A Simulation of Rod Ejection Accident in an Advanced Small PWR Core without Soluble Boron

The soluble boron is used to control the long-term excess reactivity in commercial PWRs but the use of soluble boron has disadvantages such as complications of the reactor coolant system and generation of the liquid wastes. Therefore, there have been lots of interests in designing PWR reactor without soluble boron. Recently, we have designed new small 50 MWe PWR core having no soluble boron for long-term reactivity control. In the core, the excess reactivity is controlled by using the control rods and the advanced particle type burnable poisons over the cycle. The one of the most important issues for the boron-free core is to check if the core is safe under the rod ejection accidents because the reactor is operated with insertion of the control rods. The objective of this work is to give the detailed analysis results of the rod ejection accidents for the advanced small PWR core were analyzed. (authors)