Development of boron tracking and boron hideout (CRUD) model based on subchannel approach

The results illustrated that CRUD layer contains small amount of boron, which can delay boron dilution in specific transient. Although the effect is quite small, according to the parameter study in Section 3.1, this phenomenon may be considerable in severe accidents. Moreover, boron dilution transient is simulated in a 3 × 3 rod bundle and a widely used 17 × 17 assembly. The results show that the boron dilution speed is positively correlated with channel's hydraulic diameter.