Nuclear Accidents

5Management of the Post-accident Phase

5.1. Introduction

The IAEA [IAE 89a] distinguishes three phases following a major nuclear accident. The first one is an early phase, lasting a few hours, in which the main risk is inhaling contaminated air. The second one is an intermediate phase, from a few days to a few weeks, where the risks come from either external irradiation resulting from contaminated soils, internal irradiation as a result of inhalation of resuspended particles, or internal irradiation from the ingestion of contaminated water or food. Finally, the third one is a late phase, lasting several weeks to several years, where the main risk is related to the consumption of contaminated food or water and environmental contamination.

Since around the turn of the millennium, the trend has been to retain two phases in an accident: the emergency phase and the post-accident phase. The post-accident phase is generally divided into two periods. The first period is transitional and the second (very long) period corresponds to the post-accident phase itself. In each period, various actions must be taken. For example, in the case of France, the ASN has published elements of the doctrine for the post-accident management of a nuclear accident [ASN 12a].

Several authors introduce an additional initial period in the post-accident period, which is the end of the emergency phase. In this case, each of these three periods (or phases) has its own specificity. The initial phase is the implementation ...