Morozov A.V., Kalyakin D.S., Sakhipgareev A.R., Shlepkin A.S., Soshkina A.S.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
The results of experimental and computational studies aimed at substantiating on the operability of passive core cooling systems of the WWER reactor, and as well as improving their design characteristics is considered in the article. The special attention is focused to issues related to the improvement of the passive core cooling systems in case of out-of-design accidents (e.a. Loss-of-coolant accident and blackout) for the safety justification of new projects of WWER. The reactor core is in a boiling state at this time. It is possible to increase boric acid amount in the coolant of the core given its low concentration in the steam phase. It is also possible to achieve conditions for crystallization boric acid boon the outer surface of fuel rods which can lead to deterioration of the heat removal. Another topical problem is the effect of non-condensable gases on the operation of the WWER steam generator in the condensation mode when the steam-gas mixture is stopped of removal from the steam generator tube bundle. The data obtained can be used for computational modeling of emergency processes in nuclear power plants with the WWER reactor during operation of the complex of passive safety systems (HA-2, HA-3, PHRS systems).
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