Bereznev V.P., Belov A.A., Koltashev D.A.
Nuclear Safety Institute of the Russian Academy of Sciences, Moscow, Russia
The research is devoted to the features of radiation shieldind calculations by the deterministic program ODETTA, which is intended for numerical simulation of the neutron and photon transport in shielding compositions of the nuclear facilities and based on the discrete ordinates method and finite element method on unstructured tetrahedral meshes.
The article describes the methods of the uncollided radiation component calculations implemented in the ODETTA program for “ray” effect elimination which is typical for discrete ordinates method in weakly scattering media with localized radiation sources. In addition, the first collision method allows to correctly simulating point sources, and the last collision method allows calculating the required functionals at the detection points located outside the computational domain. The implemented methods have been tested on computational benchmarks and experiments, a brief description of which is given in the article.
The results obtained were compared with analytical and experimental data, as well as with the results of calculations by the Monte Carlo method within the Scale 6.2.3 software package. The analysis of the influence of the calculated parameters is carried out and conclusions are drawn about the effectiveness of the implemented methods.
1. Longoni G., Haghighat A. Development and Application of the Regional Angular Refinement Technique and its Application to Non-conventional Problems. Proc. of the PHYSOR. Seoul, 2002.
2. Bin Zhang, Liang Zhang, Cong Liu, Yixue Chen. Goal-Oriented Regional Angular Adaptive Algorithm for the SN Equations. Nuclear Science and Engineering, 2018, no. 189:2, pp. 120–134.
3. Wareing T., Morel J., Parsons D. A first collision source method for ATTILA, an unstructured tetrahedral mesh discrete ordinates code. Proc. Topical Conf.: Technologies for the New Century. Nashville, TN, ANS, LaGrange, IL, USA, 1998.
4. Ragusa J.C., Dehart M.D. Uncollided Flux Techniques for Discrete-Ordinate Radiation Transport Solutions in Rattlesnake. Idaho, Idaho National Laboratory, 2016.
5. Hanuš M., Harbour L.H., Ragusa J.C., Adams M.P., Adams M.L. Uncollided flux techniques for arbitrary finite element meshes. Journal of Computational Physics, 2019, vol. 398, pp. 108848. https://doi.org/10.1016/j.jcp.2019.07.046.
6. Belousov V.I., Grushin N.A., Sychugova E.P., Seleznev E.F. Nekotorye rezul'taty verifi-katsii koda ODETTA dlya neodnorodnykh zadach [Some results of verification of the ODETTA code for inhomogeneous problems]. Voprosy atomnoy nauki i tekhniki. Seriya: Fizika yadernykh reaktorov – Problems of Atomic Science and Technology. Seria: Physics of Nuclear Reactors, 2018, no. 3, pp. 46–53.
7. CONSYST-RF. Certificate of state registration of the computer program, no. 2016612865 to 11.03.2016.
8. Koshcheev V.N., Manturov G.N., Nikolaev M.N. et al. Biblioteka gruppovykh konstant BNAB-RF dlya raschetov reaktorov i zashchity [Library of group constants ABNAB-RF for calculations of reactors and protection]. Izvestiya VUZov. Yadernaya Energetika – Proceedings of Universities. Nuclear Energy, 2014, no. 3, pp. 93–101.
9. Hermanns M. Parallel Programming in Fortran 95 using OpenMP. Spain, School of Aeronautical Engineering, 2002.
10. The HDF Group. Available at: https://www.hdfgroup.org/solutions/hdf5/ (accessed 19.01.2021).
11. Ribes A., Caremoli C. Salomé platform component model for numerical simulation, COMPSAC 07. Proc. 31st Annual International Computer Software and Applications Conference. Washington, DC, USA, 2007, pp. 553–564.
12. Childs H., Brugger E., Whitlock B. et al. VisIt: An End-User Tool for Visualizing and Analyzing Very Large Data. In a book: “High Performance Visualization – Enabling Extreme-Scale Scientific Insight”. Chapman and Hall/CRC Publ., 2012, pp. 357–372. https://doi.org/10.1201/b12985 .
13. Kim J.W., Lee Y.-O. AETIUS solutions for Kobayashi 3D benchmarks with the first collision source method on the volume source and unstructured tetrahedral mesh. Ann. Nucl. Energy, 2018, vol. 11, pp. 446–469.
14. Kobayashi K., Sugimura N., Nagaya Y. 3D radiation transport benchmark problems and results for simple geometries with void region. Prog. Nucl. Energy, 2001, no. 39 (2), pp. 119–144.
15. Ueki K., Ohashi A. Neutron Shielding Ability of KRAFTON N2 – Mannan – KRAFTON N2 Sandwich-Type Material and Others. Proc. of New Horizons in Radiation Protection and Shielding Topical Meeting. Pasco, WA, 1992.
16. Rearden B.T., Jessee M.A. SCALE Code System, ORNL/TM-2005/39, Version 6.2.3. Oak Ridge, Oak Ridge National Laboratory, 2018.
17. American National Standard, Neutron and Gamma-Ray Flux-to-Dose Rate Factors. ANSI/ANS-6.1.1-1977.