Izvestiya vuzov. Yadernaya Energetika

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

Ultrasonic Monitoring of the VVER-1000 FA Form Change

3/20/2021 2022 - #01 Global safety, reliability and diagnostics of nuclear power installations

Voronina A.V. Pavlov S.V. Amosov S.V.

DOI: https://doi.org/10.26583/npe.2022.1.06

UDC: 621.039.546.8

A procedure has been developed to determine the geometrical parameters of fuel assemblies (FA) by an ultrasonic pulse-echo technique used for all types of light-water reactor FAs. The measurement of geometrical parameters is achieved through the pairwise installation of ultrasonic sensors opposite the FA spacer grid faces at a distance of not more than a half of the sensor acoustic field near-region length such that the acoustic axes of the pairwise sensors are parallel to each other. The advantages of the presented technique is that it enables monitoring of any FA modifications, including the VVER reactor assemblies with a different number of spacer grids.

The paper presents a mathematical model of the acoustic path developed in a geometrical acoustics approximation and its verification results. The model was used for computational and experimental studies of the ultrasonic test technique, and engineering formulas have been developed to calculate the errors of the sensor measurement of the distance to the FA surface. A software package has been developed to simulate the FA form change monitoring and can be used to design new monitoring systems.

The developed technique to determine the VVER-1000 FA geometrical parameters was introduced at units 1 and 2 of the Temelin NPP, the Czech Republic, for the TVSA-T FA form change monitoring. The successful use of the proposed technique makes it possible to recommend it for use in inspection benches at other NPPs

