ASTM C1832-16
Standard Test Method for Determination of Uranium Isotopic Composition by the Modified Total Evaporation (MTE) Method Using a Thermal Ionization Mass Spectrometer

Standard No.

ASTM C1832-16

Release Date

2016

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM C1832-21

Latest

ASTM C1832-23

Scope

5.1 Uranium material is used as a fuel in certain types of nuclear reactors. To be suitable for use as nuclear fuel, the starting material shall meet certain specifications such as those described in Specifications C753, C776, C787, C833, C967, C996, and C1008, or as specified by the purchaser. The isotope amount ratios of uranium material can be measured by mass spectrometry following this test method to ensure that they meet the specification.

5.2 The MTE method can be used for a wide range of sample sizes even in samples containing as low as 50 μg of uranium. If the uranium sample is in the form of uranium hexafluoride, it can be converted into a uranium nitrate solution for measurement by the MTE method. The concentration of the loading solution for MTE has to be in the range of 1 to 6 mg/g to allow a sample loading of 2 to 6 μg of uranium. A minimum loading of 3 μg uranium per filament is recommended. This is needed to have a suitable ion signal especially for the two minor isotopes (²³⁴U and ²³⁶U) thus enabling the internal calibration of SEM versus the Faraday cups during the measurement.

5.3 Until now, the instrument capabilities for the MTE method have only been implemented on the TRITON™ TIMS instrument.5 Therefore all recommendations for measurement parameters in this test method are specified for the TRITON™ TIMS instrument. The manufacturers of other TIMS instruments (for example, IsotopX and Nu Instruments) have plans to implement the modifications needed in their instruments to use the MTE method.

5.4 The MTE method described here can also be extended to measurement of elements other than uranium. Note that the MTE method has already been implemented for plutonium and calcium.

1.1 This test method describes the determination of the isotope amount ratios of uranium material as nitrate solutions by the modified total evaporation (MTE) method using a thermal ionization mass spectrometer (TIMS) instrument.

1.2 The analytical performance in the determination of the ²³⁵U/²³⁸U major isotope amount ratio by MTE is similar to the (“classical”) total evaporation (TE) method as described in Test Method C1672. However, in the MTE method, the evaporation process is interrupted on a regular basis to allow measurements and subsequent corrections for background form peak tailing, perform internal calibration of a secondary electron multiplier (SEM) detector versus the Faraday cups, peak centering, and ion source refocusing. Performing these calibrations and corrections on a regular basis during the measurement, improves precision, and significantly reduces uncertainties for the minor isotope amount ratios ²³⁴U/²³⁸U and ²³⁶U/²³⁸U as compared to the TE method.

1.3 In principle, the MTE method yields major isotope amount ratios without the......

ASTM C1832-16 Referenced Document

• ASTM C1008 Standard Specification for Sintered (Uranium-Plutonium) Dioxide
  Pellets&x2014;Fast Reactor Fuel
• ASTM C1068 Standard Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry
• ASTM C1128 Standard Guide for Preparation of Working Reference Materials for Use in the Analysis of Nuclear Fuel Cycle Materials
• ASTM C1156 Standard Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
• ASTM C1347 Standard Practice for Preparation and Dissolution of Uranium Materials for Analysis
• ASTM C1411 Standard Practice for the Ion Exchange Separation of Uranium and Plutonium Prior to Isotopic Analysis
• ASTM C1625 Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass Spectrometry
• ASTM C1672 Standard Test Method for Determination of the Uranium, Plutonium or Americium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer
• ASTM C753 Standard Specification for Nuclear-Grade, Sinterable Uranium Dioxide Powder
• ASTM C776 Standard Specification for Sintered Uranium Dioxide Pellets for Light Water Reactors
• ASTM C787 Standard Specification for Uranium Hexafluoride for Enrichment
• ASTM C833 Standard Specification for Sintered (Uranium-Plutonium) Dioxide Pellets
• ASTM C859 Standard Terminology Relating to Nuclear Materials
• ASTM C967 Standard Specification for Uranium Ore Concentrate
• ASTM C996 Standard Specification for Uranium Hexafluoride Enriched to Less Than 5% 235U1
• ASTM D1193 Standard Specification for Reagent Water
• ASTM E2586 Standard Practice for Calculating and Using Basic Statistics
• ASTM E2655 Standard Guide for Reporting Uncertainty of Test Results and Use of the Term Measurement Uncertainty in ASTM Test Methods

ASTM C1832-16 history

• 2023 ASTM C1832-23 Standard Test Method for Determination of Uranium Isotopic Composition by Modified Total Evaporation (MTE) Method Using Thermal Ionization Mass Spectrometer
• 2022 ASTM C1832-22 Standard Test Method for Determination of Uranium Isotopic Composition by Modified Total Evaporation (MTE) Method Using Thermal Ionization Mass Spectrometer
• 2021 ASTM C1832-21 Standard Test Method for Determination of Uranium Isotopic Composition by Modified Total Evaporation (MTE) Method Using Thermal Ionization Mass Spectrometer
• 2016 ASTM C1832-16 Standard Test Method for Determination of Uranium Isotopic Composition by the Modified Total Evaporation (MTE) Method Using a Thermal Ionization Mass Spectrometer