Abstract
An experimental study has been performed to investigate the off-take phenomena at the header-feeder systems (horizontal header pipe with multiple feeder branch pipes) in a CANDU (CANadian Deuterium Uranium) reactor with the branch orientation varies ±36° or ±72°. In order to evaluate the applicability of the conventional correlations used in the safety analysis code, RELAP5-Mod3, the test facility is designed with the 1/2 scale of the CANDU 6. It was found that the data set for the top, bottom and side branches are in a good agreement with the correlations used. However, for the specific angled branches, ±36° and ±72°, the onsets of off-take data and quality data showed large deviation with the conventional model inside RELAP5-MOD3. Furthermore, based on the uncertainty analysis, the conventional 2.5 power law needs to be modified. The present experimental data set can be useful for the construction of the general correlation considering the arbitrary branch orientation.
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Abbreviations
- D,d:
-
Diameter of header and diameter of branch pipe
- Fr:
-
Froude number
- g:
-
Gravitational acceleration
- h:
-
Water level
- j:
-
Volumetric velocity
- q:
-
The gas volumetric flow
- Q:
-
The volume flow rate
- r:
-
The rise of water level at the wall
- V:
-
Velocity
- x:
-
The quality
- α:
-
The void fraction
- δ:
-
The wave height
- λ:
-
Wave length
- ρ:
-
The density
- Δρ:
-
ρf-ρg
- *:
-
Dimensionless
- b:
-
Onset condition
- g:
-
Gas
- 3g:
-
The gas phase at the branch
- R:
-
Ratio of prototype to the reference
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Lee, J.Y., Hwang, GS. & Kim, M. Experimental investigation on onset criteria of liquid/gas entrainment in the header-feeder system of CANDU. J Mech Sci Technol 20, 1030–1042 (2006). https://doi.org/10.1007/BF02916002
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DOI: https://doi.org/10.1007/BF02916002