Radiation Physics and Engineering
A peer-reviewed journal published by K. N. Toosi University of Technology

Second order average current nodal expansion method for time-dependent neutron diffusion simulation

Document Type : Research Article

Authors

Kambiz Valavi
Ali Pazirandeh
Gholamreza Jahanfarnia

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

https://doi.org/10.22034/rpe.2021.300458.1037
Abstract
In the present work, a time-dependent neutron diffusion simulator is developed utilizing the second order of average current nodal expansion method. Generally, nodal methods can accurately simulate the reactor core with coarse meshes as long as the sizes of a fuel assembly. In this case, an adopted iterative approach is used for resolving the time-dependent three-dimensional multi-group neutron balance equations coupled with six-group precursor equations. In order to evaluate the implemented methodology, two popular transient problems are used including TWIGL two-dimensional seed-blanket reactor and three-dimensional LMW LWR. For indicating the precision of the method, the numerical results of high (second) order approach also have been compared with the basic methodology i.e. the zeroth order solution. From the comparison of obtained results with references, the suitable and precise simulating of transient schemes can be comprehended using the time-dependent second order average current nodal expansion method. Moreover, the results confirm that the second order solution can treat the coarse mesh dynamic problems with more accuracy relative to the basic approach.

Highlights

• Investigation of second order of average current nodal expansion method.
• Comparing zeroth and second order solution results.
• Perform static and dynamic calculation for each test case and compare the results with reference.

Keywords

Second order of average current nodal expansion method
Neutron diffusion equation
Transient treatment
Precursor equations
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Radiation Physics and Engineering
Volume 2, Issue 3
Summer 2021
Pages 9-15

  • Receive Date 19 August 2021
  • Revise Date 21 September 2021
  • Accept Date 07 October 2021

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