Monte Carlo burn up codes are powerful and accurate tools but they are also quite demanding on calculation time because the reaction rates required for burn up calculations are always calculated within a Monte Carlo code. By studying the Monte Carlo simulation process and the calculation of reaction rates by Monte Carlo in particular, we have identified a more efficient approach to reaction rate calculation with Monte Carlo. This allows us to reduce a single burn up step to a single spectral Monte Carlo calculation without reaction rates which decreases the calculation time significantly (a factor 33 decrease for a fuel pin model has been observed). We have implemented this approach into ALEPH, a Monte Carlo burn up code using MCNP or MCNPX, ORIGEN and NJOY. We have benchmarked ALEPH on the NEA-OECD BUC IV-B benchmark and on the ARIANE experimental data in the framework of the VALMOX project. It has also been shown that a statistical error of around 0.5 % on the total flux in a cell is sufficient to obtain reliable results on the isotope composition.
|Title of host publication||ALEPH - A Monte Carlo Burn Up Code|
|Place of Publication||Brussels, Belgium|
|State||Published - 21 Aug 2005|
|Event||ICENES 2005 - 12th International Conferences on Emerging Nuclear Energy Systems - SCK.CEN, Brussels|
Duration: 22 Aug 2005 → 26 Aug 2005
|Conference||ICENES 2005 - 12th International Conferences on Emerging Nuclear Energy Systems|
|Period||2005-08-22 → 2005-08-26|