Separate-Effects Experiments on the Hydrodynamics of Air Ingress Phenomena for the Very High Temperature Reactor
NURETH-14 - 2011 September 25-30

Presented at:
2011 September 25-30
Toronto, Canada
Session Title:
G4-2 - Gas Cooled Fast Reactors and Very High Temperature Reactors; System Calculations

Seungjin Kim (The Pennsylvania State University)
Justin Talley (The Pennsylvania State University)
Mohan Yadav (The Pennsylvania State University)
Andrew Ireland (US Nuclear Regulatory Commission)
Stephen M. Bajorek (U.S. Nuclear Regulatory Commission)


The present study performs scaled separate-effects experiments to investigate the

hydrodynamics in the air-ingress phenomena following a Depressurized Condition Cooldown in

the Very High Temperature Gas-Cooled Reactor. First, a scoping experiment using water and

brine is performed. The volumetric exchange rate is measured using a hydrometer, and flow

visualizations are performed. Next, Helium-air experiments are performed to obtain threedimensional

oxygen concentration transient data using an oxygen analyzer. It is found that there

exists a critical density difference ratio, before which the ingress rate increases linearly with time

and after which the ingress rate slows down significantly. In both the water-brine and Helium-air

experiments, this critical ratio is found to be approximately 0.7.

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