Measurement of void fraction by fast neutrons

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6238048

Ghavi, M R

This study explores the feasibility of using fast neutron moderation and scattering, and attenuation as means for measurement of void fraction in hydrogenous two phase flow. Various geometries and different size channels were tested to examine the adaptability of the method to different arrangements. Experiments with static and dynamic voids were performed. For static tests, two phase air-water mixtures were simulated using various size plexiglass mock-ups in cylindrical channels. In dynamic experiments, the neutron techniques were tested in actual air water mixtures using different size cylindrical channels. A small californium-252 source was used as the source of neutrons. Theoretical modeling and calculations were performed through usage of DOT III multi-group neutron transport code and also two group neutron transport approximation. The results indicate suitability of the proposed techniques for measurement of void fraction in hydrogenous two phase mixtures. The test results show that accuracies of within +-8% can be expected for void fraction values ranging from 0 to 100%. The discussed methods appear to be fairly independent of void fraction distribution in two phase mixtures. The results also prove that no generalization concerning the response of neutron gauges can be made. Each gauge needs to be calibrated individually and on a case-by-case basis with respect to the geometrical arrangement involved. The feasibility of utilization of a small Cf-252 neutron source for void fraction measurements was demonstrated as the neutron flux provided by the small source used in this study proved to be adequate.

• Research Organization: Arkansas Univ., Little Rock (USA)
• OSTI ID: 6238048
• Country of Publication: United States
• Language: English

Related Subjects

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47 OTHER INSTRUMENTATION
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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
AIR
ALPHA DECAY RADIOISOTOPES
BARYONS
CALIFORNIUM 252
CALIFORNIUM ISOTOPES
COMPUTER CODES
D CODES
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
FAST NEUTRONS
FERMIONS
FLUID FLOW
FLUIDS
GASES
HADRONS
HEAVY NUCLEI
HYDROGEN COMPOUNDS
ISOTOPES
MEASURING METHODS
NEUTRAL-PARTICLE TRANSPORT
NEUTRON TRANSPORT
NEUTRONS
NUCLEI
NUCLEONS
OXYGEN COMPOUNDS
RADIATION TRANSPORT
RADIOISOTOPES
TWO-PHASE FLOW
VOID FRACTION
WATER
YEARS LIVING RADIOISOTOPES