History of serious accidents at nuclear facilities

The bachelor thesis maps all the accidents assessed by the INES scale level 5 and above. It is not only concerning events at nuclear power plants, but also at nuclear weapons production facilities, whose construction preceded the development of the nuclear power plants in several countries. An attention is paid also to the unfortunate event, which was originated as a result of unauthorized manipulation with a part of the radiotherapy device containing radioactive isotopes of caesium 137Cs. The theoretical part of the bachelor thesis explains the general concepts, such as radioactivity and ionizing radiation. It distinguishes the types and sources of ionizing radiations and describes its impact on human body. Next, it deals with the concept of nuclear safety, determined supervising authorities and its governing legislation. It also contains a description of the INES scale, which is an international scale used to assess nuclear incidents and accidents. The practical part of this thesis provides an overview of the accidents with a detailed description of their development, the circumstances that led to them and the consequences left behind. The development of the individual accidents is subsequently analysed with a view to discover the underlying causes, and finally compared in order to find possible identical features or similarities. The present thesis was intended to examine the following research question: Is human failure the most frequent cause of nuclear plant accidents