control device for pressure vessel of nuclear reactors in service

摘要

Method and apparatus for in-service inspection of nuclear reactor vessel welds. A support mechanism housing an inspection device is positioned within the reactor vessel after the internals thereof are removed. The hoist mechanism for the refueling device is then used to manipulate the inspection device from its support mechanism to the weld areas to be inspected. The inspection device includes means for remote visual and volumetric examination of the cladding and weld surfaces, respectively, as well as a displacement indicating means for determining the position of the inspection device with respect to the weld being inspected.