The Chernobyl Disaster in Ukraine. Experience in Overcoming the Consequences of Accident and "Shelter" Object Transformation to Safe System

Abstract

The report focuses on building aspects of state assessment of the Chernobyl NPP forth power unit building structures, damaged in the accident on the 26th of April, 1986, as well as newly constructed "Shelter" Object (SO) structures. In the report there are characteristics of damage of the Chernobyl NPP forth power unit, description of the structural scheme of "Shelter" Object and its current state. The measures on strengthening (stabilization) of the unstable structures, realized on "Shelter" Object, are considered and the basic provisions for Strategy of formation "Shelter" Object as an ecologically safe system are given. Attention is paid to stages of new safe confinement (NSC) concept selection and characteristics of the NSC and its basic objects are given. It took 25 years after the accident. During this time a lot of works on decontamination of the local zone territory, ensuring personnel and population radiation safety and strengthening of some unstable structures were realized. But the problem of the object safety is actual at present. The consequences of the nuclear accident on the ChNPP forth power unit have long-term danger for personnel, population and environment. In the report there is analysis and comparison of ChNPP and "Fukusima-1" Japanese NPP accident consequences; attention is paid to consequences of the unfavorable catastrophic natural phenomena influence.