Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Features of Methods for Monitoring the Tightness of the Cladding of Fuel Elements in Fast Breeder Reactors with Lead Coolant

9/23/2021 2021 - #03 Global safety, reliability and diagnostics of nuclear power installations

Dragunova A.V. Morkin M.S. Perevezentsev V.V.

DOI: https://doi.org/10.26583/npe.2021.3.07

UDC: 621.039.564.5

For the timely detection of unpressurized fuel elements in the reactor, a system for monitoring the tightness of the fuel element cladding should be provided. In reactors with a heavy liquid metal coolant, the most effective is the control of the tightness of the cladding of fuel elements by detecting gaseous fission products.

The paper considers the basic principles of constructing a system for monitoring the tightness of fuel element cladding in reactors with a liquid metal coolant based on the detection of fission products and delayed neutrons. It is noted that in reactors with a heavy liquid&metal coolant the most effective is the control of the tightness of the cladding of fuel elements by gaseous fission products. Various aspects of the behavior of fission products in a reactor with a heavy liquid metal coolant are shown such as the movement of gaseous fission products in dissolved and bubble form along the circuit, sorption of volatile fission products in the lead coolant and on the surfaces of the structural elements, degassing of the gaseous fission products dissolved in the lead coolant and filtration of cover gas from aerosol particles of various nature.

General concepts of the transfer of gaseous fission products in a lead coolant and a mathematical model are described, which makes it possible to determine the calculated activity of reference radionuclides in each block of the reactor at any time after the depressurization of the fuel element. On the basis of this model, methods for monitoring the tightness of the fuel element cladding by the gas activity in the gas volumes of the reactor plant will be proposed.

