On the use of predictor–corrector method for coupled Monte Carlo burnup codes

• Numerical stability and accuracy of Monte-Carlo (MC) burnup coupling schemes was investigated.
• Conventional coupling methods can be numerically unstable and the problem is common to all MC-depletion codes.
• Two modified PC coupling approaches are suggested.
• The methods maintain the accuracy, while consume considerably less computational time.

This paper investigates the effect of the burnup coupling scheme on the numerical stability and accuracy of coupled Monte-Carlo depletion calculations. We show that in some cases, even the Predictor Corrector method with relatively short time steps can be numerically unstable. In addition, we present two possible extensions to the Euler predictor–corrector (PC) method, which is typically used in coupled burnup calculations. These modifications allow using longer time steps, while maintaining numerical stability and accuracy.