Reactor primary coolant ducts in second containment - with pressurised annular space to relieve primary ducts of stress

摘要

A method operating press. ducts which are surrounded by an outer, press-resistant pipe system, esp. for operating the water coolant ducts of a nuclear power plant, consists of filling the annular space between inner duct and outer pipe with a fluid medium (typically air) which is at the same press. as the fluid in the inner duct. The annular space pref. contains a porous, solid substance, through which the fluid medium flows. Where the double pipe-and-duct system provides a second containment for a reactor prim. circuit, the introduction of pressurised fluid into the annulus relieves the inner duct of press. and thus obviates risk of a burst. The provision of porous, solid material in the annulus ensures insulation of the inner duct without obscuring the outer pipe from visual inspection.