Nuclear Techniques ›› 2018, Vol. 41 ›› Issue (9): 90602-090602.doi: 10.11889/j.0253-3219.2018.hjs.41.090602

• NUCLEAR ENERGY SCIENCE AND ENGINEERING • Previous Articles     Next Articles

The effects of the shape function and weighting function on the kinetics of the ADS sub-critical reactor

HOU Cheng1, YU Tao1,2, XIE Jinsen1,2, ZENG Wenjie1,2, CHEN Zhenping1,2, XIE Qin1,2, LIU Zijing1,2, ZHAO Pengcheng1,2, HE Lihua1,2   

  1. 1 School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;
    2 Virtual Simulation Experimental Teaching Center on Nuclear Energy and Technology, University of South China, Hengyang 421001, China
  • Received:2018-04-04 Revised:2018-05-28 Online:2018-09-10 Published:2018-09-12
  • Supported by:
    Supported by National Natural Science Foundation of China (No.11575079)

Abstract: [Background] According to the quasi-static method, the kinetic parameters can be calculated by the convolution of the weighting function, kinetic operators and the shape function. The traditional shape function and weighting function are not suitable for kinetic analysis of source driven sub-critical system.[Purpose] In order to improve the calculation accuracy and understand physical characteristics of the source driven sub-critical system better, different shape functions and weighting functions were applied to improved quasi-static method, and they were evaluated respectively.[Methods] Individually, the λ regular flux, α regular flux and the steady flux of source driven sub-critical system are adopted as the initial shape functions. The λ-eigenequation and α-eigenequation of the critical weighting function of kinetic parameter model, and the global weighting function of kinetic parameter model are used for the weighting function. Then the kinetic parameters and the neutron kinetic results of the starting progress and beam loss conditions can be calculated in the sub-critical system.[Results] The results of the IQS method are compared with the results obtained directly from the spatio-temporal dynamics equation. We can find that the weighting function is the dominant factor that affect the kinetic parameters and the kinetic results. And during the starting progress, the steady flux of source driven sub-critical system and the λ-eigenequation of the critical weighting function model have obvious superiority in describing the kinetic characters of the source driven sub-critical system; for the beam loss conditions, adopting the global weighting function model to calculate the weighting function is suitable for the sub-critical system.[Conclusion] The phenomenon that the change of weighting function falls behind the transition of the external neutron source indicates that the extraneous neutron source's effect on neutron importance is inhomogeneous and the inhomogeneous character should be taken into consideration when optimizing the weighting function models.

Key words: Neutron kinetics, ADS sub-critical reactor, Weighting function, IQS method

CLC Number: 

  • TL327