This International Standard provides strategies, technical requirements, and recommended practices for the management of normal ageing of cabling systems that are important to safety in nuclear power plants. The main requirements are presented in the body of this International Standard followed by a number of informative annexes with examples of cable testing techniques, procedures, and equipment that are available for the nuclear industry to use to ensure that ageing degradation will not impact plant safety. This International Standard covers cables and their accessories (e.g., connectors) installed in nuclear power plants (inside and outside the containment). It provides requirements to perform cable testing for the purposes of predictive maintenance, troubleshooting, ageing management, and assurance of plant safety. It is concerned with Instrumentation and Control (I&C) cables, signal cables, and power cables of voltages less than 1 kV. More specifically, this International Standard focuses on in-situ testing techniques that have been established for determining problems in cable conductors (i.e., copper wire) and, to a lesser extent, on insulation material (i.e., polymer). It follows the IEC 62342 standard on “Management of Ageing” that was prepared to provide general guidelines for management of ageing of I&C components in nuclear power plants, including cables. It should be pointed out that cable testing technologies are evolving and new methods are becoming available that are not covered in this International Standard. More specifically, this International Standard covers typical cable testing methods that have been in use in the nuclear power industry over the last decade. It should also be pointed out that a single cable testing technique is unlikely to provide conclusive results, and a reliable diagnosis normally requires a combination of techniques.