R. P. Karagergi, A. V. Konovalov, A. V. Kozlov

VERIFICATION OF PLASTIC STRAIN VALUES DURING OVALIZATION OF A RING SPECIMEN FROM A FUEL ELEMENT SHELL OF A FAST NEUTRON REACTOR

Mechanical testing of ring specimens for radial compression between flat dies (ovalization) was carried out, supplemented by analyzing the stress-strain state calculated by a specialized computer program. To verify the values of plastic strain, laser marks were made on the side surface of the ring. It is found that the maximum plastic deformation accumulates at the inner and outer walls of the ring, where maximum tensile and compressive stresses act, respectively. The deviation of the experimental values of plastic strain from the predicted ones does not exceed 10%. It is shown that the analysis of the stress-strain state of the ring specimen during ovalization can be useful for evaluating the critical values of the mechanical characteristics of the shell material irradiated in a fast neutron reactor to a high damaging dose.

Acknowledgment: The work was performed under the state assignment from the Russian Ministry of Science and Higher Education (theme Structure, No. 122021000033-2), the state assignment for the IES UB RAS, R&D No. 124020600042-9, and the program of the Rosatom State Nuclear Energy Corporation on increasing the maximum fuel burnup in the fuel assemblies of fast neutron reactors.

References:

1. Barsanova, S.V., Kozlov, A.V., and Shilo, O.B. The effect of fast neutron irradiation on changes in the mechanical properties of austenitic steels EK–164 and ChS–68. Voprosy Atomnoy Nauki i Tekhniki. Seriya Materialovedenie i Novye Materialy, 2018, 5 (96), 4-12. (In Russian).
2. Garner, F.A. Radiation damage in austenitic steels. Comprehensive Nuclear Materials, 2012, 4, 33-95. DOI: 10.1016/b978-0-08-056033-5.00065-3.
3. Arsène, S. and Bai, J. A new approach to measuring transverse properties of structural tubing by a ring test – experimental investigation. Journal of Testing and Evaluation, 1998, 26 (1), 26–30. DOI: 10.1520/JTE11966J.
4. Grigoriev, V., Jakobsson, R., Josefsson, B., and Schrire, D. Advanced techniques for mechanical testing of irradiated cladding materials. In: Advanced Post-Irradiation Examination Techniques for Water Reactor Fuel: Proceedings of a Technical Committee Meeting, Dimitrovgrad, Russian Federation, 14–18 May 2001, IAEA, 2002, pp. 187–193.
5. Cohen, A.B., Majumdar, S., Ruther, W.E., Billone, M.C., Chung, H.M., and Neimark, L.A. Modified ring stretch tensile testing of Zr–1Nb cladding. In: Summary of paper for 25th Water Reactor Safety Information Meeting, NRC Office of Nuclear Regulatory Research, Bethesda, Maryland, October 20–22 1997, Energy Technology Division, Argonne National Laboratory, 1997.
6. Daum, R.S., Majumdar, S., Tsai, H., Bray, T.S., Koss, D.A., Motta, A.T., and Billone, M.C. Mechanical property testing of irradiated Zircaloy cladding under reactor transient conditions. In: Small Specimen Test Techniques, Fourth Volume, ASTM STP 1418, M.A. Sokolov, J.D. Landes, and G.E. Lucas, eds., American Society for Testing and Materials, West Conshohocken, PA, 2002. Available at: https://www.researchgate.net/publication/255271057_Mechanical_property_testing_of_irradiated_Zircaloy_cladding_under_reactor_transient_conditions
7. Desquines, J., Koss, D.A., Motta, A.T., Cazalis, B., and Petit, M. The issue of stress state during mechanical tests to assess cladding performance during a reactivity-initiated accident (RIA). Journal of Nuclear Materials, 2011, 412 250–267. DOI: 10.1016/j.jnucmat.2011.03.015.
8. Leontieva-Smirnova, M.V., Kalin, B.A., Morozov, E.M., Kostyukhina, A.V., Fedotov, P.V., and Taktashev, R.N. Methodical peculiarities of the ring specimens tensile tests. Fizika i Khimiya Obrabotki Materiaov, 2019, 6, 62–71. (In Russian). DOI: 10.30791/0015-3214-2019-6-62-71.
9. Gurovich, B.A., Frolov, A.S., and Fedotov, I.V. Improved evaluation of ring tensile test ductility applied to neutron irradiated 42XNM tubes in the temperature range of (500-1100)°C. Nuclear Engineering and Technology, 2020, 52 (6), 1213-1221. DOI: 10.1016/j.net.2019.11.019.
10. Leontyeva-Smirnova, M.V., Izmalkov, I.N., Valitov, I.R., Loshmanov, L.P., Kostyukhina, A.V., and Fedotov, P.V. Determination of the yield strength of EK–181 steel during tensile tests of ring specimens. Zavodskaya Laboratoriya. Diagnostika Materialov, 2016, 82 (10), 56–61. (In Russian).
11. Karagergi, R.P., Evseev, M.V., and Kozlov, A.V. Distribution of plastic deformation along the perimeter of circular specimen of thin-wall fuel-element cladding during its expansion. Materials Physics and Mechanics, 2021, 47 (1), 74–88. DOI: 10.18149/MPM.4712021_8.
12. Martin-Rengel, M.A., Gómez Sánchez, F.J., Ruiz-Hervías, J., and Caballero, L. Determination of the hoop fracture properties of unirradiated hydrogen-charged nuclear fuel cladding from ring compression tests. Journal of Nuclear Materials, 2013, 436 (1–3), 123–129. DOI: 10.1016/j.jnucmat.2013.01.311.
13. Herb, J., Sievers, J., and Sonnenburg, H.-G. A new cladding embrittlement criterion derived from ring compression tests. Nuclear Engineering and Design, 2014, 273, 615–630. DOI: 10.1016/j.nucengdes.2014.03.047.
14. Desquines, J. and Guilbert, S. Effect of an oxide layer on the result of a ring compression test on a fuel cladding sample after a simulated LOCA transient. In: Top Fuel, Prague, Czech Republic, October 1–4 2018: proceedings of conference. Available at: https://www.researchgate.net/publication/328496506_EFFECT_OF_AN_OXIDE_LAYER_ON_THE_RESULT_OF_A_RING_COMPRESSION_TEST_ON_A_FUEL_CLADDING_SAMPLE_AFTER_A_SIMULATED_LOCA_TRANSIENT
15. Frolov, A.S., Fedotov, I.V., and Gurovich, B.A. Evaluation of the true-strength characteristics for isotropic materials using ring tensile test. Nuclear Engineering and Technology, 2021, 53 (7), 2323–2333. DOI: 10.1016/j.net.2021.01.033.
16. Karagergi, R.P., Konovalov, A.V., Evseev, M.V., and Kozlov, A.V. Construction of a strain-hardening diagram to analyze the state of stress in the fuel-element cladding material. Russian Metallurgy (Metally), 2023, 2023, 1528–1534. DOI: 10.1134/S0036029523100117.
17. Karagergi, R.P., Kozlov, A.V., Yarkov, V.Yu., Pastukhov, V.I., Barsanova, S.V., Churyumova, T.A., Mitrofanova, N.M., and Leontyeva-Smirnova, M.V. Microstructure of fracture surfaces after radial compression of annular specimens made of cladding austenitic steel exposed to damaging dose above 100 dpa. Physics of Metals and Metallography, 2024, 125 (6), 665–672. DOI: 10.1134/S0031918X2460043X.
18. Konovalov, A.V. and Partin, A.S. RF Software Registration Certificate No. 2023660789, 2020. (In Russian).

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