Pressurized nuclear plant 10B abundance evolution study

•The evolution equation of 10B abundance is deduced and verified by measurement.•The equation is simplified by Taylor expansion without losing accuracy.•The deviation between theoretical and measured boron concentration is well fixed.•Useful measured data of 10B abundance in some major systems is listed in detail.

The boron concentration deviation between measurement and prediction in Pressurized Water Reactor (PWR) is mainly caused by the decrease of 10B abundance. The evolution equation of 10B abundance during the cycle is deduced according to theoretical calculation and also verified by measurement at different burn-up. The deviation between theoretical and measured boron concentration that frequently happened at long-cycle fuel reload management can be fixed with the equation.