Method for performing remotely-manipulated work on a conduit of a nuclear facility

A method for maintaining the pipe conduits of a radioactively charged cell of a reprocessing facility for irradiated nuclear fuel wherein a portion of a conduit can develop a leak or become otherwise defective, the method comprising the steps of:

• cutting the defective portion from the conduit thereby forming two mutually adjacent cut conduit end faces corresponding to respective conduit end portions;
• tightly clamping said end portions to align the same with respect to each other;
• moving a machining unit to the end face of one of the conduit end portions and machine planing said one end face;
• selecting the planed end face as a first reference point for measuring the length of the clear dimension between said conduit end portions;
• displacing the machining unit to the end face of the other one of said conduit end portions and machine planing said end face of said other conduit end portion;
• selecting the planed end face of said other conduit end portion as the end reference point for measuring said clear dimension;
• measuring the displacement of the machining unit from said first reference point to said end reference point;
• determining the length of said clear dimension and therefore of a replacement conduit segment with the aid of the measured value of said displacement;
• preparing said replacement conduit segment having said length;
• remotely manipulating said conduit segment into the gap between said conduit end portions;
• and,
• welding said conduit segment to said conduit end portions.