After an initial engineering evaluation, each reportable event is assigned to one of the four individual reporting categories as given by the Nuclear Safety Officer and Reporting Ordinance (AtSMV). These categories particularly take into account the aspect that the authority has to be able to take  precautionary measures irrespective of the actual significance of the event.

Category S  (immediate report - reporting deadline: without delay)

Category E    (quick report - reporting deadline: within 24 hours)

Although events in Category E do not call for an immediate action by the  supervisory authority, safety reasons require that their cause is identified and that remedial action be taken within an appropriately short time period. These are, in general, events that may have a potential - but no direct - significance to safety.

Category N    (normal report - reporting deadline: within 5 days)

Category N is for events with a low significance to safety. They are only slightly different from routine operational events while plant conditions and operation remain in full accord with the operating instructions. These events are, nevertheless, systematically evaluated with the purpose of detecting possible weak points at an early stage.

Category V    (before initial core loading - reporting deadline: within 10 days)

This category V is used for events occurring during erection and commissioning of the nuclear power plant of which the supervisory authority should be  informed with regard to the later safe operation of the plant.