Abstracts and Available Papers Presented at the 2002 International RERTR Meeting
COMPARISONS OF
DIFFUSION THEORY AND MONTE CARLO BURNUP
N. A. Hanan, R. B. Pond, M. M.
Bretscher, and J. E. Matos
RERTR Program
Technology Development Division
Argonne National
Laboratory
Argonne, Illinois
60439-4841 USA
ABSTRACT
Burnup
analyses for research reactors have mostly been performed using diffusion
theory codes. Lately, with the increase
in computing power, the Monte Carlo method is being used more frequently. The Monte Carlo method provides a more
precise way to perform burnup analyses for nuclear reactors. However, the method is very computer and
time intensive. The purpose of this
paper is to show that burnup analyses using diffusion theory with appropriate cross
sections can provide results for different reactors, fuel enrichments, and fuel
assembly types that are essentially the same as the Monte Carlo results.
This
paper compares the results of diffusion theory and Monte Carlo burnup analyses
for four different reactors (HFR-Petten in the Netherlands, WWR-SM in
Uzbekistan, WWR-M in Ukraine, and TRR-II in Taiwan); different types of fuel
assemblies (MTR, IRT-3M, IRT-MR, WWR-M2, and WWR-MR) were studied for these
reactors. The performance parameters selected for these comparisons were: a)
K-effective during the cycle; b) power produced in the fuel assemblies; and c)
burnup-dependent isotopic compositions of the different fuel assemblies (235U,
238U, 135Xe, and 239Pu). The results show that for all parameters
considered both the diffusion theory and the Monte Carlo burnup yield essentially
identical results.