ASTM C1168-23

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1168 − 23
Standard Practice for
Preparation and Dissolution of Plutonium Materials for
1
Analysis
This standard is issued under the fixed designation C1168; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope the analyses must be of high precision, such as plutonium
assay; otherwise they are dispensed on a volume basis.
1.1 This practice is a compilation of dissolution techniques
1.2 Procedures in this practice are intended for the dissolu-
for plutonium materials that are applicable to the test methods
tion of plutonium metal, plutonium oxide, and uranium-
used for characterizing these materials. Dissolution treatments
plutonium mixed oxides. Aliquots of dissolved materials are
for the major plutonium materials assayed for plutonium or
analyzed using test methods, such as those developed by
analyzed for other components are listed. Aliquots of the
Subcommittee C26.05 on Methods of Test, to demonstrate
dissolved materials are dispensed on a mass basis when one of
compliance with applicable requirements. These may include
product specifications such as Specifications C757 and C833.
1.3 One or more of the procedures in this practice may be
1
This practice is under the jurisdiction of ASTM Committee C26 on Nuclear
applicable to unique plutonium materials, such as alloys,
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
Test.
compounds, and scrap materials. The user must determine the
Current edition approved Oct. 1, 2023. Published October 2023. Originally
applicability of this practice to such materials.
approved in 1990. Last previous edition approved in 2015 as C1168 – 15. DOI:
10.1520/C1168-23. 1.4 The treatments, in order of presentation, are as follows:
Procedure Number Procedure Title Section
1 Dissolution of Plutonium Metal with Hydrochloric Acid at Room 9
Temperature
2 Dissolution of Plutonium Metal with Hydrochloric Acid and Heating 10
3 Dissolution of Plutonium Metal with Sulfuric Acid 11
4 Dissolution of Plutonium Oxide and Uranium-Plutonium Mixed 12
Oxide by the Sealed-Reflux Technique
5 Dissolution of Plutonium Oxide and Uranium-Plutonium Mixed 13
Oxides by Sodium Bisulfate Fusion
6 Dissolution of Uranium-Plutonium Mixed Oxides and Low-Fired 14
Plutonium Oxide in Beakers
7 Open-Vessel (with Reflux Condenser) Dissolution of Plutonium 15
Oxide Powder
8 Open-Vessel (with Reflux Condenser) Dissolution of Mixed Oxide 16
Powder
9 Closed-Vessel Hot Block Dissolution of Plutonium Oxide Powder 17
10 Open-Vessel (with Reflux Condenser) Dissolution of Mixed Oxide 18
Pellets
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C1168 − 23
1.5 The values stated in SI units are to be regarded as 4. Summary of Dissolution Procedures
standard. The non-SI unit of molarity (M) is also to be regarded
4.1 Most plutonium-containing materials are dissolved with
as standard. Values in parentheses (non-SI units), where
various mineral acids and, except for plutonium metal, with
provided, are for information only and are not considered
applied heat. In some cases, dissolution-resistant materials are
standard.
dissolved in heated and sealed containers in which pressuriza-
1.6 This standard does not purport to address all of the
tion provides a higher temperature than is attained at ambient
safety concerns, if any, associated with its use. It is the
pressure.
responsibility of the user of this standard to establish appro-
4.2 The dissolved materials are quantitatively transferred to
priate safety, health, and environmental practices and deter-
a tared polyethylene dispensing bottle for subsequent deliveries
mine the applicability of regulatory limitations prior to use.
of weighed aliquots for high-precision analysis methods, such
1.7 This international standard was developed in accor-
as assays, or to a volumetric flask for deliveries of volume
dance with internationally recognized principles on standard-
aliquots for less precise analysis methods, such as impurity
ization established in the Decision on Principles for the
analyses. Dilute acids are used as rinses to effect quantitative
Development of International Standards, Guides and Recom-
transfers and as diluents in the polyethylene dispensing bottles
mendations issued by the World Trade Organization Technical
and volumetric flasks. The use of
...