Measurement of safely injection fluid transport in a scaled reactor test

An existing geometric and fluid-fluid scaled facility is applied to investi gate the transport of berated safety injection (SI) fluid in the Westinghou se AP600 reactor vessel during a main steam-line rupture (MSLR) event. The AP600 reactor has coaxial injection into the vessel downcomer rather than t he cold-leg cross-flow injection typical of operating power reactors. This gas-flow test facility has unique derail in the representation of the SI no zzle-to-core inlet path most important to SI transport. Analysis of the tra nsport phenomena expected in the reactor and the scaled facility, given MSL R conditions, indicates that both buoyancy and turbulent diffusion can have comparable influences on SI transport. It is shown that different reactor- to-experiment velocity ratios are required to scale each phenomenon. Tests are performed to evaluate transient SI fluid concentration at the core inle t using the appropriate velocity ratios to scale buoyancy and diffusion. Tw o asymmetric loop-flow boundary conditions representative of the MSLR event as well as a symmetric flow condition are applied While no one test result is fully similar to the expected reactor transport, this ensemble of rests provides data that are valuable for AP600 numerical model benchmarking.