Acoustic emission surveillance methods

This report was prepared for the Commission of European Communities - Nuclear Energy Agency (NEA - CREST) working group on Material and Mechanical Problems Related to the Safety Aspects of Steel Components in Nuclear Plants. It continues the report Risø-M-1429 under the same title. The present report is based on information received recently from fruitful collaboration within the Working Group, from the literature, and from personal experience and communications. The purpose is to present the status of the acoustic emission technique with respect to its application during proof testing, recurrent testing and service, of steel pressure vessels for nuclear plants. During proof testing it is evident that the location of acoustic emission sources can be carried out very reliably. The problem of warning against catastrophic failure cannot at present be given a clear answer, although an experienced operator can make an approach to the problem and very promising investigations are in progress.
During recurrent inspection it should be possible to gain further information on the state of the steel structure by applying the acoustic emission technique if the structure is accessible. Not much experience has been gained of acoustic emission surveillance during service in terms of Signature Analysis, but very promising investigations are in progress to solve the various problems, by using the acoustic emission technique in the hostile environment of a nuclear reactor.