INFLUENCE OF PROTECTIVE COATINGS ON HAFNIUM HYDRIDE ON ITS THERMAL DECOMPOSITION

This work studies hafnium hydride as an absorber for fast neutron reactors. A high value of the neutron absorption cross section was noted which remains the same for all hafnium isotopes formed during neutron irradiation in the reactor. However, there is a risk of hafnium hydride decomposition in the range of 600–700°C which corresponds to the operating temperature of absorbers in fast neutron reactors. An approach has been proposed to reduce the release of hydrogen from hafnium hydride which consists of applying a protective coating of hafnium oxide to it. Hafnium hydride samples were annealed to temperatures of 1200°C in a simultaneous thermal analysis unit in helium. The beginning of hydrogen desorption corresponds to a temperature of 640°C. Complete release of hydrogen was shown at a temperature of 1200°C. Significant reduction in hydrogen desorption at low temperatures was shown when annealing samples with coatings,. A special installation has been developed that allows thermal testing of hydride materials in a liquid sodium environment. Hafnium hydride was annealed in liquid sodium at 700°C. Synchronous thermal analysis of samples after exposure to sodium showed a decrease in gas desorption which is associated with an increase in the thickness of the oxide layer on the surface of the samples.

1. Waltar A.E., Reynolds A.B. Fast Breeder Reactors. 1981. New York: Pergamon Press.

2. Iwasaki T., Konashi K. // J. Nucl. Sci. Technol. 2009. V. 46 (8). P. 874. https://doi.org/10.1080/18811248.2007.9711595

3. Ikeda K., Moriwaki H., Ohkubo Y., et al. // Nucl. Eng. Des.. 2014. V. 278. P. 97. https://doi.org/10.1016/j.nucengdes.2014.07.002

4. Рисованный В.Д., Захаров А.В., Клочков Е.П. // Известия вузов: Ядерная энергетика. 2011. №1. С. 240.

5. Dolukhanyan S.K., Alexanian A.G., Hakobian A.G. // Int. J. Hydrogen Energy. 1995. V. 20 (5). P. 391.

6. Polunin K.K., Mokrushin A.A., Bragin S.Yu., et al. // J. Phys.: Conf. Ser. 2020. V. 1683. P. 032042. https://doi.org/10.1088/1742-6596/1683/3/032042

7. Пирожков А.В., Курдюмов Н., Эльман Р.Р. // Тр. XIX Междунар. конф. “Перспективы развития фундаментальной науки”. 2022. T. 1. C. 161.

8. Tachibana T., Koura H., Katakura J. // Japan Nuclear Data Center. 2010. Ibaraki: JAEA. https://wwwndc.jaea.go.jp/jendl/jendl.html

9. Guo H., Buiron L., Kooyman T., Sciora P. // Ann. Nucl. Energy. 2019. V. 132. P. 713.

10. Konashi K., Itoh K., Kido T. et al. // Proc. ICAPP'13. Apr. 14−18, 2013. Jeju Island, Rep. Korea. 2014. Red Hook, NY: Curran Associates Inc. FF232.

11. Suzuki A., Yagi J., Konashi K. // Proc. ICAPP'13 , Apr. 14− 18, 2013. Jeju Island, Rep. Korea. 2014. Red Hook, NY: Curran Associates Inc. FF229.

12. Siegel S., Carter R.L., Bowman B.E. et al. // Proc. UN Int. Conf. Peaceful Uses of Atomic Energy. Aug. 8–20, 1955. Geneva, Switzerland. 1955. V. 9. P. 321–330.

13. Samotaev N., Litvinov A., Oblov K., et al. // Sensors. 2023. V. 23. P. 514.

14. Bolodurin B., Korchak V., Litvinov A., et al. // Russ. J. Gen. Chem. 2018. V. 88 (12). P. 2732.

15. Etrekova M., Litvinov A., Samotaev N. et al. // Springer Proceedings in Physics. Proc. Int. Youth Conf. Electronics, Telecommunications and Information Technologies. Velichko E., Vinnichenko M., Kapralova V., Koucheryavy Y. (Eds.). 2020. Cham: Springer. P. 87. https://doi.org/10.1007/978-3-030-58868-7_10

16. Спивак Л.В., Щепина Н.Е. // Альтернативная энергетика и экология. 2015. V. 21 (185). P. 84.