Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
권호 표지
DOI QR코드

DOI QR Code

A Study on the Optimal Position for the Secondary Neutron Source in Pressurized Water Reactors

  • Sun, Jungwon (KEPCO Nuclear Fuel) ;
  • Yahya, Mohd-Syukri (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Kim, Yonghee (Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST))
  • Received : 2015.12.23
  • Accepted : 2016.05.08
  • Published : 2016.12.25
Download PDF
⟨ Previous Next ⟩

Abstract

This paper presents a new and efficient scheme to determine the optimal neutron source position in a model near-equilibrium pressurized water reactor, which is based on the OPR1000 Hanul Unit 3 Cycle 7 configuration. The proposed scheme particularly assigns importance of source positions according to the local adjoint flux distribution. In this research, detailed pin-by-pin reactor adjoint fluxes are determined by using the Monte Carlo KENO-VI code from solutions of the reactor homogeneous critical adjoint transport equations. The adjoint fluxes at each allowable source position are subsequently ranked to yield four candidate positions with the four highest adjoint fluxes. The study next simulates ex-core detector responses using the Monte Carlo MAVRIC code by assuming a neutron source is installed in one of the four candidate positions. The calculation is repeated for all positions. These detector responses are later converted into an inverse count rate ratio curve for each candidate source position. The study confirms that the optimal source position is the one with very high adjoint fluxes and detector responses, which is interestingly the original source position in the OPR1000 core, as it yields an inverse count rate ratio curve closest to the traditional 1/M line. The current work also clearly demonstrates that the proposed adjoint flux-based approach can be used to efficiently determine the optimal geometry for a neutron source and a detector in a modern pressurized water reactor core.

Keywords

References

  1. Nuclear Power Generation Department, Safety Evaluation for a Startup Operation without Neutron Source of Kori Unit 1, Korea Electric Power Company, LTD, 1998.
  2. J.S. Chung, I.T. Woo, The Nuclear Design Report for Ulchin Nuclear Power Plant Unit 3 Cycle 7, Korea Nuclear Fuel Company, 2005. KNF-U3C7-05026 Rev.0.
  3. W. Bojduj, Source Range Detector Response during Boron Dilution Accident at Shutdown, American Nuclear Society: 2010 Annual Meeting, San Diego (CA), 2010, pp. 517-518.
  4. Y.A. Chao, H.Q. Lam, J.D. Gibbons, M.D. Heibel, M. Kauchi, The Spatially Corrected Inverse Count Rate (SCICR) Method for Subcritical Reactivity Measurement, American Nuclear Society: 2004 Annual Meeting, Washington, D.C., 2004, pp. 728-730.
  5. C.A. Ford, Modeling a Source Range Channel Response during a PWR Core Onload Sequence, American Nuclear Society: 2010 Annual Meeting, San Diego (CA), 2010, pp. 639-641.
  6. United States Nuclear Regulatory Commission, Information Notice No. 93-32: Non-conservative Inputs for Boron Dilution Event Analysis, IN-93-32, 1993.
  7. United States Nuclear Regulatory Commission, Generic Letter No. 85-05: Inadvertent Boron Dilution Events, GL-85-05, 1985.
  8. S. Goluoglu, L.M. Petrie Jr., M.E. Dunn, D.F. Hollenbach, B.T. Rearden, Monte Carlo criticality methods and analysis capabilities in SCALE, Nucl. Technol. 174 (2010) 214-235.
  9. S.M. Bowman, SCALE 6: comprehensive nuclear safety analysis code system, Nucl. Technol. 174 (2010) 126-148.
  10. D.E. Peplow, Monte Carlo shielding analysis capabilities with MAVRIC, Nucl. Technol. 174 (2010) 289-313.
  11. H. Nifenecker, S. David, J.M. Loiseaux, O. Meplan, Basics of accelerator driven subcritical reactors, Nucl. Instr. Meth. Phys. Res. A 463 (2001) 428-467. https://doi.org/10.1016/S0168-9002(01)00160-7
  12. P. Seltborg, Source efficiency and high-energy neutronics in accelerator-driven systems, Ph.D. Thesis, Department of Nuclear and Reactor Physics Royal Institute of Technology Stockholm, Sweden, 2005.
  13. G.I. Bell, S. Glasstone, Nuclear Reactor Theory, Van Nostrand Reinhold Company, New York, 1970.
  14. K.O. Ott, R.J. Neuhold, Nuclear Reactor Dynamics, American Nuclear Society, Le Grange Park (IL), 1985.
  15. Y. Kim, W.S. Park, C.K. Park, Characterization of a source importance function in an accelerator-driven system, Nucl. Sci. Eng. 144 (2003) 227-241. https://doi.org/10.13182/NSE03-A2356
  16. J.G. Ahn, N.Z. Cho, J.E. Kuh, Generation of spatial weighting functions for ex-core detectors by adjoint transport calculation, Nucl. Technol. 103 (1993) 114-121. https://doi.org/10.13182/NT93-A34834
  17. Scale: A Comprehensive Modeling and Simulation Suite for Nuclear Safety Analysis and Design, 2011. ORNL/TM-2005/39, Version 6.1. Available from Radiation Safety Information Computational Center at Oak Ridge National Laboratory as CCC-785.
  18. S.M. Bowman, O.W. Hermann, M.C. Brady, SCALE-4 Analysis of Pressurized Water Reactor Critical, Oak Ridge National Laboratory, Oak Ridge (TN), ORNL/TM-12294/V2, 1995.

Cited by

  1. Secondary-Source Core Reload Modeling with VERA vol.195, pp.3, 2016, https://doi.org/10.1080/00295639.2020.1820797
  2. Benchmark on neutron flux spatial effects in subcritical system based on IRT-4 M fuel for near-core positions vol.157, pp.None, 2016, https://doi.org/10.1016/j.anucene.2021.108231