References

  1. Zvir E.A., Zhitelev V.A., Zaharov A.V., Krjukov F.N., ShishinV.Yu. The main results of post-irradiation studies performed at SSC RIAR JSC in 2014-2018. Proc. of the XI Conference on Reactor Materials Science. Dimitrovgrad, 2019, pp. 5-8 (in Russian).
  2. Polenok V.S., Zhitelev V.A., Markov D.V., Zvir E.A., Shevljakov G.V., Kobyljanskij G.P. Post-reactor studies of VVER-1000 fuel assemblies of alternative designs. Collection of Papers of the SSC RIAR JSC. 2010, no. 3, pp. 10-15 (in Russian).
  3. Ivanov N.A., Bromirsky I.A., Sementsov A.V. Implementation of SIR fuel assemblies for new projects of NPP with VVER. Bulletin of the Main Scientific and Technical Works of OKB «Gidropress» for 2016. Podolsk. OKB Gidropress JSC Publ., 2017. Available at : http://www.gidropress.podolsk.ru/files/publication/yb-2016/documents/14.pdf (accessed Sep. 05, 2021) (in Russian).
  4. Ivanov N.A., Bromirsky I.A., Surov D.V., Pervushin L.A., Tishkov A.N., Sementsov A.V., Pavlov S.V., Amosov S.V. Stand for Inspection and Repair of Fuel Assemblies for NPP-2006 Project. Tyazhyoloe Mashinostroenie. 2017, no. 4, pp. 25-28 (in Russian).
  5. Voronina A.V. Analysis of the efficiency, reliability and safety of methods for determining the shape change of fuel assemblies of a VVER-1000 reactor at nuclear power plants. Proc. of the All-Russian Youth Conference «Scientific Research and Technological Development to Support the Development of New Generation Nuclear Technologies». Dimitrovgrad, 2018, pp. 62-64 (in Russian).
  6. Xu Yuanhuan, Nie Yong Distortion Measurement for Fuel Assemblies with Ultrasonic Technique. Proc. of the IAEA Technical Meeting held in Buenos Aires. Argentina, 2009, pp. 124-128.
  7. Martynenko S.P. TVSA Geometry Measurement System (SIGMA-TVSA) in VVER-1000 Conditions. The results of measurements on the NPP. Proc. of the Scientific and technical conference «New-generation nuclear fuel for nuclear power plants». Moscow, 2012 (in Russian).
  8. Aullo M., Aleshin Y., Messier J. Reduction of fuel assembly bow with the RFA fuel. TopFuel: Operation and Experience. Manchester, United Kingdom. European Nuclear Society, 2012.
  9. Pavlov S.V. Development of Methods and Tools for studying Fuel Assemblies and Fuel Rods of VVER Reactors in the Spent Fuel Pools of Nuclear Reactors. Cand. tech. sci. diss. Nizhny Novgorod, 2006. 126 p. (in Russian).
  10. Pavlov S.V., Voronina A.V. Design Solutions for Measurements of VVER-1000 Fuel Assembly Dimensional Changes by Ultrasonic Technique in Cooling Pool at Nuclear Power Plant. Vestnik Dimitrovgradskogo Inzhenerno-Tehnologicheskogo Instituta. 2021, no. 1, pp. 25-38 (in Russian).
  11. Amosov S.V., Pavlov S.V., Voronina A.V. , Pravdin D.I. Method of Ultrasonic Inspection of Parameters of Molding of Fuel Assemblies of Nuclear Reactors. Patent RF, no. 2738751, 2020 (in Russian).
  12. Voronina A.V., Pavlov S.V. Mathematical Model of an Acoustic Tract of an Echo-Pulse Method for Measurement of the Geometric Parameters of a Fuel Assembly of a Nuclear Reactor in the Geometric Acoustics Approximation. Vestnik Natsional’nogo Issledovatel’skogo Yadernogo Universiteta MIFI. 2020, v. 9, no. 3, pp. 217-225; DOI: https://doi.org/10.1134/S2304487X20030104 (in Russian).
  13. Pavlov S.V., Voronina A.V. Program for Calculating the Speed of Sound in Water near the Surface of a Vertical Heated Plate. Certificate of state registration of computer programs RF, no. 2018663116, 2018 (in Russian).
  14. ANSYS Fluent. Available at: http://www.fluent.com (accessed Sep. 05, 2021).
  15. Voronina A.V., Pavlov S.V. Selecting a Turbulence Model for Calculating the Temperature Profile at the Surface of VVER 1000 Fuel Assemblies in the NPP Spent Fuel Pool. Izvestija vuzov. Yadernaya Energetika. 2021, no. 1, pp. 83-94; DOI: https://doi.org/10.26583/npe.2021.1.08 (in Russian).
  16. Voronina A.V., Pavlov S.V. Verification of the Mathematical Model of the Acoustic Path of the Ultrasonic Method for Measuring Distances to a Heated Vertical Plate in the Presence Of Natural Convection. Izvestiya Vysshikh Uchebnykh Zavedenij. Povolzhskij Region. Tekhnicheskie Nauki. 2021, no. 2, pp. 63-76 (in Russian).
  17. Pavlov S.V., Shalaginova T.M., Mikhaylov S.V., Prokudanov D.L. Study of Natural Convection Effect on the Measurement Results of Geometrical Characteristics of Fuel Elements and Fuel Assemblies by Ultrasonic Methods in spent pools. Preprint. Dimitrovgrad. NIIAR Publ., 1991, 28 p. (in Russian).
  18. Voronina A.V., Pavlov S.V. Engineering Formulas for Estimating the Influence of Natural Convection along the Surface of Fuel Assembly of VVER-1000 on the Results of Measuring its Sizes by the Ultrasonic Method in Cooling Pond of Nuclear Power Plant. VANT. Ser. Yadern-Reaktornye Konstanty, 2021, no. 1, pp. 74-85 (in Russian).
  19. Safety Guide «Radiation, Thermal and Physical Characteristics of Spent Nuclear Fuel from Water-Moderated Power Reactors and High Power Channel-Type Reactors». Approved by Order of the Federal Environmental, Industrial and Nuclear Supervision Service No. 106 dated March 11, 2020 (in Russian).
  20. Pavlov S.V., Voronina A.V. Program for Simulation of VVER 1000 Fuel Assembly Bow Measurements by Ultrasonic Echo-Pulse Method. Certificate of state registration of computer programs RF, no. 2021616486, 2021 (in Russian).
  21. Voronina A.V., Pavlov S.V. Numerical Simulation of VVER 1000 Fuel Assembly Bow Measurements in Cooling Pool at Nuclear Power Plant. Vestnik Dimitrovgradskogo Inzhenerno-Tehnologicheskogo Instituta, 2021, no. 1, pp. 15-24 (in Russian).

ultrasonic technique fuel assembly form change model natural convection