Experimental estimation of the effect of contact condensation of steam-gas mixture on the VVER passive safety systems operation
The paper presents the results of experimental study of the effect of contact condensation of steam-gas mixture on the operation of VVER passive safety systems and the steam generator in emergency condensing mode. The contact condensation takes place when subcooled fluid is supplied in the accumulator tank of VVER reactor facility passive core flooding system (the HA-2 system) in the presence of non-condensable gases. Water supplied to the second stage of hydro accumulators can be used for increasing the operating time of the VVER steam generator in the emergency condensing mode and ensuring longer core cooling. Low liquid outlet velocity (less than 1 m/sec), necessitated to ensure safety systems operation in passive mode constitutes the distinguishing feature of the investigated processes.
The experiments were performed on the test facility with the parameters specific to the primary circuit of the reactor facility within 24 hours after the accident initiation for different concentrations of gas in the steam-gas mixture. Nitrogen and helium, which replaces hydrogen, were used as the non-condensable gases. It was established as the result of the experiments that the increase of concentration of non-condensable gas in the volume the HA-2 hydro accumulator model up to 45% leads to the reduction of intensity of contact condensation of steam from the steam-gas mixture by ~29% in the experiment with nitrogen and by ~57% in the experiment with helium. The obtained experimental data can be used for numerical simulation of emergency processes in the VVER reactor facility during operation of passive safety systems taking into account the removal of steam-gas mixture from steam generator by supplying the subcooled liquid jet into the volume of second stage HA-2 accumulator tanks.
- Kalyakin S.G., Sorokin A.P., Pivovarov V.A., Pometko R.S., Selivanov Yu.F., Morozov A.V., Remizov O.V. Eksperimentalnye issledovaniya teplofizicheskikh protsessov v obosnovanie bezopasnosti VVER novogo pokoleniya [Experimental studies of the thermal physical processes in justification of safety of the new generation of VVER]. Atomnaya Energiya. 2014, v. 116, no. 4, pp. 241-246 (in Russian).
- Morozov A.V. Teplogidravlicheskoe obosnovanie rabotosposobnosti sistemy passivnogo zaliva aktivnoj zony reaktora VVER. Diss. kand. tekhn. nauk [Thermohydraulic substantiation of the operation of passive core flooding system of the VVER reactor. Cand. tech. sci. diss.]. Obninsk, 2004. 159 p. (in Russian).
- Morozov A.V., Remizov O.V. Eksperimentalnoe obosnovanie proektnykh funktsiy dopolnitelnoy sistemy passivnogo zaliva aktivnoy zony reaktora VVER [Experimental substantiation of the design features of passive core flooding system of the VVER reactor]. Teploenergetika. 2012, no. 5, pp. 22-27 (in Russian).
- Lukyanov A.A., Zaitsev A.A., Morozov A.V., Popova T.V., Remizov O.V., Tsyganok A.A., Kalyakin D.S. Raschetno-eksperimentalnoe issledovanie vliyaniya nekondensiruyuschikhsya gazov na rabotu modeli parogeneratora VVER v kondensatsionnom rezhime pri zaproektnoy avarii [Numerical and experimental investigation of the effect of non-condensable gases on the VVER steam generator model operation in condensing mode during beyond design basis accident]. Izvestiya vuzov. Yadernaya energetika. 2010, no. 4, pp. 172-182 (in Russian).
- Maltsev M. Additional information on modern VVER Gen III technology. Proceedings of OECD/NEA Workshop on Innovations in Water-cooled Reactor Technologies, Paris, France, February 11-12, 2015.
- Berkovich V.M., Taranov G.S., Kalyakin S.G., Remizov O.V., Morozov A.V. Razrabotka i obosnovanie tekhnologii udaleniya nekondensiruyuschikhsya gazov dlya obespecheniya rabotosposobnosti sistemy passivnogo otvoda tepla [The development and substantiation of technology for removal of non-condensable gases to ensure operability of the passive heat removal system]. Atomnaya Energiya. 2006, v. 100, no. 1, pp. 13-19 (in Russian).
