Peculiarities of residual radiation formation of disperse micro encapsulated nuclear fuel
Researches in the field of physics of nuclear fuel of new generation are being carried out at present at National research Tomsk polytechnic university. The fuel being developed is a graphite matrix with micro encapsulated fuel (microfuel) of spherical shape in it. The main technological application of these researches is creation of low-power high temperature gas-cooled thorium reactor unit. The researchers are of great significance and are generally paid much attention to.
In the present paper a calculated analysis of different configurations of thorium reactor core loading is described. Neutron-physical researches and fuel isotopic composition calculation were made. Alpha-emitters, sources of neutron and photon radiation were analyzed. A calculation instrument which allows evaluating radiation characteristics of nuclear fuel at the reactor designing stage was developed. It also makes it possible to reconsider usual procedures of handling new and irradiated nuclear fuel in a nuclear fuel cycle of new generation.
The main attention in the research was paid to the calculation of neutron yield and spectrum formed as a result of (alpha, n)-reactions on light nuclei of microfuel, as the concentration of various alpha-emitters resulting from irradiation is directly dependent on the fuel burn-up, while the concentration of (alpha, n)-neutrons depends on the configuration of microfuel, graphite matrix, concentration of light elements, and modifies the pattern of neutron diffusion flux.
To calculate the neutron yield, an analytical model and verified calculation codes were used. At the stage of calculation evaluation the use of an analytical model is considered a more preferable research method, as it allows calculating alpha-particles transport, when a corresponding code is not available. Besides, such approach can be used to prepare a file with input data for tasks of neutron-activation analysis, to calculate dosimetric characteristics of neutron isotopic sources and media, containing discrete particles of different shape, size and composition.
The researched were performed to create an effective calculation instrument used for initial evaluation of radiation characteristics of nuclear fuel in a nuclear fuel cycle of new generation.
An analytical model and verified calculation codes of the programs WIMS-D5B, SCALE 6.0, SOURCES-4C and SRIM-2013 were used.
The work was supported by Russian Science Foundation № 18-19-00136 of April 18, 2018. The subject: Scientific basis development of oxide compositions plasma-chemical synthesis technology for perspective nuclear fuel types.
- Shamanin I.V., Bedenko S.V., Chertkov Yu.B., Gubaydulin I.M. Gas-cooled thorium reactor with fuel block of the Unified design. Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika. 2015, no. 3, pp. 124-134 (in Russian).
- Shamanin I.V., Bedenko S.V., Chertkov Yu.B. Thorium-loaded low-power reactor installation operated with super-long fuel residence time. Izvestiya vuzov. Yadernaya Energetika. 2016, no. 2, pp. 121-132 (in Russian).
- Shamanin I.V., Grachev V.M., Chertkov Y.B., Bedenko S.V., Mendoza O., Knyshev V.V. Neutronic properties of high-temperature gas-cooled reactors with thorium fuel. Annals of Nuclear Energy. 2018, v. 113, pp. 286-293.
- Vlaskin G.N., Khomyakov Y.S., Bulanenko V.I. Neutron Yield of the Reaction (α, n) on Thick Targets Comprised of Light Elements. Atomic Energy. 2015, v. 117, no. 5, pp. 357-365 (in Russian).
- Bulanenko V.I. Neutron yield of (α, n)-reaction on oxygen. Atomnaya Energiya. 1979, v. 47, no. 1, pp. 531-534 (in Russian).
- Murata T., Shibata K. Evaluation of The (α, n)-reaction Nuclear Data for Light Nuclei. Journal of Nuclear Science and Technology. 2002, v. 39, pp. 76-79.
- West D., Sherwood A.C. Mesurments of Thick-Target (α, n) Yields from Light Elements. Annals of Nuclear Energy. 1982, v. 9, pp. 551-577.
- Dulin V.V., Zabrodskaya S.A. About Contribution of (α, n) Reaction to Intensity of Neutron Radiation of Dioxide of Plutonium. Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika. 2005, no. 4, pp. 18-24 (in Russian).
- Dulin V.V., Matveyenko I.P. Alpha-Rossi determination of deeply subcritical states of multiplying media. Izvestiya Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika. 2002, no. 1, pp. 9-18 (in Russian).
- Shamanin I.V., Bedenko S.V., Nesterov V.N., Lutsik I.O., Prets A.A. Solution of neutron-transport Multigroup equations system in subcritical systems. Izvestiya vuzov. Yadernaya Energetika. 2017, no. 4, pp. 38-49 (in Russian).
- Bogatov S.A., Mitenkova E.F., Novikov N.V. The radiation characteristics of the transport packages with vitrified high-level waste. Physics of Atomic Nuclei. 2015, v. 78, no. 11, pp. 1301-1308.
- Glukhov L.Y., Kotkov S.P., Kuznetsov M.S., Chursin S.S. Measurement of prompt neutron generation time at the VIR-2M pulsed nuclear reactor. Physics of Atomic Nuclei. 2016, v. 79, no. 8, pp. 1357-1361.
- Spirin E.V., Aleksakhin R.M., Vlaskin G.N., Utkin, S.S. Radiation Balance of Spent Nuclear Fuel of a Fast Reactor and Natural Uranium. Atomnaya Energiya. 2015, v. 119, no. 2, pp. 142-148 (in Russian).
- Wilson W.B., Perry R.T., Charlton W.S., Parish T.A. Sources: A code for calculating (alpha, n), spontaneous fission, and delayed neutron sources and spectra. Progress in Nuclear Energy. 2009, v. 51, no. 4-5, pp. 608-613.
- Vlaskin G., Khomiakov Y. Calculation of Neutron Production Rates and Spectra from Compounds of Actinides and Light Elements. EPJ Web of Conferences. 2017, v. 153, no. 07033.
- Leniau B., Wilson J. N. A new spent fuel source characterization code CHARS and its application to the shielding of the thorium. Progress in Nuclear Science and Technology. 2014, v. 4, pp. 134-137.
- Jacobs G.J.H., Liskien H. Energy Spectra of Neutrons Produced by α-Particles in Thick Targets of Light Elements. Annals of Nuclear Energy. 1983, v. 1983, no. 10, pp. 541-552.
- Ziegler J.F., Ziegler M.D., Biersack J.P. SRIM – The Stopping and Ranges of Ions in Matter. Nuclear Instruments and Methods in Physics Research B. 2010, v. 2010, no. 268, pp. 1818-1823.
- Bedenko S., Shamanin I., Grachev V., Knyshev V., Ukrainets O., Zorkin A. Neutron radiation characteristics of the IVth generation reactor spent fuel. AIP Conference Proceedings. 2018, v. 1938, no. 020001.
- Fomushkin E.F. Some characteristics of radiation distribution in the spherical active system. VANT. Ser. Fizika yadernykh reaktorov. 2010, v. 2010, no. 2, pp. 17-21 (in Russian).
- Bak M.A., Petrzhak K.A., Romanov Yu.F. Radiation of a spherical source in the presence of self-absorption. Zhurnal Tekhnicheskoy Fiziki. 1965, v. 26, no. 2, pp. 379-384 (in Russian).
- Chukbar B.K. Verification of statistical method CORN for modeling of microfuel in the case of high grain concentration. Physics of Atomic Nuclei. 2015, v. 78, no. 11, pp. 1200-1205.