ISO DIS 20890-1

Description / Abstract: This document gives guidelines for pre-service-inspections (PSI) and in-service inspections (ISI) with mechanized ultrasonic test (UT) devices on components of the reactor coolant circuit of light water reactors. This document is also applicable on other components of nuclear installations.

Mechanized ultrasonic inspections are carried out in order to enable an evaluation in case of

— malfunction indications (e.g. on austenitic weld seams),

— indications due to geometry (e.g. in case of root concavity),

— complex geometries (e.g. fitting weld seams), or

— if a reduction in the radiation exposure of the test personnel can be attained in this way.

Ultrasonic test methods are defined for the validation of discontinuities (internal or surface open), requirements for the ultrasonic test equipment, for the preparation of test and device systems, for the implementation of the test and for the recording.

This document is applicable for the detection of indications by UT using normal-beam probes and anglebeam probes both in contact technique. Immersing technique and techniques for sizing are not in the scope of this document and should be independent qualified.

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.