Boron Dilution Transients

Emergency cooling water injection could lead to boron dilution transients in the reactor core resulting in reactivity insertions. The analysis of such transients involves complex mixing processes in the cold legs, the downcomers and finally in the reactor core of light water reactors. In order to demonstrate the safe operation of a nuclear power plant with respect to boron dilution transients, detailed CFD analyses are required in combination with established quality guidelines.

In cooperation with a utility, new experimental reference data has been generated using the ROCOM facility for two reference boron dilution transients. NRG’s CFD methodology was benchmarked and validated against the state-of-the-art experimental data obtained and quality guidelines were set up. Reactor scale simulations were subsequently performed in order to demonstrate safe plant operation.