References

  1. Adamov E.O., Kaplienko A.V., Orlov V.V., Smirnov V.S., Lopatkin A.V. Lead-cooled fast reactor BREST: from concept to technology implementation. Atomnaya Energiya. 2020, no. 4, pp. 185-194 (in Russian).
  2. Adamov E.O., Dragunov Yu.G., Orlov V.V. Mechanical Engineering of Nuclear Technology. Moscow. Mashinostroenie Publ., 2005. 960 p. (in Russian).
  3. Federal’naya Sluzhba po Ekologicheskomu, Tekhnologicheskomu i Atomnomu Nadzoru. Nuclear Safety Rules for Reactor Facilities of Nuclear Power Plants. NP-082-07. Yadernaya i Radiatsionnaya Bezopasnost’. 2008, no. 1, pp. 52-77 (in Russian).
  4. Luk’yanov D.A., Albutova O.I. Method of localization of defective fuel assemblies in fast reactors. VANT. Ser. Yaderno8Reaktornye Konstanty. 2017, iss. 3, pp. 100-117 (in Russian).
  5. Luk’yanov D.A., Albutova O.I., Zverev I.D., Salyaev A.V., Fadeev I.D., Prokoptsov I.S., Mikhajlenko M.A., Gur’ev S.A. Computational and experimental substantiation of the sodium system for monitoring the tightness of the cladding of fuel elements of a promising commercial reactor. VANT. Ser. Yaderno8Reaktornye Konstanty. 2018, iss. 5, pp. 110-118 (in Russian).
  6. Dedul’ A.V., Kal’chenko V.V., Kolik M.V., Stepanov V.S., Gonchar N.I., Pankratov D.V., Trykov L.A., Efremov Yu.V., Yakunin S.N. Gamma spectrometry of shielding gas of the primary circuit of RP with HLMC as a means of operational monitoring of tightness of fuel element cladding and heat exchange surface of a steam generator. VANT. Ser. Obespechenie Bezopasnosti AES. 2009, iss. 24, pp. 44-50 (in Russian).
  7. Gonchar N.I. Influence of uranium and thorium impurities in HLMC and structural materials of the core on the efficiency of fuel element cladding tightness control. VANT. Ser. Yaderno8Reaktornye Konstanty. 2018, iss. 5, pp. 176-184 (in Russian).
  8. Putilov K.A. Physics Course. Volume I. Mechanics, Acoustics, Molecular Physics, Thermodynamics. Moscow. Fizmatgiz Publ., 1963, 560 p. (in Russian).
  9. Skovorod’ko S.N., Mozgovoj A.G. Solubility of inert gases in heavy liquid metal coolants at high temperatures. Teplofizika Vysokih Temperatur. 2010, no. 4, pp. 633-637 (in Russian).
  10. Solubility data series. Volume 2. Krypton, xenon and radon – Gas Solubilities. Great Britain. Pergamon press, 1979, p. XVIII.
  11. Vereschagina T.N., Lemehov V.V., Morkin M.S. Lead-cooled gas lift probe hydraulics. Proc. of the Sci.8Techn. Conf. «Thermophysics82020». Obninsk. GNTs RF-FEI Publ., 2020, p. 136 (in Russian).
  12. Fedotovskij V.S., Vereschagina T.N., Orlov Yu.I. Model of coagulation of bubbles introduced by a jet injector into a flow of a heavy liquid-metal coolant. Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika. 2007, no. 1, pp. 92-102 (in Russian).
  13. Uollis G. One8Dimensional Two8Phase Flows. Moscow. Mir Publ., 1972, 440 p. (in Russian).
  14. Naumov V.S., Konovalov E.E. Sorption of radionuclides formed in the primary circuits of reactors with Pb-Bi coolant, the surface of structural materials of the core. Radiokhimiya. 2018, no. 2, pp. 167-174 (in Russian).
  15. SanPiN 2.6.1.24-03. Sanitary rules for the design and operation of nuclear power plants (SP AS-03). Available at: https://docs.cntd.ru/document/901862274 (accessed Mar. 17, 2021) (in Russian).
  16. Mikhajlov A.Yu., Gonchar N.I. Determination of the degassing characteristics of the liquid metal coolant of the primary circuit. Proc. of the Sci.8Techn. Conf. «Thermal Physics of Fast Nuclear Reactors (Thermophysics82014)». Obninsk. GNTs RF-FEI Publ., 2015, pp. 437-444 (in Russian).
  17. Babichev A.P., Babushkina N.A., Bratkovskij A.M. Physical Quantities: Handbook. Moscow. Energoatomizdat Publ., 1991, 1232 p. (in Russian).
  18. Handbook on Lead8Bismuth Eutectic Alloy and Lead Properties, Materials Compatibility, Thermal8hydraulics and Technologies. France. Nuclear Energy Agency Organization for Economic Co-Operation and Development Publ., 2015, 168 p.
  19. Vasyuhno V.P., Dubenkov N.E., Lemekhov V.V., Morkin M.S., Hacheresov G.A., Rychkov V.S., Shushlebin V.V. Investigation of the processes of mass transfer of fuel fission products and activation products of lead coolant impurities at a complex of lead-gas loop installations. Proc. of the Conf. «Nuclear innovations». Moscow. NIKIET JSC Publ., 2017, pp. 322-330 (in Russian).
  20. Martynov P.N., Posazhennikov A.M., Yagodkin I.V. Investigation of the behavior of aerosols in the gas circuits of reactor plants with a heavy coolant. Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika. 2007, no. 1, pp. 152-158 (in Russian).
  21. Posazhennikov A.M., Yagodkin I.V., Papovyants A.K., Grishin A.G., Isaev A. Yu. Cleaning of protective gas from aerosols of heavy liquid metal coolants. VANT. Ser. Yaderno8Reaktornye Konstanty. 2015, iss. 2, pp. 102-119 (in Russian).
  22. Veselkin A.P., Egorov Yu.A. Engineering Calculation of the Protection of Nuclear Power Plants. Moscow. Atomizdat Publ., 1976, 296 p. (in Russian).

BREST fuel-element cladding tightness monitoring lead coolant fuel element cladding defect fission products inert radioactive gases two-phase flows bubbling up diffusion degassing mathematical model