ASTM: D1943: Alpha Particle Radioactivity of Water
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Official Method Name
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Standard Test Method for Alpha Particle Radioactivity of Water |
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Current Revision
| 1996 |
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Media
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WATER |
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Instrumentation
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Alpha Gas Particle Counter |
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Method Subcategory
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Radiochemical |
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Method Source
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Citation
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Brief Method Summary
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The test sample is reduced by evaporation or a suitable chemical method to the minimum weight of material having measurable alpha activity. Alpha radioactivity is measured by an instrument composed of a detecting device, amplifier, power supply, and scaler - the most widely used being proportional and scintillation counters. |
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Scope and Application
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This test method covers the measurement of alpha particle activity of water. It is applicable to alpha emitters having maximum energies above 3.9 MeV and at activity levels above 0.02 Bq/mL of radioactive homogeneous water. This test method is not applicable to samples containing alpha-emitting radionuclides that are volatile under conditions of the analysis. This test method can be used for either absolute or relative determinations. In tracer work, the results may be expressed by comparison with a standard that is defined to be 100%. For radioassay, data may be expressed in terms of alpha disintegration rates after calibration with a suitable standard. |
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Applicable Concentration Range
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> 0.02 Bq/mL |
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Interferences
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Solids content in the sample containing the alpha emitter produces significant losses in sample counting rates of about 10 to 15 % at 1 mg/cm2. Liquid samples shall be evaporated to dryness onto dishes that allow the sample to be counted directly by the detector. Solids on the dish shall remain constant in amount between related test samples, and should duplicate the density of the solids of the plated standard. |
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Quality Control Requirements
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Before this test method is utilized for the analysis of samples, a counter quality control or tolerance chart shall be established to ensure that the counting system is operating within prescribed limits. Prepare a quality control or tolerance chart as recommended in Practice D 3648. The counting system shall be checked by analyzing a QC source daily or prior to use. Evaluate the counting system background periodically. The background data shall be maintained in a logbook or plotted on a trend chart. Precision and bias can be assessed in the following manner: the precision of an individual measurement can be approximated by the total propagated uncertainty and bias can be assessed by the analysis of NIST traceable spiked samples with known quantities of radioactivity. |
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Sample Handling
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Collect the sample in accordance with Practices D 3370. Preserve the sample in a radioactive homogeneous state. A sample shall be made radioactive homogeneous by addition of a reagent in which the radionuclides or compounds of the radionuclides present would be soluble in large concentrations. Addition of acids, complexing agents, or stable chemically similar carriers may be used to obtain homogeneity. Consideration of the chemical nature of the radionuclides and compounds present and the subsequent chemistry of the method shall indicate the action to be taken. |
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Maximum Holding Time
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Relative Cost
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$51 to $200 |
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Sample Preparation Methods
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