2017 Annual Meeting

Presentation information

Oral presentation

III. Fission Energy Engineering » 304-1 Thermal Hydraulics, Energy Conversion, Energy Transfer, Energy Storage

[3K05-09] Thermal Hydraulics Extension

Wed. Mar 29, 2017 10:40 AM - 12:00 PM Room K (16-306 Building No.16)

Chair: Kenichi Katono (HGNE)

11:40 AM - 11:55 AM

[3K09] Study on Air Ingress Phenomena during a Depressurization Accident of VHTR

(1)Investigate on Mixing Process of Multicomponent Gases in a Reactor

*Tetsuaki Takeda1, Yudai Tanaka1 (1. University of Yamanashi)

Keywords:VHTR, depressurization accident, air ingress, natural convection, molecular diffusion

A depressurization accident is the one of the design-basis accidents of a Very-High-Temperature Reactor (VHTR). When the depressurization accident occurs, air is expected to enter into the reactor pressure vessel from the breach and oxidize in-core graphite structures. Therefore, it is important to know a mixing process of different kind of gases in the stable and unstable stratified fluid layer. In order to predict or analyze the air ingress phenomena during the depressurization accident, therefore, it is important to develop the method for prevention of air ingress during the accident. We have carried out an experiment to obtain the mixing process of two component gases and counter current flow characteristics.
The result obtained in the experiment has been simulated by the 3-D numerical analysis quantitatively. These flow characteristics is same as those of phenomena generated in the passage between a permanent reflector and a pressure vessel wall of the VHTR.