Determination of thorium fission rate based on 135I in thorium oxide cylinder bombarded by D-T fusion neutrons. (September 2018)

• Record Type: Journal Article
• Authors: Zheng, Lei; Yang, Yiwei; Liu, Rong; Liu, Zhujun; Wang, Mei; Jiang, Li; Wen, Zhongwei; Wang, Kan; Liu, Xingyan
• Is Part Of: Annals of nuclear energy. Volume 119(2018)
• Page Start: 264
• Page End: 270
• Publication Date: 2018-09
• Subjects: Thorium fission rate -- 135I -- Activation method -- MCNP simulation -- D-T fusion neutrons -- Thorium oxide cylinder; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2018.05.012
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: Generalized self-absorption coefficient was defined and calculated in detail. The newly measured thorium fission products yields was adopted. Three kinds of metal monitors were used to monitor the neutron flux. The activation method by observing 135 I was introduced in detail. Abstract: Aiming at developing the activation method and provide reference for the validation of thorium fission parameters, a dedicated integral experiment was carried out in a thorium oxide cylinder bombard by D-T fusion neutrons. Thorium fission rate in the axial direction of the cylinder was determined by detecting the 1260.409 keV gamma emitted from fission product 135 I, with experimental uncertainties of 6.2%. MCNP calculations employing ENDF/B-VII.0, ENDF/B-VII.1, JENDL-4.0, CENDL-3.1 library data were in good agreement with measured thorium fission rates within experimental uncertainties. The agreement of measured reaction rates of monitors with the calculations on the whole demonstrated the reliability of this experiment in some degree, and could provide reference for the analyses of thorium fission rates. Neutron spectra and the contribution of neutrons in each sub-energy range to thorium fission rate were also analyzed. The activation method to determine thorium fission rate was developed and the data obtained in this work could provide reference for the validation of thorium fission parameters.