Chu Thoi Nam, Le Tran Quang Linh, Donny Hartanto, Tran Hoai Nam, Nguyen Kien Cuong, Vu Thanh Mai

Main Article Content

Abstract

This paper presents the analysis of sensitivity and uncertainty for the infinite multiplication factor (kinf) for the VVR-M2 typed HEU and LEU fuel assemblies of the Dalat nuclear research reactor (DNRR) using the MCNP6.1-Whisper1.1 code. Sensitivity calculations were performed for the ENDF/B-VII.0 and ENDF/B-VII.1 nuclear data libraries. In Whisper, the keff uncertainty due to nuclear data was evaluated by the uncertainty propagation law using the sensitivities obtained by MCNP and the available covariance matrix. The most significant sensitivity coefficients in positive contribution are the coefficient total n and fission reaction of U-235, elastic scattering reaction of H-1 and inelastic scattering of thermal neutrons and in negative contribution are capture reactions of U-235, H-1, Al-27, U-238 and U-234 isotopes. The large discrepancy between sensitivities of elastic scattering reaction cross section of H-1 and inelastic scattering of thermal neutrons between two libraries are found because of the change in neutron spectra of HEU and LEU fuel assemblies using the two library versions. The uncertainty of the kinf from the ENDF/B-VII.0 nuclear library error for all isotopes was found to be significant (about 0.45% of reactivity effect) with the largest contribution from isotope U-235 contributions (about 0.3% to 0.40%).


 

Keywords: Sensitivity, Uncertainty, DNRR, MCNP6.1- Whisper-1.1, ENDF/B-VII.0, ENDF/B-VII.1

References

[1] N. D. Nguyen, (Ed.), Safety Analysis Report for the Dalat Nuclear Research Reactor, Nuclear Research Institute, Vietnam Atomic Energy Commission, 2009.
[2] Q. B. Do, G. T. T. Phan, K. C. Nguyen, Q. H. Ngo, H. N. Tran, Criticality And Rod Worth Analysis Of The DNRR Research Reactor Using The SRAC and MCNP5 Codes, Nuclear Engineering and Design., Vol. 343, 2019,
pp. 197-209, https://doi.org/10.1016/j.nucengdes.2019.01.011.
[3] MCNP Development Team, MCNP6.2 User’s manual Code Version 6.2, LA-UR-17-29981, 2017.
[4] M. B. Chadwick, P. Oblozinsky, M. Herman et al., ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology, Nuclear Data Sheets, Vol. 107, 2006, pp. 2931-3060, https://doi.org/10.1016/j.nds.2006.11.001.
[5] M. B. Chadwick, M. Herman et al., ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data, Nuclear Data Sheets, Vol. 112, 2011, pp. 2887–2996, https://doi.org/10.1016/j.nds.2011.11.002.
[6] F. B. Brown, M. E. Rising, J. L. Alwin, User Manual for Whisper-1.1, Los Alamos National Laboratory, LA-UR-17-20453, 2017.
[7] A. A. Enin, A. N. Erykalov, G. A. Kirsanov, K. A. Konoplev, V. S. L’vov, Y. V. Petrov, Y. P. Saikov,
A. S. Zakharov, V. S. Zvezdkin, Design and Experience of HEU and LEU Fuel for WWR-M Reactors, Nuclear Engineering and Design, Vol. 182, 1998, pp. 233-240.
[8] T. Goorley, M. James, T. Booth, F. Brown, J. Bull, L. J. Cox, J. Durkee, J. Elson, M. Fensin, R. A. Forster,
J. Hendricks, H.G. Hughes, R. Johns, B. Kiedrowski, R. Martz, S. Mashnik, G. McKinney, D. Pelowitz, R. Prael, J. Sweezy, L. Waters, T. Wilcox, Features of MCNP6, Annals of Nuclear Energy, Vol. 87, No. 2, 2016,
pp. 772-783, https://doi.org/10.1016/j.anucene.2015.02.020.
[9] B. C. Kiedrowski, F. B. Brown et al., Whisper: Sensitivity/Uncertainty-Based Computational Methods and Software for Determining Baseline Upper Subcritical Limits, Nuclear Science Engineering, Vol. 181, No.1, 2015, https://doi.org/10.13182/NSE14-99.
[1] N. D. Nguyen, (Ed.), Safety Analysis Report for the Dalat Nuclear Research Reactor, Nuclear Research Institute, Vietnam Atomic Energy Commission, 2009.
[2] Q. B. Do, G. T. T. Phan, K. C. Nguyen, Q. H. Ngo, H. N. Tran, Criticality And Rod Worth Analysis Of The DNRR Research Reactor Using The SRAC and MCNP5 Codes, Nuclear Engineering and Design., Vol. 343, 2019,
pp. 197-209, https://doi.org/10.1016/j.nucengdes.2019.01.011.
[3] MCNP Development Team, MCNP6.2 User’s manual Code Version 6.2, LA-UR-17-29981, 2017.
[4] M. B. Chadwick, P. Oblozinsky, M. Herman et al., ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology, Nuclear Data Sheets, Vol. 107, 2006, pp. 2931-3060, https://doi.org/10.1016/j.nds.2006.11.001.
[5] M. B. Chadwick, M. Herman et al., ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data, Nuclear Data Sheets, Vol. 112, 2011, pp. 2887–2996, https://doi.org/10.1016/j.nds.2011.11.002.
[6] F. B. Brown, M. E. Rising, J. L. Alwin, User Manual for Whisper-1.1, Los Alamos National Laboratory, LA-UR-17-20453, 2017.
[7] A. A. Enin, A. N. Erykalov, G. A. Kirsanov, K. A. Konoplev, V. S. L’vov, Y. V. Petrov, Y. P. Saikov,
A. S. Zakharov, V. S. Zvezdkin, Design and Experience of HEU and LEU Fuel for WWR-M Reactors, Nuclear Engineering and Design, Vol. 182, 1998, pp. 233-240.
[8] T. Goorley, M. James, T. Booth, F. Brown, J. Bull, L. J. Cox, J. Durkee, J. Elson, M. Fensin, R. A. Forster,
J. Hendricks, H.G. Hughes, R. Johns, B. Kiedrowski, R. Martz, S. Mashnik, G. McKinney, D. Pelowitz, R. Prael, J. Sweezy, L. Waters, T. Wilcox, Features of MCNP6, Annals of Nuclear Energy, Vol. 87, No. 2, 2016,
pp. 772-783, https://doi.org/10.1016/j.anucene.2015.02.020.
[9] B. C. Kiedrowski, F. B. Brown et al., Whisper: Sensitivity/Uncertainty-Based Computational Methods and Software for Determining Baseline Upper Subcritical Limits, Nuclear Science Engineering, Vol. 181, No.1, 2015, https://doi.org/10.13182/NSE14-99.