An international journal published by K. N. Toosi University of Technology

Document Type : Research Article


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

2 Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran


The neutronic safety parameters determine reactor dynamic response. These parameters change as a function of core inventory during reactor cycle. Therefore, assessment of reactor behavior throughout operational cycle is an important issue in reactor safety analysis for transients. The purpose of the present study is to evaluate SMART reactor response to changes in neutronic safety parameters during reactor cycle in reactivity insertion accident condition. MCNPX 2.6 nuclear code is utilized to calculate neutronic safety parameters throughout reactor cycle. The reactor dynamic model is simulated based on point kinetic equations and lumped temperatures to predict reactor response to ramp reactivity insertion. Based on this approach, the effect of neutronic parameters on reactor behavior are investigated in the beginning and end of cycle under reactivity transients. Hot full and zero power operational reactor states are considered in the analysis. Results illustrate that reactor at end of cycle has faster response with smaller transient power peak during reactivity insertion accident compared to beginning of cycle. The neutronic parameters, specifically negative feedbacks at both beginning and end of reactor cycle guarantee the safe performance of reactor at all examined conditions. The detailed comparative results are explained in the paper.


• Variation of neutronic safety parameters versus reactor cycle time is evaluated.
• Reactor behavior is analyzed under ramp reactivity insertion accident.
• Reactor dynamic response is predicted based on point kinetic equations and lumped temperature model.


Akbari, M., Rezaei, S., and Khoshahval, F. (2018). Kinetic parameters calculation during first cycle of the WWER-1000 reactor core. CNL Nuclear Review, 8(1):63–70.
CNSC (2003). Science and Reactor Fundamentals – Reactor Physics. Canadian Nuclear Safety Commission.
Farkas, G., Mich´alek, S., and Haˇscık, J. (2008). MCNP5 delayed neutron fraction (βeff) calculation in training reactor VR–1. Journal of Electrical Engineering, 59(4):221–224.
Hunt, B. R., Lipsman, R. L., and Rosenberg, J. M. (2014). A guide to MATLAB: for beginners and experienced users. Cambridge university press.
Ingersoll, D. T. and Carelli, M. D. (2015). Handbook of small modular nuclear reactors. Woodhead Publishing.
Kamalpour, S., Salehi, A. A., Khalafi, H., et al. (2018). The potential impact of Fully Ceramic Microencapsulated (FCM) fuel on thermal hydraulic performance of SMART reactor. Nuclear Engineering and Design, 339:39–52.
Kamalpour, S., Salehi, A. A., Khalafi, H., et al. (2019). Impact of integral burnable absorbers on SMART reactor behavior under normal and anomalous operational conditions. Progress in Nuclear Energy, 110:51–63.
Lee, W. (2010). The SMART reactor. 4th Annual Asian-Pacific Nuclear Energy Forum. Louis, H. K. (2021a). Assessment of neutronic safety parameters of VVER-1000 core under accident conditions. Progress in Nuclear Energy, 132:103609.
Louis, H. K. (2021b). Sensitivity analysis of the kinetic parameters to physical parameters variation in VVER reactor. Nuclear and Particle Physics, 11:15–26.
MacFarlane, R. and Muir, D. (1994). The NJOY Nuclear Data Processing System. Los Alamos National Laboratory LA-12740-M.
Pelowitz, D. (2008). MCNPX User’s Manual. Technical report, LA-CP-07-1473 Version 2.6. 0. Los Alamos, NM: US Department of Energy.
Pinem, S., Sembiring, T. M., Sunaryo, G. R., et al. (2018). Reactivity coefficient calculation for AP1000 reactor using the NODAL3 code. In Journal of Physics: Conference Series, volume 962, page 012057. IOP Publishing.
Reda, S. M., Gomaa, I. M., Bashter, I. I., et al. (2021). Neutronic performance of the VVER-1000 Reactor Using Thorium Fuel with ENDF Library. Science and Technology of Nuclear Installations, 2021.
Shusterman, J. (2021). Fissile and fertile fuels, Volume 1. Encyclopedia of Nuclear Energy.
Stankovskiy, A. and Van den Eynde, G. (2012). Advanced method for calculations of core burn-up, activation of structural materials, and spallation products accumulation in accelerator-driven systems. Science and Technology of Nuclear Installations, 2012.
Torabi, M., Lashkari, A., Masoudi, S. F., et al. (2018). Neutronic analysis of control rod effect on safety parameters in Tehran Research Reactor. Nuclear Engineering and Technology, 50(7):1017–1023.
Van Dam, H., Van der Hagen, T., and Hoogenboom, J. (2005). Nuclear reactor physics. Delft University of Technology, Department of Nuclear Engineering.