Development report: radiac system for measuring aqueous tritium concentration by the liquid scintillation method
This report describes the design, assembly, and testing of a room temperature bench-scale liquid scintillation system for aqueous tritium measurement. With this system, urine or water samples with tritium concentrations of 1 to 5 ..mu..Ci/L can be measured with 20% uncertainty in a typical counting time of 40 s to 3 min, depending on the background count rate, activity level, and degree of quench. Concentrations above 5 ..mu..Ci/L can be measured within 10% uncertainty in a typical counting time of less than 3 min. In water samples, tritium concentrations as low as 0.1 ..mu..Ci/L can be measured within 20% uncertainty in a typical counting time of 30 min, and within 30% uncertainty in less than 10 min. The minimum measurable activity can be changed from 1 ..mu..Ci/L to as little as 0.1 ..mu..Ci/L by a simple change in the operating program. The microprocessor collects, processes, and transmits data and also interacts with the operator, which minimizes the workload and thereby reduces the chance of operator-induced error. Very little training is required: the operator simply follows basic instructions on the display. A photomultiplier tube balance circuit maximizes counting efficiency and also eliminates the need for stocking matched pairs of photomultiplier tubes. The use of a fast coincidence gate eliminates the need for refrigerating the scintillator or storing it in the dark. The design of the system also allows the degree of quench for a particular sample to be determined without the use of a radioactive gamma source.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6357495
- Report Number(s):
- ORNL/TM-9290; ON: DE85003799
- Country of Publication:
- United States
- Language:
- English
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Development report: RADIAC systems for measuring aqueous tritium concentration by the liquid scintillation method (Engineering Materials)
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Related Subjects
400103* -- Radiometric & Radiochemical Procedures-- (-1987)
440100 -- Radiation Instrumentation
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
AQUEOUS SOLUTIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
COMPUTERS
DATA PROCESSING
DISPERSIONS
ELECTRONIC CIRCUITS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
LIQUID SCINTILLATION DETECTORS
MATERIALS
MEASURING INSTRUMENTS
MICROELECTRONIC CIRCUITS
MICROPROCESSORS
MIXTURES
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PHOTOMULTIPLIERS
PHOTOTUBES
PROCESSING
RADIATION DETECTORS
RADIOISOTOPES
SCINTILLATION COUNTERS
SOLUTIONS
TRITIUM
URINE
WASTES
WATER
YEARS LIVING RADIOISOTOPES