Self-expanding waterproof cover for crane hook

A nuclear reactor system comprising:

• a reactor pressure vessel disposed in a reactor cavity, said reactor cavity including a separator pool which is separated from said reactor pressure vessel by a separator pool threshold;
• an overhead crane disposed above said reactor cavity and arranged to lift and transport a device which is normally disposed in said reactor pressure vessel, from said reactor pressure vessel to said separator pool while said reactor cavity is filled to a predetermined depth with water, said overhead crane including:
• a hook block which is suspended from said crane by cables;
• a hook operatively connected with said hook block and engageable with said device;
• a hook box which encloses said hook;
• a tubular extension which extends upwardly from said hook bock and which encloses said hook block and a portion of said cables;
• and
• a bellows arrangement provided at the upper end of said tubular extension, said bellows arrangement including:
• a flexible corrugated tube section, said flexible corrugated tube section having a lower end which is connected to said tubular extension in a manner which provides a watertight connection;
• and
• a buoyant member which is connected to an upper end of said corrugated tube section and effective to float on the surface of the water and cause said flexible corrugated tube to extend when said hook box is lowered to a predetermined depth below a surface of the water.

A method of preventing radioactive contamination of a hook, a hook block and associated cables, by:

• enclosing the hook and hook block in a hook box on which a tubular extension has been provided;
• providing a bellows arrangement at the top of the tubular extension;
• and
• using a buoyant member which forms part of the bellows arrangement and which floats on the surface of water used to suppress radioactive emissions, to elongate a flexible tubular portion which forms part of the bellows arrangement when the hook box submerges by a predetermined amount below the surface of the water.

An enclosure for a device comprising:

• a container-like structure which encloses said device;
• a flexible corrugated tube member which is sealingly connected to said container-like structure;
• and
• floatation means for causing said flexible corrugated tube member to extend upwardly when said container-like structure is immersed in water and prevent water from entering said container-like structure and coming into contact with said device.