Modeling of the Gamma Radiolysis Process in Light and Heavy Water Nuclear Reactors

Document Type : Research Paper

Authors

1 Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran

Abstract

In water-cooled and moderated reactors, radiolysis is the source of hydrogen, deuterium, and oxygen production, as well as hydrogen peroxide (deuterium peroxide). Modeling the radiolysis phenomenon from a safety perspective is crucial for predicting the production of corrosive or explosive compounds. In this study, a gamma radiolysis model was developed for light and heavy water, and ode15s was selected as the appropriate solver for the model. The validation results of the developed model indicate an error of less than 5%. The absorbed dose effect in the range of 0.5 to 100 Gy/s, temperature in the range of 20 to 70 °C, and the effect of initial hydrogen (deuterium) concentration in the range of zero to 50 ppb were investigated for both light and heavy water. The results showed that gamma radiolysis has more obvious effects on light water compared to heavy water, and the rate of change in the concentration of oxidizing compounds, oxygen, and hydrogen (deuterium) peroxide, is lower than the rate of change in hydrogen (deuterium) concentration. The maximum difference between the final concentration of hydrogen and deuterium occurs at an absorptive dose of 100 Gy/s, where the produced hydrogen concentration is 3.5 times higher than the produced deuterium concentration from radiolysis. As the temperature increases from 20 to 70 °C, the stable concentration of radiolysis-produced compounds decreases by a maximum of 70% for hydrogen and 50% for deuterium. Increasing the initial concentration of hydrogen (deuterium) always reduces the concentration of oxidizing species (oxygen, hydrogen (deuterium) peroxide). However, the graph of produced hydrogen (deuterium) exhibits an optimal threshold (20 ppb for hydrogen and 10 ppb for deuterium). Therefore, by controlling the absorptive dose, temperature, and initial hydrogen concentration to the optimum values, corrosion resulting from the production of oxidizing agents and hydrogen (deuterium) explosions can be prevented.

Keywords

Main Subjects

References

[1]. Dzaugis, M. E., Spivack, A. J., & D'Hondt, S. (2015). A quantitative model of water radiolysis and chemical production rates near radionuclide-containing solids. Radiation Physics and Chemistry, 115, 127-134, doi.org/10.1016/j.radphyschem.2015.06.011.##
[2]. Ramshesh, V. (2001). Safety aspect concerning radiolytic gas generation in reactors. Science Progress, 84(1), 69-85, doi.org/10.3184/0036850017832390. ##
[3]. Ramshesh, V., & Venkateswarlu, K. S. (1988). Radiolytic generation of gases in reactors (No. BARC--1438). Bhabha Atomic Research Centre. ##
[4]. Vereshchinskii, I.V. & A.K. Pikaev (1964) Introduction to radiation chemistry, 1st edittion, Israel Program for Scientific Translations, published in Holly Tel Aviv-Yafo University, 1-578. ##
[5]. Elliot, A. J., & Bartels, D. M. (2009). The reaction set, rate constants and g-values for the simulation of the radiolysis of light water over the range 20 deg to 350 deg C based on information available in 2008 (No. AECL--153-127160-450-001). Atomic Energy of Canada Limited. ##
[6]. Elliot, A. J., Ouellette, D. C., & Stuart, C. R. (1996). The temperature dependence of the rate constants and yields for the simulation of the radiolysis of heavy water. ##
[7]. Ershov, B. G., & Gordeev, A. V. (2008). A model for radiolysis of water and aqueous solutions of H2, H2O2 and O2. Radiation Physics and Chemistry, 77(8), 928-935, doi.org/10.1016/j.radphyschem.2007.12.005. ##
[8]. Hochanadel, C. J. (1952). Effects of cobalt γ-radiation on water and aqueous solutions. The Journal of Physical Chemistry, 56(5), 587-594, doi.org/10.1021/j150497a008. ##
[9]. Swiatla-Wojcik, D. (2016). Hybrid method for numerical modelling of LWR coolant chemistry, Radiation Physics and Chemistry, 127, 236-242, doi.org/10.1016/j.radphyschem.2016.07.005. ##
[10]. Swiatla-Wojcik, D. (2022). A numerical simulation of radiation chemistry for controlling the oxidising environment in water-cooled nuclear power reactors, Applied Sciences, 12(3), 947, doi.org/10.3390/app12030947. ##
[11]. Yakabuskie, P. A., Joseph, J. M., Stuart, C. R., & Wren, J. C. (2011). Long-term γ-radiolysis kinetics of NO3− and NO2− solutions, The Journal of Physical Chemistry A, 115(17), 4270-4278, doi.org/10.1021/jp200262c. ##
[12]. Yakabuskie, P. A., Joseph, J. M., & Wren, J. C. (2010). The effect of interfacial mass transfer on steady-state water radiolysis, Radiation Physics and Chemistry, 79(7), 777-785, doi.org/10.1016/j.radphyschem.2010.02.001. ##
[13]. Markad, U. S., Lisouskaya, A., & Bartels, D. M. (2023). Reactions of Nickel Ions in Water Radiolysis up to 300° C, The Journal of Physical Chemistry B, 127(12), 2784-2791, doi.org/10.1021/acs.jpcb.3c00046 . ##
[14]. Shadman, M. M., Ghazanfari, V., Amini, Y., Mansourzadeh, F., & Taheri, A. (2023). Modeling and simulation of the radiolytic deuterium and oxygen generation in heavy water reactors, Nuclear Engineering and Design, 413, 112514, doi.org/10.1016/j.nucengdes.2023.112514. ##
[15]. JohnáElliot, A. (1993). Temperature dependence of g values for H 2 O and D 2 O irradiated with low linear energy transfer radiation. Journal of the Chemical Society, Faraday Transactions, 89(8), 1193-1197, doi.org/10.1039/FT9938901193. ##
[16]. Gear, C. W. (1971). Numerical initial value problems in ordinary differential equations, Prentice-Hall series in automatic computation. ##
[17]. Huang, X., Wang, S., Tai, M., Zhang, L., & Li, Y. (2017). Solution and computer simulation of complex linear reaction kinetics, Chemical Engineering Transactions, 59, 583-588, doi.org/10.3303/CET1759098. ##
[18]. Shampine, L. F., & Gear, C. W. (1979). A user’s view of solving stiff ordinary differential equations, SIAM Review, 21(1), 1-17, doi.org/10.1137/102100. ##
[19]. Manichev, V., Zhuk, D., & Feldman, E. (2019). The basic set of test problems for ODE system solvers. In IOP Conference Series: Materials Science and Engineering, 630(1), 012012, IOP Publishing. ##
Journal of Petroleum Research
Volume 33, Issue 133 - Serial Number 133
January and February 2024
Pages 24-38

Files

Share

How to cite

Statistics