The Chernobyl Sarcophagus Project of the German-French Initiative

Abstract

After the declaration of Germany and France at the Vienna Chernobyl Conference in April 1996 to support the international co-operation of institutions of the Ukraine, Belarus and Russia in view of a solution of the Chernobyl related issues, three project were identified, i.e. the safety state of the Chernobyl Sarcophagus, the radioecological consequences due to the radioactive contaminated areas and the health consequences of the liquidators and the population in Ukraine, Belarus and Russia after the Chernobyl accident. The projects are funded by the governments and by the electricity utilities of Germany and France, respectively. In this paper the Sarcophagus project will be presented. Fifteen years after the accident of Unit 4 of the Chernobyl NPP the Sarcophagus still remains one of the most dangerous nuclear facilities in the world. The ruin of the destroyed Unit 4 and its surrounding Sarcophagus together are termed object Shelter. The Sarcophagus was erected in a relatively short time period of several months on the basements of old structures of unknown stability of the former unit 4. Inside the Shelter remained about 96 % of the irradiated nuclear fuel inventory of the reactor of unit 4 before the accident, i.e. 180 t of Uranium of total radioactivity 7 × 10¹⁷ Bq. The radioactive releases to the industrial site of 500 m radius around the Chernobyl NPP during the first ten days after the accident were estimated to amount 0,5–1,0 % of the fuel inventory. The spent fuel inside the Shelter and the radioactive contamination at the industrial site have an essential impact on all human activities concerned with investigation work, maintenance and stabilizing measures which are presently under progress e.g. in the framework of the Shelter Implementation Plan because of the radiation exposure. For planning of any actions towards a stabilizing of the unstable building constructions of the Shelter and of measures to retain the radioactive materials inside the Sarcophagus a unified and comprehensive database of all safety relevant technical data describing the present safety state of the Shelter is required. Hence, the main aim of the Shelter project is the collection, analysis and selection as well as verification of all existing safety relevant data of the Shelter and the creation of an appropriate database. The database will be useful for different applications, e.g. for performing stabilizing measures in the framework of the Shelter Implementation Plan (SIP) or for the corresponding licensing procedure of the national authority of Ukraine.