The 5th benchmark of CFD applications to Nuclear reactor safety has been approved by CSNI. Its main objective is to go a step further in the application of single-phase CFD to nuclear safety issues with mixing problems possibly in presence of buoyancy effects.
The Pressurized Thermal Shock (PTS) Facility can simulate some mixing phenomena of cold water and hot water in a horizontal cold leg of PWR as encountered in some accidental situations with ECCS injection. A reactor-like geometry of the cold-leg-downcomer junction has been implemented in the facility This allows to test uncertainty quantification methods in conditions closer to real reactor applications.
The facility is equipped with the state-of-the-art instrumentation and measurement techniques to provide high resolution measurements of velocity, concentrations, and pressure drops at different locations within the leg, nozzle, and downcomer.
Experimental results of open and blind tests are summarized in the article “Experimental Measurements of Flow Mixing in Cold Leg of a Pressurized Water Reactor” published in Annals of Nuclear Energy (https://doi.org/10.1016/j.anucene.2019.107137),
Our laboratory has performed simulations with advanced computational tools. See the numerical and experimental comparison in the video below.
Additional information on experimental facility, tests, and data are available for download from the link below. The access is password protected.