The fourth project annual technical meeting on in-vessel melt retention (IVMR 4th Project Annual Meetings) was held in early June in the city of Trnava (Slovakia). The State Scientific and Technical Center for Nuclear and Radiation Safety is an associate member of this project and is directly involved into its implementation.
Thanks to the participation in this project, SSTC NRS was able to compare the approaches and tools to assess possible strategy for in-vessel melt retention. This allows retaining safety barrier integrity and significantly reducing radioactive substance release during possible severe accident at nuclear power plants.
The participants – representatives from Ukraine, France, Germany, Hungary, Korea, Sweden, Spain, Italy, Belgium, the Czech Republic, Slovakia, Finland, Russia discussed during the meeting the theoretical research results related to modeling of in-vessel melt retention, experimental research related to obtaining a critical heat flux on the outer surface of the reactor vessel and related to melt behavior and stratification. We considered specific examples of the application of this strategy at nuclear power plants and defined future plans.
“Ukraine is planning to modernize operating VVER-440 and install RPV external cooling system. This severe accident management strategy is considered possible for VVER-1000. The experimental data on possible cooling of VVER-1000 from the outside are especially important to justify the success of this strategy. Such experimental data will be obtained during the project completion approximately by the end of 2019 when final reports resulting from the experiments will be available”, the head of laboratory in NPP thermal hydraulic and probabilistic safety analysis department, SSTC NRS Yurii Vorobiov stated.