Patent Number: 039487245
Section: description

Referring to the drawing, and first particularly to FIG. 1, there is shown a nuclear reactor designated by the numeral 1 with a centrally disposed rotary cover 3 surrounded by a ring-shaped cover 2. The diameter of a rotary cover 3 is only slightly larger than the diameter of fission zone 4 situated beneath the cover. In the fission zone 4 are shown some fuel, breeder or absorber rods designated by the numeral 5. Receptacles or ducts 6 serve as transfer positions into which rods 5 may be moved from the fusion zone and thence outside of the reactor, or conversely rods may first be placed into receptacle 6 and then transfered into the fusion zone. Receptacle 6 also serves as a temporary storage place during rearrangement of rods 5 in fission zone 4. The annular space between the fission zone 4 and the reactor container 1 provides room for various instruments, accessories or fittings for monitoring and controlling the operation of the nuclear power plant, such as, for example inlets and outlets 7 and 8 for the liquid coolant, for the lock ducts 9 for the inlet and outlet of fuel elements 5, etc. Rotary cover 3 has a radially ending slot 10 through which a gripping device 12 may be lifted through the slot by means of the hoisting unit operated by an electric motor. In this manner the gripping device 12 may be lowered, opened and closed. Thus through radial movement of the hoisting unit 13 along slot 10 and through rotation of rotary cover 3, the gripping device 12 may be moved into position above any desired rod-shaped member 5. Gripping device 12 after grasping rod 5 may deposit the rod at any other location within the area swept by slot 10, such as, for example in disposal receptacle 6 into which the rod-shaped element may be placed and then transferred if desired, with a crane-like handling device 14, down to below locking duct 9. Receptacle 6 is preferably a movable container into which rod-shaped element is placed and then transported. As shown in greater detail in FIG. 3, the handling device comprises a hoisting unit 13 driven by an electric motor which permits raising and lowering the gripping device 12 via a lead spindle 15. Gripping devices are known and the mechanism for opening and closing the gripping device 12 was omitted in the drawing. Movement of the gripping device downwardly is facilitated by means of guide tube 16 through which it passes. The gripping device and the hoisting unit which moves it are merely illustrative since there are numerous constructions which may be used in the same manner. Shielding box 17 seated tightly upon reactor cover 3 and covering slot 10 encloses the hoisting unit. Hoisting unit 13 is fastened to carriage or cart 18 which glides in a guide 19 which, in this case, is provided in the wall of the shielding box 17, but which may also be situated in slot 10 proper. Between cart 18 which is moved by an electric motor drive 20, and the wall of the shielding box 17, a bellows 21 i.e. an expansion member such as a pleated member is provided on each side thereof for protecting the area of the shielding box 17 and thus the hoisting unit 13 against the corrosive effects of the reactor atmosphere. The bellows 21 may be sealed by means of loop seals. In order to make the handling device accessible to maintenance work, which necessitates removal of the shielding box 17, a separate shielding block 22 is provided which can be inserted sideways across the slot 10 and which seals the interior of the reactor container 1. In order to center guide tube 16 more precisely upon a specific fuel rod 5, and in order to control the position of the fuel rod in the fission zone 4, a scanning device may be provided which consists of another electric motor drive 24 which acts via rods 26 upon a rotatable scanning arm 25.