There are several VVER-440/213* type nuclear power plants operating in the Czech Republic, Hungary, Slovak Republic, Russia and Ukraine. VVER-440/213 pressurised water reactors (PWRs) have a pressure suppression containment structure called a bubbler condenser (BC) tower which can reduce the design pressure of the entire confinement volume following a design-basis accident (DBA), such as a loss-of-coolant accident (LOCA). The bubbler condenser pressure suppression system reduces the LOCA confinement pressure by expanding the released steam to a large volume and allowing it to condense in a water pool. The thermodynamic principle of the bubbler condenser function is identical to the function of the containments in western boiling water reactors (BWRs) with pressure suppression systems, but the boundary conditions (construction and dimensions) are different.
The Bubbler Condenser Project was set up to provide answers to questions about the BC tower's performance under accident conditions by means of experiments carried out at the Electrogorsk Research and Engineering Centre (EREC) in Russia. Experts from the Czech Republic, France, Germany, Hungary, Slovak Republic and the United States participated in the project; the European Union also participated. Czech, Hungarian and Slovak utilities provided the financing for the test programme.
Project meetings held in 2001 and 2002 addressed research status on the subject, agreement on the experiments to be carried out and oversight on the co-ordination of these experiments with other initiatives, notably those handled by European Union. The three experiments that were agreed upon as a result of the project meetings were completed, the results analysed and an activity report published. Based on the tests, the project's steering group concluded that the related loads during DBAs do not represent a challenge to the bubbler condenser's confinement integrity.
Czech Republic, France, Germany, Hungary, Russia, Slovak Republic, Ukraine and United States