Two-piece replaceable gastight utility plugs for the walls of hot cells

Gastight utility plugs for the shielding walls of hot cells are mainly used for the passage of mechanical actuating mechanisms, for electric cables, for the passage of liquid and gaseous media and for purposes of visual inspection. The plugs are normally inserted in steel or brass casings. The design requirements for such plugs are: (a) safe prevention of the contamination of the operating room located in front of the Hot Cell: (b) mutual replaceability of plugs (for example, a mechanical plug must be capable of replacement by an electric plug); (c) the radiation shield of the utility plugs must be equivalent to an 85 cm or 110 cm thick baryte concrete wall having a density of 3.5 t/m3; (d) excellent gastight properties are required in order to ensure that the vacuum underpressure of 10-15 mm H20 inside the Hot Cell cannot entrain air from the outside. A design solution which meets these requirements for a mechanical utility plug is described. (author)