Izvestiya vuzov. Yadernaya Energetika

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

Method for Measuring the Local Mass of Uranium in Uranium-Aluminum Targets for 99Mo Generation

12/14/2022 2022 - #04 applicationofnucleartech

Romanovskiy V.S. Malkov A.P. Kremer A.V. Kushnir Yu.A. Leonenko D.A. Leonenko A.A.

DOI: https://doi.org/10.26583/npe.2022.4.10

UDC: 539.1.074: 624.039

Specific purpose radionuclides for the needs of medicine, science and production sectors are generated by irradiating raw materials in nuclear reactors. The targets are used for 99Mo production by irradiation in RBT-10/2 and RBT-6 nuclear reactors of RIAR JSC (ROSATOM Scientific Division).Before irradiation, each target must be checked for uneven distribution of the starting material in order to avoid local overheating of the target shell with possible subsequent depressurization of the target. For measurements, the method of non-destructive analysis was used, based on the transmission of the target by radiation from an external radioactive source based on radionuclide 55Fe, emitting X-ray radiation with a continuous spectrum in the range of 30-220 keV. Since the reference irradiation spectrum is continuous, measurement of a sample results in a set (spectrum) of transmission coefficient values calculated for each channel of the analyzer. The calculated mass of the starting material value at the X-rayed core area corresponds to the transmission coefficient value of each channel. Averaging over a few tens of channel values measured simultaneously ensures measurement result reliability and accuracy. The results of measuring the target are the coefficient of uneven distribution of the starting material and the total mass of the nuclear material. A set of control samples and special isotope radiation sources have been developed and certified as metrological support for the measurement methodology. The spectrometric part of the installation is a scintillation detector with a NaI(Tl) crystal, the target is moved using a stepper motor and a horizontal belt drive module. The main characteristics of the error of the technique depending on the duration of exposure were established.


  1. Collective Use Center «Irradiation – Materials Science – Research Center». Available at: http://niiar.ru/support_centre (accessed Jul. 01, 2022) (in Russian).
  2. Reilly D., Ensslin N., and Smith H., Jr. Passive Non Destructive Assay of Nuclear Materials, NUREG /CR-5550, LA-UR-90-732, March 1991, 723 p. Available at: http://large.stanford.edu/courses/2012/ph241/bordia2/docs/ML091470585.pdf (accessed Jul. 01, 2022).
  3. Table of Radionuclides, Le Laboratoire National Henri Becquerel. Available at: http://www.nucleide.org/DDEP_WG/Nuclides/Fe-55_tables.pdf (accessed Jul. 01, 2022).
  4. Research Reactors of the Member States of the Commonwealth of Independent States. Moscow: Helios ARV Publ., 2016, 480 p. (in Russian).
  5. GOST 15484-81. Ionizing Radiation and its Measurements. Available at: https://docs.cntd.ru/document/1200015267 (accessed Jul. 01, 2022) (in Russian).
  6. GOST 25504-82. Closed Radionuclide Sources of Ionizing Radiation. Available at: https://protect.gost.ru/document.aspx?control=7&id=146483 (accessed Jul. 01, 2022) (in Russian).
  7. GOST R 51873-2002. Closed Radionuclide Sources of Ionizing Radiation. Available at: https://protect.gost.ru/document.aspx?control=7&id=130387 (accessed Jul. 01, 2022) (in Russian).
  8. GOST R 51919-2002. Closed Radionuclide Sources of Ionizing Radiation.Available at: https://protect.gost.ru/document.aspx?control=7&id=130631 (accessed Jul. 01, 2022) (in Russian).
  9. GOST R 52125-2003. Closed Radionuclide Sources of Ionizing Radiation. Available at: https:// protect.gost.ru/document.aspx?control=7&id=130194 (accessed Jul. 01, 2022) (in Russian).
  10. GOST R 52241-2004. Closed Radionuclide Sources of Ionizing Radiation. Available at: https://protect.gost.ru/document.aspx?control=7&id=129661 (accessed Jul. 01, 2022) (in Russian).
  11. Gmurman V.E. Guide to Solving Problems in Probability Theory and Mathematical Statistics. Moscow. Vysshaya Shkola Publ., 2004, 406 p. (in Russian).

radiation density measurement reactor target transmission spectrum X-ray source

Link for citing the article: Romanovskiy V.S., Malkov A.P., Kremer A.V., Kushnir Yu.A., Leonenko D.A., Leonenko A.A. Method for Measuring the Local Mass of Uranium in Uranium-Aluminum Targets for 99Mo Generation. Izvestiya vuzov. Yadernaya Energetika. 2022, no. 4, pp. 112-121; DOI: https://doi.org/10.26583/npe.2022.4.10 (in Russian).