Pityk A.V., Sakhipgareev A.R., Shlepkin A.S., Morozov A.V.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
The results of experimental studies of the thermophysical properties (density and kinematic viscosity) of boric acid solutions in the concentration range 2.5-400 g/kg H2O at a temperature of 289-403 K is considered in the article. The problem of boric acid accumulation and crystallization in case of the accidents with main coolant circuit rupture and operation of passive safety systems (the hydroaccumulators systems of the first, second and third stages, as well as the passive heat removal system) is formulated. The review of the available literature data about thermal physical properties of the boric acid solution (density, viscosity and thermal conductivity) is presented. The fact that available data are of a general nature and does not cover the entire parameters range (temperature, pressure and concentration of acid) specific for the possible accidents at NPP with WWER is established. The methods of experimental research are described. Two stages of experimental studies of boric acid solutions density are presented: measurements at atmospheric pressure and at parameters characteristic for NPPs with WWER emergency modes. A description of a experimental facility used to the den-sity measure of highly concentrated boric acid solutions is presented. The operability of the given plant is proved by comparing the corresponding results obtained by the pycnometric method and by means of the setup. Experimental values of the kinematic viscosity of boric acid solutions in the concentration range 2.5-200 g/kg H2O at a temperature of 289-363 K are obtained by capillary viscosimetry method. The approximating dependences for the density and kinematic viscosity experimental values of the boric acid aqueous solutions are obtained.
1. Baranov V.Yu. Izotopy. Svojstva, poluchenie, primenenie [Isotopes. Properties, production, application]. Moscow, Fizmatlit Publ., 2005. 600 p.
2. Kalyakin S.G., Remizov O.V., Morozov A.V., Yur'ev Yu.S., Klimanova Yu.V. Obosnovanie proektnykh funktsij sistemy passivnogo zaliva GE-2 usovershenstvovannogo proekta AES s reaktorom VVER [Substantiation of Design Functions of the Passive Flood System for Improved NPP Project with VVER Reactor]. Izvestiya vuzov. Yadernaya energetika - Proseedings of Universities. Nuclear Power Engineering, 2003, no. 2, pp. 94–101.
3. Remizov O.V., Morozov A.V, Tsyganok A.A. Eksperimental'noe issledovanie neravnovesnykh teplogidravlicheskikh protsessov v sisteme passivnogo zaliva aktivnoj zony reaktora VVER [Experimental Study of Non-equilibrium Thermal-hydraulic Processes in a Passive VVER Core Reflooding System]. Izvestiya vuzov. Yadernaya energetika - Proseedings of Universities. Nuclear Power Engineering, 2009, no. 4, pp. 115-123.
4. Morozov A.V., Remizov O.V. Eksperimental'noe obosnovanie proektnykh funktsij dopolnitel'noj sistemy passivnogo zaliva aktivnoj zony reaktora VVER [Experimental substantiation of the design features of passive core flooding system of the VVER reactor]. Teploenergetika - Thermal Engineering, 2012, no. 5, pp. 22–27.
5. 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 of removal of non-condensable gases to ensure of the operation passive heat removal system]. Atomnaya energiya - Atomic Energy, 2006, vol. 100, no. 1, pp. 13-19.
6. Luk'yanov A.A., Zajtsev A.A., Morozov A.V., Popova T.V., Remizov O.V., Tsyganok A.A., Kalyakin D.S. Raschetno-eksperimental'noe issledovanie vliyaniya nekondensiruyuschihsya gazov na rabotu modeli parogeneratora VVER v kondensacionnom rezhime pri zaproektnoj 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 - Proseedings of Universities. Nuclear Power Engineering, 2010, no. 4, pp. 172-182.
7. Morozov A.V., Remizov O.V., Tsyganok A.A. Non-condensable gases effect on steam condensation heat transfer in horizontal tube bundle. Transactions of the American Nuclear Society 2010 ANS Annual Meeting and Embedded Topical Meetings. San Diego, CA, USA, 2010. pp. 676–677.
8. 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. Proc. Int. Congress on Advances in Nuclear Power Plants 2010, ICAPP 2010. San Diego, CA, 2010. pp. 186–192.
9. Kalyakin S.G., Sorokin A.P., Pivovarov V.A., Pomet'ko R.S., Selivanov Yu.F., Morozov A.V., Remizov O.V. Eksperimental'nye issledovaniya teplofizicheskikh protsessov v obosnovanie bezopasnosti VVER novogo pokoleniya [Experimental studies of the thermophysical processes in justification of the safety of the new generation of VVER]. Atomnaya energiya - Atomic Energy, 2014, vol. 116, no. 4, pp. 241-246.
10. Morozov A.V., Sorokin A.P., Ragulin S.V., Pityk A.V., Sakhipgareev A.R., Soshkina A.S., Shlepkin A.S. Vliyanie protsessov massoperenosa bornoj kisloty na ee nakoplenie v aktivnoj zone pri avarijnykh rezhimakh AES s VVER [Effect of Boric Acid Mass Transfer on the Accumulation Thereof in a Fuel Core under Emergency Modes at NPPs with WMR]. Teploenergetika - Thermal Engineering, 2017, no. 7, pp. 1-6.
11. Morozov A.V., Pityk A.V., Ragulin S.V., Sakhipgareev A.R., Soshkina A.S., Shlepkin A.S. Otsenka vliyaniya kapel'nogo unosa bornoj kisloty na ee nakoplenie v reaktore VVER v sluchae avarii [Estimation of influence of boric acid drop entrainment to its accumulation in the WWER reactor in the case of accident]. Izvestiya vuzov. Yadernaya energetika - Proseedings of Universities. Nuclear Power Engineering, 2017, no. 4, pp. 72-82.
12. Azizov N.D., Akhundov T.S. Termicheskie svojstva vodnykh rastvorov bornoj kisloty pri 298-573 K [Thermal properties of aqueous solutions of boric acid at 298-573 K]. Teplofizika vysokikh temperatur - High Temperature, 1996, vol. 34, no. 5, pp. 798-802.
13. Summary of Tests to Determine the Physical Properties of Buffered and Unbuffered Boric Acid Solutions. WCAP-17021-NP, Rev. 1 March 2009.
14. Avanesyan A.S., Akhundov T.S. Eksperimental'noe issledovanie koeffitsienta dinamicheskoj vyazkosti vodnykh rastvorov bornoj kisloty [Experimental study of the coefficient of dynamic viscosity of aqueous solutions of boric acid]. Erevan, AN ArmSSR Publ., 1980.
15. Gusejnov G.G., Gusejnov E.G. Issledovanie teploprovodnosti vodnykh rastvorov elektrolitov i poristykh materialov, nasyschkhennykh flyuidom [Investigation of the thermal conductivity of aqueous solutions of electrolytes and porous materials saturated with fluid]. Baki. Fizika. Elm., 2007, vol. 13, no. 1-2, pp. 13-25.
16. Yassin A.Hassan, Serdar Osturk, Saya Lee. Rheological characterization of buffered boric acid aqueous solutions in light water reactors. Progress in Nuclear Engineering, 2015, vol. 85, pp. 239–253.
17. Tuunanen J., Tuomisto J., Raussi P. Experimental and analytical studies of boric acid concentrations in a VVER-440 reactor during the long-term cooling period of loss-of coolant accidents. Nuclear Engineering and Design, 1992, vol. 148, pp. 217–231.
