TY - JOUR
T1 - Coupling of system thermal-hydraulics and Monte-Carlo code
T2 - Convergence criteria and quantification of correlation between statistical uncertainty and coupled error
AU - Wu, Xu
AU - Kozlowski, Tomasz
PY - 2015/1
Y1 - 2015/1
N2 - Coupled multi-physics approach plays an important role in improving computational accuracy. Compared with deterministic neutronics codes, Monte Carlo codes have the advantage of a higher resolution level. In the present paper, a three-dimensional continuous-energy Monte Carlo reactor physics burnup calculation code, Serpent, is coupled with a thermal-hydraulics safety analysis code, RELAP5. The coupled Serpent/RELAP5 code capability is demonstrated by the improved axial power distribution of UO2and MOX single assembly models, based on the OECD-NEA/NRC PWR MOX/UO2Core Transient Benchmark. Comparisons of calculation results using the coupled code with those from the deterministic methods, specifically heterogeneous multi-group transport code DeCART, show that the coupling produces more precise results. A new convergence criterion for the coupled simulation is developed based on the statistical uncertainty in power distribution in the Monte Carlo code, rather than ad-hoc criteria used in previous research. The new convergence criterion is shown to be more rigorous, equally convenient to use but requiring a few more coupling steps to converge. Finally, the influence of Monte Carlo statistical uncertainty on the coupled error of power and thermal-hydraulics parameters is quantified. The results are presented such that they can be used to find the statistical uncertainty to use in Monte Carlo in order to achieve a desired precision in coupled simulation.
AB - Coupled multi-physics approach plays an important role in improving computational accuracy. Compared with deterministic neutronics codes, Monte Carlo codes have the advantage of a higher resolution level. In the present paper, a three-dimensional continuous-energy Monte Carlo reactor physics burnup calculation code, Serpent, is coupled with a thermal-hydraulics safety analysis code, RELAP5. The coupled Serpent/RELAP5 code capability is demonstrated by the improved axial power distribution of UO2and MOX single assembly models, based on the OECD-NEA/NRC PWR MOX/UO2Core Transient Benchmark. Comparisons of calculation results using the coupled code with those from the deterministic methods, specifically heterogeneous multi-group transport code DeCART, show that the coupling produces more precise results. A new convergence criterion for the coupled simulation is developed based on the statistical uncertainty in power distribution in the Monte Carlo code, rather than ad-hoc criteria used in previous research. The new convergence criterion is shown to be more rigorous, equally convenient to use but requiring a few more coupling steps to converge. Finally, the influence of Monte Carlo statistical uncertainty on the coupled error of power and thermal-hydraulics parameters is quantified. The results are presented such that they can be used to find the statistical uncertainty to use in Monte Carlo in order to achieve a desired precision in coupled simulation.
KW - Carlo
KW - Coupled simulation
KW - Monte
KW - System thermal-hydraulics
KW - Uncertainty quantification
UR - http://www.scopus.com/inward/record.url?scp=84907197788&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84907197788&partnerID=8YFLogxK
U2 - 10.1016/j.anucene.2014.08.016
DO - 10.1016/j.anucene.2014.08.016
M3 - Article
AN - SCOPUS:84907197788
SN - 0306-4549
VL - 75
SP - 377
EP - 387
JO - Annals of Nuclear Energy
JF - Annals of Nuclear Energy
ER -