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Solving point burnup equations by Magnus method

  • Cai, Yun (Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China) ;
  • Peng, Xingjie (Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China) ;
  • Li, Qing (Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China) ;
  • Du, Lin (Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China) ;
  • Yang, Lingfang (Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China)
  • Received : 2018.11.24
  • Accepted : 2019.01.10
  • Published : 2019.05.25

Abstract

The burnup equation of nuclides is one of the most equations in nuclear reactor physics, which is generally coupled with transport calculations. The burnup equation describes the variation of the nuclides with time. Because of its very stiffness and the need for large time step, this equation is solved by special methods, for example transmutation trajectory analysis (TTA) or the matrix exponential methods where the matrix exponential is approximated by CRAM. However, TTA or CRAM functions well when the flux is constant. In this work, a new method is proposed when the flux changes. It's an improved method compared to TTA or CRAM. Furtherly, this new method is based on TTA or CRAM, and it is more accurate than them. The accuracy and efficiency of this method are investigated. Several cases are used and the results show the accuracy and efficiency of this method are great.

Keywords

References

  1. H.A. Ashi, L.J. Cummings, P.C. Matthews, Comparison of methods for evaluating functions of a matrix exponential, Appl. Numer. Math. 59 (2009) 468-486. https://doi.org/10.1016/j.apnum.2008.03.039
  2. H. Bateman, The solution of a system of differential equations occurring in the theory of radioactive transformations, Proc. Camb. Phil. Soc. 15 (1910) 423-427.
  3. A.G. Croff, A User's Manual for the ORIGEN2 Computer Code, Oak Ridge National Laboratory, 1980. ORNL/TM-7175.
  4. A. Yamamoto, M. Tatsumi, N. Sugimura, et al., Numerical solution of stiff burnup equation with short half lived nuclides by the Krylov subspace method, J. Nucl. Sci. Technol. 44 (2) (2007) 147-154. https://doi.org/10.1080/18811248.2007.9711268
  5. M. Pusa, Rational approximations to the matrix exponential in burnup calculations, Nucl. Sci. Eng. 169 (2) (2011) 155-167. https://doi.org/10.13182/NSE10-81
  6. D. She, K. Wang, G.L. Yu, Development of the point-depletion code DEPTH, Nucl. Eng. Des. 258 (2013a) 235-240. https://doi.org/10.1016/j.nucengdes.2013.01.007
  7. S. Blanes, et al., The Magnus expansion and some of its applications, Phys. Rep. 470 (2009) 151-238. https://doi.org/10.1016/j.physrep.2008.11.001
  8. F. Casas, A. Iserles, Explicit Magnus expansions for nonlinear equations, J. Phys. Math. Gen. 39 (2006) 5445-5461. https://doi.org/10.1088/0305-4470/39/19/S07
  9. D. She, A. Zhu, K. Wang, Using generalized Laguerre polynomials to compute the matrix exponential in burnup equations, Nucl. Sci. Eng. 175 (3) (2013b) 259-265. https://doi.org/10.13182/NSE12-48
  10. Y. Kawamoto, G. Chiba, M. Tsuji, et al., Numerical solution of matrix exponential in burn-up equation using mini-max polynomial approximation, Ann. Nucl. Energy 80 (2015) 219-224. https://doi.org/10.1016/j.anucene.2015.02.015
  11. A.E. Isotalo, P.A. Aarnio, Comparison of depletion algorithms for large systems of nuclides, Ann. Nucl. Energy 38 (2) (2011) 261-268. https://doi.org/10.1016/j.anucene.2010.10.019
  12. S. Blanes, P.C. Moan, Fourth- and sixth-order commutator-free Magnus integrators for linear and non-linear dynamical systems, Appl. Numer. Math. 56 (2006) 1519-1537. https://doi.org/10.1016/j.apnum.2005.11.004