- Kopytov I.I., Kalyakin S.G., Berkovich V.M., Morozov A.V., Remizov O.V. Experimental investigation of non-condensable gases effect on Novovoronezh NPP-2 steam generator condensation power under the condition of passive safety systems operation. Proceedings of the 17-th International Conference on Nuclear Engineering 2009, ICONE17. Brussels, 2009, pp. 735-743.
- Isachenko V.P. Teploobmen pri kondensatsii [Heat transfer in the condensation]. Moscow. Energiya Publ., 1977, 240 p. (in Russian).
- Kutateladze S.S. Teploperedacha pri kondensatsii i kipenii [Heat transfer in the condensation and boiling]. Moscow. Mashgiz Publ., 1952, 234 p. (in Russian).
- Levich V.G. Fiziko-khimicheskaya gidrodinamika [Physical and chemical hydrodynamics]. Moscow. Gosudarstvennoe izdatelstvo fiziko-matematicheskoy literatury Publ., 1959. 700 p. (in Russian).
- E. Kulic, E. Rhodes. Heat transfer rate to moving droplets in air/steam mixtures. Proceedings of 6-th International Heat Transfer Conference, Toronto, 1978, v.1, pp. 469-474.
- Prandtl’ L. Gidroaeromekhanika [Aerohydromechanics]. Izhevsk, NIТS «Regulyarnaya i khaoticheskaya dinamika» Publ., 2000. 576 p. (in Russian).
- Ivanov V.I. Teplootdacha pri kondensatsii para na sploshnykh struyakh zhidkosti v kondensatorakh smeshivayuschego tipa. Diss. kand. tekhn. nauk [Heat transfer in the steam condensation on the continuous liquid jets in the condensers of the mixing type. Cand. tech. sci. diss.]. Saint Petersburg, 1993. 177 p.
- Berman L.D., Gordon B.G., Bogdan S.N. Teplootdacha ot parovozdushnoy smesi k dispergirovannoy vodyanoy strue v ogranichennom ob”yome [Heat transfer from the steam-air mixture to the dispersed water jet within a limited volume]. Teploenergetika. 1981, no. 12, pp. 38-42 (in Russian).
- E. Porcheron, P. Lemaitre, A. Nuboer, V. Roshas, J. Vendel. Experimental investigation in the TOSQAN facility of heat and mass transfers in a spray for containment application. Nuclear Engineering and Design. 2007, v. 237, pp. 1862-1871.
- M. Takahashi, A.K. Nayak, H. Murakoso, S. Kitagawa. Study on vapor condensation heat transfer on liquid spray. Proceedings of 7-th International Conference on Nuclear Engineering, ICONE-7481. Tokyo, Japan, April 19-23, 1999.
- Morozov A.V., Sakhipgareev A.R. Study of the effect of steam condensation from the steam-gas mixture on the liquid jet on VVER steam generator operation in condensation mode. VANT. Ser.: «Nuclear and reactor constants». 2016, no. 3, pp. 100-110 (in Russian).
- Berkovich V.M., Peresadko V.G., Taranov G.S., Remizov O.V., Morozov A.V., Tsyganok A.A., Kalyakin D.S. Experimental study on Novovoronezh NPP-2 steam generator model condensation power in the event of the beyond design basis accident. Proceedings of International Congress on Advances in Nuclear Power Plants 2010, ICAPP 2010. San Diego, CA, 2010, pp. 186-192.
- Morozov A.V., Remizov O.V. Eksperimentalnoe issledovanie raboty modeli parogeneratora VVER v kondensatsionnom rezhime [Experimental study of the model of the VVER steam generator in condensation mode]. Teploenergetika. 2012, no. 5, pp. 16-21 (in Russian).