Patent Number: 047956062
Section: summary

BACKGROUND OF THE INVENTION This invention relates to inspection systems, particularly for nuclear reactor installations. FEATURES AND ASPECTS OF THE INVENTION According to this invention, there is provided apparatus for inspecting the surface of a structure comprising a track extending around an upper region of the structure, an elongated flexible carrier engageable along its length with the track and movable lengthwise along the track, means for leading the flexible carrier insertably into engagement with the track, and retractably out of engagement with the track, at at least one position along the length of the track, and inspection means carried by the carrier for selective downward extension and upward retraction relative to the carrier and relative to the track. The structure may for example be a tube or vessel. The vessel may be closed or open topped. Also in accordance with the invention, the aforesaid apparatus is provided in combination as part of a nuclear reactor installation including a primary vessel surrounded externally by a guard vessel and defining an annular space therebetween, the track extending around the top of the primary and guard vessels, and the inspection means being extendable into and retractable from the annular space. The flexible carrier may comprise a series of tubular members, adjacent members being connected for relative movement. The adjacent members may for example be connected by flexible bellows. The inspection means may comprise a camera carried at an end of a cable extending through the flexible device. The track may comprise spaced elements defining a slot, said flexible carrier having guide means engaging the spaced elements. The guide means may comprise rotatable means. The inspection means may extend between the spaced elements when being moved up and down.