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Sensitivity of a control rod worth estimate to neutron detector position by time-dependent Monte Carlo simulations of the rod drop experiment

  • Jong Min Park (Nuclear Engineering Department, Seoul National University) ;
  • Cheol Ho Pyeon (Institute for Integrated Radiation and Nuclear Science, Kyoto University) ;
  • Hyung Jin Shim (Nuclear Engineering Department, Seoul National University)
  • Received : 2023.06.30
  • Accepted : 2023.11.06
  • Published : 2024.03.25

Abstract

The control rod worth sensitivity to the neutron detector position in the rod drop experiment is studied by the time-dependent Monte Carlo (TDMC) neutron transport calculations for AGN-201K educational reactor and the Kyoto University Critical Assembly. The TDMC simulations of the rod drop experiments are conducted by the Seoul National University Monte Carlo (MC) code, McCARD, yielding time-dependent neutron densities at detector positions. The detector-position-dependent results of the total control rod worth calculated by the extrapolation, the integral counting, and the inverse methods are compared with the numerical reference using the MC eigenvalue calculations and the experimental results. From these comparisons, it is observed that the total control rod worth can be estimated with a considerable difference depending on the detector position through the rod drop experiment. The proposed TDMC simulation of the rod drop experiment can be applied for searching a better detector position or quantifying a bias for the control rod worth measurement.

Keywords

Acknowledgement

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No.2022M2D2A1A02063865).

References

  1. T. Misawa, H. Unesaki, C.H. Pyeon, Nuclear Reactor Physics Experiments, Kyoto University Press, Kyoto, 2010. 
  2. J.J. Duderstadt, L.J. Hamilton, Nuclear Reactor Analysis, Wiley, New York, 1976. 
  3. K. Hashimoto, T. Ohsawa, R. Miki, T. Shibata, Derivation of consistent reactivity worth and eigenvalue separation from space-dependent rod worths on the basis of modal approach, Ann. Nucl. Energy 18 (6) (1991) 317-325.  https://doi.org/10.1016/0306-4549(91)90017-R
  4. O. Novak, L. Sklenka, F. Fejt, I. Maldonado, O. Chvala, Rod drop transient at VR-1 reactor-Experiment and Serpent transient calculation analysis, Ann. Nucl. Energy 141 (2020), 107296. 
  5. T. Sano, K. Hashimoto, H. Taninaka, U. Hironobu, Significant spatial dependence observed in inverse kinetics analysis for a loosely coupled-core system of the Kyoto University Critical Assembly, J. Nucl. Sci. Technol. 55 (11) (2018) 1355-1361.  https://doi.org/10.1080/00223131.2018.1509027
  6. M.H. Kim. Research & Educational Reactor AGN-201K, Reactor Research & Education Center, Kyung Hee University, 2018. https://scholar.google.com/scholar?hl=ko&as_sdt=0%2C5&q=M.H.+Kim%2C+Research+%26+Educational+Reactor+AGN-201K%2C+Reactor+Research+%26+Education+Center%2C+Kyung+Hee+University%2C+2018&btnG=. 
  7. S.H. Jang, H.J. Shim, Advances for the time-dependent Monte Carlo neutron transport analysis in McCARD, Nucl. Eng. Technol. 55 (2023) 2712-2722. 
  8. H.J. Shim, B.S. Han, J.S. Jung, H.J. Park, C.H. Kim, McCARD: Monte Carlo code for advanced reactor design and analysis, Nucl. Eng. Technol. 44 (2012) 161-176.  https://doi.org/10.5516/NET.01.2012.503
  9. K.S. Song, H.J. Shim, M.H. Kim, McCARD Analysis for AGN-201K Reactor Physics Experiments, Korea Nuclear Society, Yeosu, Republic of Korea, 2018. October 25-26. 
  10. D. Bowen, Space-time Kinetics of the AGN-201M Research Reactor at the University of New Mexico, PhD Dissertation, The University of New Mexico, 2015. 
  11. C.H. Pyeon, K. Morioka, Monte Carlo analyses of light-water-moderated and light-water-reflected cores with highly-enriched uranium fuel at Kyoto University Critical Assembly, J. Nucl. Sci. Technol. 59 (2022) 257-265.  https://doi.org/10.1080/00223131.2021.1961636
  12. T.F. Coleman, Y. Li, An interior trust region approach for nonlinear minimization subject to bounds, SIAM J. Optim. 6 (1996) 418-445. https://doi.org/10.1137/0806023