# Current Physical Problems of the Dynamic Damage in Elements of the First Circuit of VVER Reactors

І. G. Sharaevsky, Т. S. Vlasenko, L. B. Zimin,
А. V. Nоsоvskyi, N. М. Fіаlkо, G. І. Sharaevsky

Institute for Safety Problems of Nuclear Power Plants,
NAS of Ukraine, 12, Lysogirska st., Kyiv, 03028, Ukraine

DOI: doi.org/10.31717/2311-8253.22.2.1

### Abstract

In the context of the actual problems of the physics of operational damage of modern reactor steels produced in the leading countries of the world (USA, Russia, Western Europe) and used for the manufacture of nuclear reactor vessels and other equipment of the first circuit of nuclear power plants, the characteristic features of possible dynamic damage in the responsible elements of this are considered. The mentioned problems are systematized from the standpoint of analyzing the effects of radiation embrittlement, as well as physical and chemical processes that, under certain conditions, are capable of developing in the operating equipment of Ukrainian NPPs, which are already working out their design operational resource. The characteristic features of possible dynamic damage in the operating reactor equipment of Ukrainian and foreign nuclear power plants are considered. The problem is systematized, first of all, from the standpoint of analyzing the operational stability of domestic and foreign reactor steels in relation to their radiation embrittlement. The peculiarities of the course of this physical process have been analyzed, which should be taken into account when determining the maximum possible terms of extension of safe operation of nuclear power units with reactors of the VVER type at the NPP of Ukraine. The main metal-physical properties of reactor steels of various types and possible problems caused by neutron irradiation, physical and chemical processes, vibrational and thermomechanical fatigue, which threaten the unexpected sudden destruction of reactor vessels, are considered. Special attention is paid to mechanical damage and processes accompanying the operation of reactor housings under conditions of cyclic and dynamic loads. A warning has been given regarding the unjustified extension of the period of reactors safe operation. The significant technological lag of the former Soviet, and now Russian, metallurgy from the level of metallurgy of the leading Western countries was noted. Data are provided on the high operational properties of the latest American steels, from which modern reactors of the AR1000 type are manufactured in the USA, and the safety, technical, economic and environmental advantages of using these reactors in Ukraine in comparison with new models of reactors of the VVER-1000 and VVER-1200.

Keywords: reactor vessel, reactor steel, thermomechanical and radiation embrittlement, service life, term of safe operation.

References

1. Energy strategy of Ukraine for the period up to 2035 “Security, energy efficiency, competitiveness”. Approved by the Order of the Cabinet of Ministers dated 18.08.2017 no. 605-p, 66 p. Available at: http://mpe.kmu.gov.ua/minugol/doccatalog/document?id=245229554. (in Ukr.)

2. Nechaeva Т. P. (2018). [Estimation of expediency of perspective nuclear reactors introduction taking into account requirements to reliability and ecological functioning of UES of Ukraine]. The Problems of General Energy, vol. 52, no. 1, pp. 42–48. (in Ukr.)

3. Karas’ V. I., Komarov A. O., Papkovich V. G., Pilipenko N. N., Shilyаev B. A. (2010). Nanoscopic processes radiation embrittlement pressure vessel steels. Problems of Atomic Science and Technology, no. 3, pp. 194–199. (in Rus.)

4. Gurovich B. A., Shtrombakch Ya. I., Kuleshova E. A., Fedotova S. V. (2010). Structural criteria of recovery annealing regime selection for VVER-1000 reactor pressure vessel materials. Problems of Atomic Science and Technology, no. 5, pp. 50–57. (in Rus.)

5. Моrozov А. М., Nikolaev V. А., Yurchenko Е. V., Vasil’ev V. G. (2000). [Influence of nickel on radiation embrittlement of base metal and weld metal of steel 15Kh2NMFA-A]. Proceedings of the VI Int. conf. “Problems of materials science in the design, manufacture and operation of nuclear power plant equipment” (Saint Petersburg, June 19–23, 2000). Saint Petersburg: Prometei, vol. 2, pp. 372–396. (in Rus.)

6. Каrzov G. P., Nikolaev V. А., Filimonov Т. N. (2006). [Development and improvement of radiation-resistant steels for vessels of pressurized water reactors]. Voprosy ma‑ terialovedeniya [Materials science issues], vol. 45, no. 1, pp. 111–123. (in Rus.)

7. Kasatkin О. G. (2009). Thermal embrittlement of welded joints of bodies of WWER type reactors. Problems of Atomic Science and Technology, vol. 94, no. 4–2, pp. 232–235. (in Rus.)

8. Nazarchuk Z. T., Neklyudov I. M., Skalskyi V. R. (2016). Меtod аkustychnoyi emisii v diagnostuvanni korpusiv reaktoriv atomnykh elektrostancij [The method of acoustic emission in the diagnosis of NPP reactor vessels]. National Academy of Sciences of Ukraine, NSC “Kharkiv Physical and Technical Institute”, G. V. Karpenko Physical-Mechanical Institute. Kyiv: Naukova Dumka, 306 p. (in Ukr.)

