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20 Cards in this Set
- Front
- Back
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State the primary objectives of an air monitoring program |
•To measure the concentration of the radioactive contaminant(s) in the air by collection and analysis •To identify the type and physical characteristics of the radioactive contaminate. •To help evaluate the hazard to the worker •To evaluate the performance of airborne radioactivity control measures •To assess air concentration data to determine if bioassay sampling should be initiated to verify whether an exposure has occurred and if so, to determine the magnitude of the exposure |
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State three physical states of airborne radioactive contaminas |
Particulates Gases Vapors |
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State the primary considerations to ensure a representative air sample is obtained |
•point of concern |
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Isokinetic sampling (as associated with airborne radioactivity sampling) |
When the sample line velocity is equal to the system velocity at the sample point |
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6 methods of obtaining samples or measurements of airborne radioactivity concentrations |
Filtration Volumetric Impaction/impingement Adsorption Condensation/dehumidification In-line/flow-through detection |
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Filtration |
Filter samples employ filtration of the air as the method of concentrating the airborne radioactive particulate (aerosol) contaminants. Most common sampling method employed for particulates because it is relatively simple and efficient. |
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Volumetric |
Employ a sample container into which the sample is drawn and isolated for analysis. Can be drawn in by a vacuum pump, air mover, or the container can be fillies with water , isolated and taken to the sample location. |
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Impaction/Impingement |
Concentrate particulates contaminants on a prepared surface by abruptly changing direction of the air flow at some point in the sampler. Particles are collected on a selected surface as the airstream is sharply deflected. |
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Adsorption |
These sampling devices concentrate the contaminants by causing them to adhere to the surface of the adsorption medium. Adsorption is the adhesion of a substance to the surface of another substance through chemical bonding. Uses an air mover to draw and collet the sample through the adsorption material. |
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Condensation/Dehumidification |
Employ a cold trap to condense water vapors in the sampled atmosphere and provide a liquid sample for further analysis. The collected water is frequently analyzed using a liquid scintillation counter. |
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In-Line/Flow-through Detection |
Employ an air mover to direct the sample air flow through or past the detection device. This method is employed for radionuclides which are difficult to collect or detect by other means. Used to measure gaseous activity after filtration and adsorption have been accomplished |
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Multipurpose Sampler and Monitors |
The various sampling methods described above may be combined into one sampler or monitor. These advantages are; •one vacuum pump supplies the air for all the samples. •All the samples are drawn at the same time to minimize the amount of time spent by the technician drawing samples |
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Describe the general considerations for selection of an air monitoring method |
•environmental conditions whet the sample is to be obtained •physical characteristics of the area •the energy and type of radiation of the radionuclide being monitored •the expected concentration level •the physical state of the airborne contaminant •the type of survey required •procedural requirements |
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Personal air samplers |
Provide and estimate of the airborne radioactivity concentration in the air the worker is breathing during the sampling period. |
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High volume/Flow rate samplers |
Provide and estimate of the airborne radioactivity concentration at a particular location in a short period of time |
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Low volume/flow rate samplers |
Provides and estimate of airborne radioactivity concentrations averaged over a long period of time at a particular location. |
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Portable continuous air monitors |
Provide and estimate of airborne radioactivity concentrations averaged over time at a particular location and provide immediate readout and alarm capabilities for preset concentrations. |
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Installed continuous air monitors (CAMs) |
Provide an estimate of airborne radioactivity concentrations averaged over time at a fixed, designated location and provide immediate and remote readout and alarm capabilities for preset concentrations. |
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Factors that affect the accuracy of airborne radioactivity measurements |
1. Sample is not representative of the atmosphere being sampled 2. Sample is not representative of the air being breathed by the worker 3. Incorrect or improperly installed sampling media for the selected sampler causing leak or improper flow rates. 4. Malfunctioning, Miss-operated, it miss-calibrated sampling device, causing errors in the flow rate measurements 5. Accuracy and operation of the timing device, causing errors in the time value 6. Accuracy and operation of the flow rate measuring device, causing errors in the flow rate value 7. Mishandling is the sample media, causing cross-contamination or removal of sample material 8. Changes in the collection efficiency of the medium due to sample loading, humidity, and other factors 9. Improper use or selection of analysis equipment 10. Inherent errors in the counting process due to sample geometry, self -absorption, resolving time, backscatter and statistical variations 11. Mathematical errors during calculations due to rounding of numbers and simple mistakes 12. Incorrect marking of samples and inaccurate recording of data |
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Describe the industry air monitoring program that includes monitoring frequencies calculation methods applicable derived air concentration limits and methods for determining radon interference |
.3 DAC, or when an individual is likely to receive more thank 40 DAC hours abyear |
