In-Vessel Core Melt Retention (IVMR) strategy via external vessel cooling is widely applied for reactors of relatively low power like VVER-440. In this study IVRM strategy was applied for Rivne-1,2 units, to prove the pressure vessel integrity. Based on initial data like heat flux for internal wall and external wall temperature a series of calculations for different scenarios were performed. These calculations include non-elastic material behavior like creep and plasticity. As the result the wall ablation, radial displacements, stress and strains were obtained. To prove pressure vessel integrity four criterions have been checked. The first one is obvious - remaining wall thickness, to prove that that RPV won't be melted right through. The second one is viscoplastic collapse - lack of monotonous increase in deformations, in case of FEM solution result convergency can be interprated as resist against such failure. The third - sustainable external cooling, thus we have to be sure that gap between RPV(due to radial elongation) and thermal protection shield will be 10 mm at least. The last one is brittle strength, this calculation was performed on a separate model and accounted for RPV material degradation. Obtained results allowed to apply IVMR strategy for VVER-440 at Rivne-1,2 units by installing the cavity flooding system.


In-Vessel Core Melt Retention Strategy Applied for the Rivne VVER-440 Unit

Division / Sponsors: 
Power Division & Nuclear Engineering Division (NED)

Power Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/POWER/POWER2020/volume/83747

International Conference on Nuclear Engineering
Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE2020/volume/83761

POWER-ICONE - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.