9. The number of nuclear power units to be built in Ukraine using Westinghouse technology has increased to 9. Government portal. Available at: https://www.kmu.gov.ua/news/kilkist-atomnih-energoblokiv-shcho-pobuduyut-vukrayini-za-tehnologiyami-westinghouse-zbilshilas-do-9.

10. Krasovskyi А. Ya. (1980). Khrupkost’ metallov pri nyzrikh temperaturakh [Brittleness of metals at low temperatures]. Kyiv: Naukova Dumka, 340 p. (in Rus.)

11. Kliuchnikov A. A., Sharaevsky I. G., Fialko N. M., Zimin L. B., Sharaevskaya E. I. (2012). Teplofizika avarii yadernykh reaktorov [Thermal physics of NPP accidents]. Chornobyl: ISP NPP, NAS of Ukraine, 528 p. (in Rus.)

12. Kliuchnikov А. А., Sharaevsky I. G., Fialko N. M., Zimin L. B., Sharaevskaya N. I. (2013). Teplofizika povrezhdenij reaktornykh ustanovok [Thermophysics of NPP damages]. Kyiv: ISP NPP, NAS of Ukraine, 528 p. (in Rus.)

13. Shah V. N., MacDonald P. E. (1993). Aging and life extension of major light water reactor components. New York: Elsevier Science & Technology, 943 p.

14. Grinik E. U., Chirko L. I., et al. (2000). [Radiation embrittlement of vessel steels of the VVER-1000 reactor]. Problems of Atomic Science and Technology, vol. 4, pp. 57–60. (in Rus.)

15. Grinik E. U., Revko V. N., Chirko L. I., Chaikovsky Yu. V. (2007). Evaluation of fracture toughness of the VVER-1000 reactor vessel materials. Nuclear Physics and Atomic Energy, vol. 8, no. 19, pp. 83–88. (in Rus.)

16. USSR State Committee for the Supervision of Safe Work in the Nuclear Power Industry (1989). PNAE G-7–002–86. Norms for calculating the strength of equipment and pipelines of nuclear power plants. Moscow: Energoatomizdat, 525 p. (in Rus.)

17. Lambrigger M. (1999). Weibull master curves and fracture toughness testing. Part III Master curves for the evaluation of dynamic Charpy impact tests. J. Mater. Sci, vol. 34, pp. 4447–4455.

18. Khmara D. О. (2010). [Public remarks on the continuation of operation of Ukrainian NPP power units beyond the project deadline]. Nuclear and Radiation Safety, vol. 1, pp. 43–47. (in Ukr.)

19. Proskuriakov K. N. (2006). [Thermal-hydraulic reasons for the growth of dynamic stresses and cracks in the lids of vessel reactors]. Teploenergetika [Thermal power engineering], vol. 9, pp. 22–25. (in Rus.)

20. Sharevsky І. G. (2010) Rozpiznavannia peredavarijnykh teplogydravlichykh procesiv u vodookholodzhuvanykh jadernykh energenychnykh reactorakh [Recognition of pre-emergency thermohydraulic processes in watercooled nuclear power reactors] (PhD thesis). Кyiv: ISP NPP, NAS of Ukraine, 48 р. (in Ukr.)

21. Karzov G. P. (2011). [Materials science aspects of new principles for improving the performance of heat-resistant steels for npp cases and their practical implementation]. Problems of Atomic Science and Technology, vol. 2, pp. 46–53. (in Rus.)

22. Monakhov A. S. (1986). Atomnyye elektricheskiye stantsii i ikh tekhnologicheskoye oborudovaniye [Nuclear power stations and their technological equipment]. Moscow: Energoatomizdat, 224 p. (in Rus.)

23. Timofeev B. Т., Zotova А. О. (2006). [Radiation resistant]. Atomic strategy, vol. 24, no. 4, pp. 28–29. (in Rus.)

24. Natesan K., Majumdar S., Shankar P. S., Shah V. N. (2006). Preliminary materials selection issues for the next generation nuclear power plants pressure vessel. Report ANL/EXT-06–45. Argonne: Argonne National Laboratory, 109 p.

25. IAEA (2009). Integrity of reactor pressure vessels in nuclear power plants assessment of irradiation embrittlement effects and reactor pressure vessel steels. IAEA Nuclear Energy Series no. NP-T-3.11. Vienna: IAEA, 156 p.

Full Text (PDF)

Published
2022-12-21

If the article is accepted for publication in the journal «Industrial Heat Engineering» the author must sign an agreement on transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a  Creative Commons Attribution License International CC-BY that allows others to share the work with an acknowledgement of the work’s authorship and initial publication in this journal.

Insert math as
$${}$$