Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
권호 표지
DOI QR코드

DOI QR Code

The first application of modified neutron source multiplication method in subcriticality monitoring based on Monte Carlo

  • Received : 2019.01.24
  • Accepted : 2019.08.18
  • Published : 2020.03.25
Download PDF
⟨ Previous Next ⟩

Abstract

The control rod drive mechanism needs to be debugged after reactor fresh fuel loading. It is of great importance to monitor the subcriticality of this process accurately. A modified method was applied to the subcriticality monitoring process, in which only a single control rod cluster was fully withdrawn from the core. In order to correct the error in the results obtained by Neutron Source Multiplication Method, which is based on one point reactor model, Monte Carlo neutron transport code was employed to calculate the fission neutron distribution, the iterated fission probability and the neutron flux in the neutron detector. This article analyzed the effect of a coarse mesh and a fine mesh to tally fission neutron distributions, the iterated fission probability distributions and to calculate correction factors. The subcriticality before and after modification is compared with the subcriticality calculated by MCNP code. The modified results turn out to be closer to calculation. It's feasible to implement the modified NSM method in large local reactivity addition process using Monte Carlo code based on 3D model.

Keywords

References

  1. Masashi Tsuji, Nobuhide Suzuki, Yoichiro Shimazu, Subcriticality measurement by neutron source multiplication method with a fundamental mode extraction[J], J. Nucl. Sci. Technol. 40 (3) (2003) 158-169. https://doi.org/10.1080/18811248.2003.9715346
  2. Win Naing, Masashi Tsuji, Yoichiro Shimazu, The effect of neutron source distribution on subcriticality measurement of pressurized water reactors using the modified neutron source multiplication method[J], J. Nucl. Sci. Technol. 40 (11) (2003) 951-958. https://doi.org/10.1080/18811248.2003.9715438
  3. Guillaume Truchet,W.F.G. van Rooijen, Y. Shimazu, K. Yamaguchi, Application of the modified neutron source multiplication method to the prototype FBR Monju[J], Ann. Nucl. Energy 51 (2013) 94-106. https://doi.org/10.1016/j.anucene.2012.07.040
  4. L.N. Ussachoff, Equation for the importance of neutrons, reactor kinetics and the theory of perturbations[C], Proc. Int. Conf. on the Peaceful Uses of Atomic Energy, Geneva, Switzerland 8-21 (1955) 503-510. Aug.
  5. G.I. Bell, S. Glasstone, Nuclear Reactor Theory, VanNostrand Reinhold, 1970, p. 252. Chap. IV.
  6. Yasushi Nauchi, Takanori Kameyama, Development of calculation technique for iterated fission probability and reactor kinetic parameters using continuousenergy Monte Carlo method[J], J. Nucl. Sci. Technol. 47 (11) (2010) 977-990. https://doi.org/10.1080/18811248.2010.9711662
  7. X-5 Monte Carlo Team, MCNP-A General Monte Carlo N-Particle Transport Code[R], Version 5, LA-UR-03-1987, Los Alamos National Laboratory (LANL), 2003.
  8. ISO/IEC GUIDE 98-3, Uncertainty of Measurement - Part 3: Guide to the Expression of Uncertainty in Measurements (GUM), 2008.
  9. ISO/IEC GUIDE 98-3, Uncertainty of Measurement - Part 3: Guide to the Expression of Uncertainty in Measurements (GUM)) Supplement 1: Propagation of Distributions Using a Monte Carlo Methode, 2008.