At its May 2009 meeting, the WGOE identified transformer failures as an issue of generic importance. The US NRC had identified that transformer failures had an increasing trend. Transfortmers are non-safety related equipment. As such, the maintenance practices are generally outside of the regulatory purview.
In December 2009, the WGOE was granted CNRA approval for a task on transformer failures. A detailed questionnaire was developed for the member countries to contribute their operating experience on transformer failures.