NUMERICAL AND EXPERIMENTAL STUDY OF THE NATURAL CIRCULATION MODE DURING COMMISSIONING UNIT-1 NOVOVORONEZH NPP-2
29th Symposium of AER on VVER Reactor Physics and Reactor Safety (2019, Energoland, Mochovce NPP, Slovakia)
reactor physics experiments and code validation
Abstract
Natural circulation of the coolant is an important component of ensuring safety and core cooling in conditions when forced flowrate is lossed. Unit 1 of Novovoronezh NPP-2 is the leading unit of the new NPP-2006 project with VVER-1200. When commissioning this power unit, tests were conducted for the first time to verify the natural circulation mode, confirming both the development of this mode while simultaneously shutting down all the MCPs, and as the design value of the permissible reactor power level in this mode.
Due to the significance of the obtained experimental data during the commissioning tests and the need for validation of the calculation model for NPP-2006 project which is used in the calculations for the safety justification, a numerical and experimental study of the natural circulation mode was carried out. This study was jointly conducted by experts from the filial “Novovoronezhatomtechenergo” of the JSC “Atomtechenergo” and the National Research Center “Kurchatov Institute”, taking into account their specializations. The basis of this study was a comparison and analysis of experimental and calculated data.
The main study results are presented. Conclusions and suggestions on the practical use of these results are given.