Patent Number: 051732505
Section: summary

FIELD OF THE INVENTION The present invention relates to an apparatus for demolishing a biological shield wall of a nuclear reactor after its life and a method of demolishing the same. PRIOR ART Conventionally, as a method of demolishing a biological shield wall of a nuclear reactor after its life, a method of mechanical cutting using a combined wall saw and a core boring machine, or a method of demolishing of fluid cutting dynamics using an abrasive water jet are proposed. This cutting method, however, applies a cutter device with its tripod legs fixed on the inside surface of a bell-shaped biological shield wall of a nuclear reactor, and its travelling operations with along the progressing of the operation are very troublesome, and the wall being a heavy structure, the fixing device therefor with the supporting legs assembled become comparatively larger, and by the fact that the device suffers radioactive contamination during the demolishing operation, there results a problem that mass of radioactive matters to be disposed of as the wastes increases after the operation. Then, in view of the above-mentioned current state, the present invention was made to eliminate the disadvantage of the prior art, and the object of which is to present a novel apparatus and a method of demolishing a biological shield wall of a nuclear rector without requiring a large scale for the apparatus even for the larger biological shield wall, and accordingly never resulting in the increasing of mass of active wastes, and with along the progressing of the cutting operation, easy movement and also improvement of the efficiency of the operation can be accomplished. DISCLOSURE OF THE INVENTION The feature of the present invention lies in that, in a demolishing apparatus for a biological shield wall of a nuclear reactor using a concrete cutter device working on a wire saw, said apparatus comprises a concrete cutter device consisting of a driving part for a wire saw and a concrete cutting part attached to the engaging receiver of the driving part, a core boring machine to be attached interchangeably on the engaging receiver in the place of the cutting part and a carrier truck to carry the wire saw driving part of said cutter device. Further, the concrete cutting part has a pair of vertical rods supported on a table movable vertically and adjustable in a distance from each other rods, and the table is pivoted to swing horizontally, and at the bottom end of the rods, supporting pulleys and guide rollers for arranging the wire saw are provided. The other feature of the present invention lies in that, in a method of demolishing a biological shield wall of a nuclear reactor using the demolishing apparatus described above, a method comprising a step of setting the carrier truck on the operating floor of the reactor building, with a core boring machine attached on the reciever and with the carrier moving on, a step of boring holes downward from top of the shield wall at a predetermined distance, then with the concrete cutting part attached in the place of the boring machine, a step of inserting a pair of vertical rods in the bored hole through adjusting of the table to circurate the wire saw between the supporting pulleys, while with the carrier moved along and the vertical rods controlled and adjusted to enable the cutting of wire saw to cut a concrete block from the shield wall to dispose finally. According to the present invention, by setting the carrier truck carrying the wire saw driving part attached by the wire saw cutting part on the operating floor of the reactor building, the biological shield wall is cut and demolished by the core boring machine and the wire saw cutting part, and then, with along the progressing of the cutting operation, easy movement and also improvement of the efficiency of the operation can be accomplished, without requiring a large scale for the apparatus even when the biological shield wall gets larger, and accordingly never resulting in the increasing of mass of active wastes. The other features of the present invention are understood by the following non-limiting embodiments shown in the following drawings.