Abstract: The invention relates to an apparatus for demolishing a reactor shield wall. The apparatus has a pillar (2) extending from the top side of the reactor toward the bottom of the reactor, an upper support device (3) for supporting the upper portion of the pillar (2) at the top side of the reactor, and cutting devices (5, 6) mounted to the pillar so as to be upwardly and downwardly movable along the pillar (2). The pillar (2) is rotatably supported by the support device (3). The upper support device (3) has drive devices (30, 31, 32) for rotating the pillar (2). The cutting devices (5, 6) are caused to swing in the reactor interior by rotating the pillar (2). The drive devices are disposed at the top side of the reactor, and this permits easy maintenance and inspection.

Abstract: A clean room having an air-conditioner unit built in the shell of an airtight main room in such a manner as to form part of the internal wall of the main room. This air-conditioner unit is provided with an external casing of a small thickness and this external casing is provided with an air inlet and an air outlet which is fitted with a high-performance filter. The casing has an air blower disposed therein. The airtight main room is mainly formed of a plurality of gate-shaped frames disposed in parallel as regularly spaced on a floor surface. The air-conditioner unit and a control unit are disposed in the spaces intervening between the adjacent vertical members of the gate-shaped frames. The internal wall of the main room is formed of wall panels and the front panel of the casing of the air-conditioner unit.