ASTM D3972-97

Standard Test Method for Isotopic Uranium in Water by Radiochemistry

SCOPE
1.1 This test method covers the determination of alpha-particle-emitting isotopes of uranium in water by means of chemical separations and alpha pulse-height analysis (also known as alpha-particle spectrometry). Uranium is chemically separated from a water sample by coprecipitation with ferrous hydroxide, anion exchange, and electrodeposition. The test method applies to soluble uranium as well as to any uranium that might be present in suspended matter in the water sample. This test method is applicable for uranium processing effluents as well as substitute ocean water. When suspended matter is present, an acid dissolution step is added to assure that all of the uranium dissolves. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific warning statements are given in Section 9.

General Information

• Status: Historical
• Publication Date: 09-Feb-2002
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.04 - Methods of Radiochemical Analysis

Relations

• Replaced By: ASTM D3972-02 - Standard Test Method for Isotopic Uranium in Water by Radiochemistry
• Effective Date: 10-Feb-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: D 3972 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
1
Isotopic Uranium in Water by Radiochemistry
This standard is issued under the fixed designation D 3972; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
,
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1. Scope these reference may be made to other published glossaries.
1.1 This test method covers the determination of alpha-
4. Summary of Test Method
particle-emitting isotopes of uranium in water by means of
4.1 The water sample to be analyzed is acidified and
chemical separations and alpha pulse-height analysis (also
uranium-232 is added to serve as an isotopic tracer before any
known as alpha-particle spectrometry). Uranium is chemically
additional operations are performed. If the sample is a seawater
separated from a water sample by coprecipitation with ferrous
sample, or if it contains carbonate or bicarbonate ions, the
hydroxide, anion exchange, and electrodeposition. The test
sample must be boiled under acidic conditions to convert these
method applies to soluble uranium as well as to any uranium
ions to carbon dioxide gas which is then expelled from the
that might be present in suspended matter in the water sample.
solution. Carbonate ions must not be present during the
This test method is applicable for uranium processing effluents
precipitation step because they complex the uranium and
as well as substitute ocean water. When suspended matter is
prevent its coprecipitation. The uranium is coprecipitated from
present, an acid dissolution step is added to assure that all of
the sample with ferrous hydroxide. This precipitate is dissolved
the uranium dissolves.
in concentrated hydrochloric acid, or is subjected to an acid
1.2 This standard does not purport to address all of the
dissolution with concentrated nitric and hydrofluoric acids if
safety concerns, if any, associated with its use. It is the
the hydrochloric acid fails to dissolve the precipitate.
responsibility of the user of this standard to establish appro-
4.2 The uranium is separated from other radionuclides by
priate safety and health practices and determine the applica-
adsorption on anion-exchange resin from hydrochloric acid
bility of regulatory limitations prior to use. Specific warning
(2+1), followed by elution with hydrochloric acid (1+119). The
statements are given in Section 9.
uranium is electrodeposited onto a stainless steel disk. Isotopic
uranium radioactivities are measured by alpha pulse-height
2. Referenced Documents
analysis with a silicon surface-barrier or ion-implanted detector
and a multichannel analyzer.
2.1 ASTM Standards:
2
4.3 When uranium-232 is used as the tracer, the other
C 859 Terminology Relating To Nuclear Materials
3
isotopes of uranium listed in Table 1 can be detected in the
D 1129 Terminologies Relating to Water
3
alpha-particle spectrum of an unknown sample. From the alpha
D 1193 Specification for Reagent Water
energies given in the table, it can be seen that the alpha energy
D 2777 Practice for Determination of Precision and Bias of
3
of uranium-232 is more than 0.40 MeV higher than the energy
Applicable Methods of Committee D–19 on Water
4
of any other uranium isotope. Thus, there should be little
D 3084 Practice for Alpha-Particle Spectrometry of Water
3
interference from tailing of the uranium-232 into the lower
D 3370 Practices for Sampling Water
4
energy alpha peaks. Uranium-233 and uranium-234 usually
D 3648 Practices for the Measurement of Radioactivity
cannot be resolved because their principal alpha energies differ
by only 0.04 MeV. Uranium-235 and uranium-236 peaks can
3. Terminology
be resolved only with difficulty. The alpha peaks from other
3.1 Definitions:
combinations of uranium isotopes can be resolved unless the
3.1.1 For definitions of terms used in this test method, refer
quality of the finally prepared sample is poor.
to Terminologies C 859 and D 1129. For terms not included in
5. Significance and Use
5.1 This test method was developed to measure the radio-
activity of uranium isotopes in environmental waters or waters
1
This test method is under the jurisdiction of ASTM Committee D–19 on Water
released to the environment, and to determine whether the
and is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-
cal Analysis.
Current edition approved Aug. 10, 1997. Published October 1997. Originally
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published as D 3972 – 80. Last previous edition D 3972 – 90. Parker, S. P., ed., McGraw-Hill Dictio
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