead bridge crane at the same work location do not interfere with each other. The guide column or mast and the hoist cable of the first overhead bridge crane are displaced with respect to each other and are in two different vertical planes of the hot cell.