What is ISO 20890 ‑ 4 about?
ISO 12749-4 is the fourth part of the multi-series European standard that specifies guidelines for pre-service inspection (PSI) and in-service inspections (ISI) for reactor coolant circuit components of light water reactors and their installations as direct or remote visual testing in the form of a general visual testing (overview), or selective visual testing (specific properties).
ISO 20890 ‑ 4 focuses on the requirement of remote (mechanized) visual testing but also specify global requirements for direct visual testing.
Note: Data concerning the test section, test extent, inspection period, inspection interval and evaluation of indications is defined in the applicable national nuclear safety standards.
Note: ISO 20890 ‑ 4 is not applicable to tests in respect to the general state that are carried out in conjunction with pressure and leak tests and regular plant inspections.