Determination of the 232Th(n,2n)231Th reaction rate in thorium oxide cylinder assembly under D-T neutron source

  • Jie Wen
  • Yiwei Yang
  • Rong Liu
  • Zhujun Liu
  • Mei Wang
  • Zhongwei Wen


Aiming at verifying the evaluated cross-section of 232Th(n,2n) reaction for the conceptual design of thorium based subcritical blanket in fusion–fission hybrid reactor, an integral experiment was carried out using activation technique with D-T neutrons. 232Th(n,2n) reaction rates were measured in a ThO2 cylinder assembly with relative uncertainty of 8.0%. The experiment was simulated by MCNP code combining with ENDF/B-VII.0, ENDF/B-VII.1, CENDL-3.1 and JENDL-4.0 databases. The calculated 232Th(n,2n) reaction rates employing JENDL-4.0 show low discrepancy with the measured ones. The results could provide reference to the re-evaluation of 232Th(n,2n) cross-section and the design of fusion–fission hybrid reactor.


232Th(n,2n) reaction rate D-T neutron source Fusion–fission hybrid reactor MCNP 



This work was funded by the National Nature Science Foundation of China (11505164) and the Neutron Physics Key Laboratory Foundation (2015BC02), thanks will be given to the Accelerator Department of INPC for their great work in D-T neutron source operation.


  1. 1.
    Liu C (1989) A brief introduction to the fusion-fission hybrid reactor physics. Nucl Tech 12(8–9):561–564 Chinese Google Scholar
  2. 2.
    Shi X, Peng X (2010) Preliminary concept design on blanket neutronics of a fusion–fission hybrid reactor for energy production. Nucl Power Eng 31(4):5–7 Chinese Google Scholar
  3. 3.
    Wols FJ, Kloosterman JL et al (2015) Conceptual design of a passively safe thorium breeder pebble bed reactor. Ann Nucl Energy 75:542–558CrossRefGoogle Scholar
  4. 4.
    Tewes HA, Caretto AA, Miller AE et al (1960) Excitation functions of neutron-induced reactions. Nuclear and Radiation Chemical Symposium, Chalk RiverGoogle Scholar
  5. 5.
    Perkin JL, Coleman RF (1961) Cross-sections for the (n,2n) reactions of 232Th, 238U and 237Np with 14 MeV neutrons. J Nucl Energy 14(1–4):69–75Google Scholar
  6. 6.
    Karius H, Ackermann A, Scobel W (1979) The pre-equilibrium contribution to the (n,2n) reactions of 232Th and 238U. J Phys G 5(5):715CrossRefGoogle Scholar
  7. 7.
    Reyhancan IA (2011) Measurements and model calculations of activation cross sections for 232Th(n,2n)231Th reaction between 13.57 and 14.83 MeV neutrons. Ann Nucl Energy 38(11):2359–2362CrossRefGoogle Scholar
  8. 8.
    Chadwick MB, Obložinsky P, Herman M, Greene NM, Mcknight RD, Smith DL et al (2006) ENDF/B-VII.0: next generation evaluated nuclear data library for nuclear science and technology. Nucl Data Sheets 107(12):2931–3060CrossRefGoogle Scholar
  9. 9.
    Chadwick MB, Herman M, Obložinsky P, Dunn ME, Danon Y, Kahler AC et al (2011) ENDF/B-VII.1 nuclear data for science and technology: cross sections, covariances, fission product yields and decay data. Nucl Data Sheets 112(12):2887–2996CrossRefGoogle Scholar
  10. 10.
    Ge ZG, Zhao ZX, Xia HH et al (2011) The updated version of Chinese evaluated nuclear data library (CENDL-3.1). J Korean Phys Soc 59(2):1052–1056CrossRefGoogle Scholar
  11. 11.
    Shibata Keiichi, Iwamoto Osamu, Nakagawa Tsuneo, Nobuyuki IWAMOTO, Ichihara Akira, Kunieda Satoshi et al (2011) JENDL-4.0: a new library for nuclear science and engineering. J Nucl Sci Technol 48(1):1–30CrossRefGoogle Scholar
  12. 12.
    Zagryadskii VA, Markovskii DV, Novikov VM, Chuvilin DY, Shatalov GE (1989) Calculated neutron transport verifications by integral 14 MeV-neutron source experiments with multiplying assemblies. Fusion Eng Des 9(3):347–352CrossRefGoogle Scholar
  13. 13.
    Adam J, Bhatia C, Katovsky K, Kumar V (2011) A study of reaction rates of (n, f), (n, γ) and (n,2n) reactions in natU and 232Th by the neutron fluence produced in the graphite set-up (gamma-3) irradiated by 2.33 GeV deuteron beam. Eur Phys J A 47(7):1–18CrossRefGoogle Scholar
  14. 14.
    Liu Z, Yang C, Yang Y et al (2018) Measurement and analysis of 232Th(n,2n)231Th reaction rate in the thorium oxide cylinder with D-T neutron source. Ann Nucl Energy 111:660–665CrossRefGoogle Scholar
  15. 15.
    Yang Y, Liu R et al (2013) Thorium capture ratio determination through γ-ray off-line method. Acta Phys Sin 62(3):032801 Chinese Google Scholar
  16. 16.
    Briesmeister JF (2000) MCNPTM-A general Monte Carlo Nparticle transport code. Version 4C, LA-13709-M. Los Alamos (NM): Los Alamos National LaboratoryGoogle Scholar
  17. 17.
    Yan X, Liu R, Lu X et al (2012) Measurement and analysis of the 238U(n,2n) reaction rate in depleted uranium/polyethylene shells. Chin Phys C 36(7):670–674CrossRefGoogle Scholar
  18. 18.
    Yan X, Liu R, Lu X et al (2012) Measurement and analysis of neutron capture rate of U-238 in an alternate depleted uranium/polyethylene system. Acta Phys Sin 61(10):102801 Chinese Google Scholar
  19. 19.
    Yang Y, Yan X, Liu R et al (2012) Determination of the 238U capture to total fission ratio in alternate depleted uranium/polyethylene shells with D-T neutrons. Fusion Eng Des 87(9):1679–1683CrossRefGoogle Scholar
  20. 20.
    ENDF/B-VI Decay Data.
  21. 21.
    Standard Test Methods for Detector Calibration and Analysis of Radionuclides. AstmGoogle Scholar
  22. 22.
    M. Drosg (2003) DROSG-2000, codes and database for 59 neutron source reactions, documented in the IAEA report IAEA-NDS-87 Rev, received from the IAEA Nuclear Data SectionGoogle Scholar

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© Akadémiai Kiadó, Budapest, Hungary 2018

Authors and Affiliations

  1. 1.College of Nuclear Science and EngineeringSichuan UniversityChengduChina
  2. 2.Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyangChina

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