Significance and Use

Mixed oxide, a mixture of uranium and plutonium oxides, is used as a nuclear-reactor fuel in the form of pellets. The plutonium content may be up to 10 weight %, and the diluent uranium may be of any ²³⁵ U enrichment. In order to be suitable for use as a nuclear fuel, the material must meet certain criteria for combined uranium and plutonium content, effective fissile content, and impurity content as described in Specification C833 .

The material is assayed for uranium and plutonium to determine whether the plutonium content is as specified by the purchaser, and whether the material contains the minimum combined uranium and plutonium contents specified on a dry weight basis.

Determination of the isotopic content of the plutonium and uranium in the mixed oxide is made to establish whether the effective fissile content is in compliance with the purchaser's specifications.

Impurity content is determined to ensure that the maximum concentration limit of certain impurity elements is not exceeded. Determination of impurities is also required for calculation of the equivalent boron content (EBC).

1. Scope

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade mixed oxides, (U, Pu)O ₂ , powders and pellets to determine compliance with specifications.

1.2 The analytical procedures appear in the following order:

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.4 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. (For specific safeguard and safety precaution statements, see Sections 11, 20, 64, and 112 and 102.6.1.)

7.1 This test method covers the determination of 5 to 100 ? g/g of nitride nitrogen in mixtures of plutonium and uranium oxides in either pellet or powder form.

15.1 This test method covers the determination of 10 to 200 ? g of residual carbon in nuclear grade mixed oxides, (U,Pu)O ₂ .

27.1 This test method is applicable to the determination of 5 to 100 ? g/g of chlorine and 1 to 100 ? g/g of fluorine in 1-g samples of nuclear-grade mixed oxides, (U, Pu)O ₂ .

35.1 This test method covers the determination of sulfur in the concentration range from 10 to 600 ? g/g for samples of nuclear-grade uranium and plutonium mixed oxides, (U, Pu)O ₂ .

44.1 This test method covers the determination of moisture in nuclear-grade mixed oxides of uranium and plutonium (U,Pu)O ₂ . Detection limits are as low as 10 ? g.

52.1 This test method covers the determination of rare earths in uranium-plutonium dioxide over the range from 10 to 200 ? g/g.

60.1 This test method covers the analysis of uranium-plutonium dioxide [(U, Pu)O ₂ ] for the 25 elements in the ranges indicated in Table 1, using gallium oxides or sodium fluoride as the carrier. (See also Table 2.)

70.1 This test method covers the spark source spectrographic analysis of uranium and plutonium dioxide for impurity elements. Because of its extreme sensitivity, it may be the most practical test method for the determination of certain impurities whose concentration is below the detectable limits of other spectrographic methods.

77.1 This test method covers the measurement of volatiles other than water in reactor-grade mixed dioxide pellets. The lower limit of the test method using the described equipment and a sample of approximately 1 g is 0.01 cm ³ per gram of sample at STP conditions (23).

85.1 This test method covers the determination of 5 to 150 ? g of tungsten in 1-g samples of nuclear-grade uranium and plutonium mixed oxides (U, Pu)O ₂ (24).

94.1 This test method covers the determination of dysprosium, europium, gadolinium, and samarium in mixed oxides of uranium and plutonium over the concentration range from 0.1 to 10 ? g/g of mixed oxide.

98.1 This test method covers the determination of the isotopic composition of uranium and plutonium in nuclear-grade mixed oxides ((U, Pu)O ₂ ).

107.1 This test method covers the determination of the oxygen-to-metal atom ratio (O/M) in sintered mixed oxide pellets and powders.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C697 Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Plutonium Dioxide Powders and Pellets

C833 Specification for Sintered (Uranium-Plutonium) Dioxide Pellets

C852 Guide for Design Criteria for Plutonium Gloveboxes

C1008 Specification for Sintered (Uranium-Plutonium) Dioxide Pellets--Fast Reactor Fuel

C1009 Guide for Establishing a Quality Assurance Program for Analytical Chemistry Laboratories Within the Nuclear Industry

C1068 Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry

C1108 Test Method for Plutonium by Controlled-Potential Coulometry

C1128 Guide for Preparation of Working Reference Materials for Use in Analysis of Nuclear Fuel Cycle Materials

C1156 Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials

C1165 Test Method for Determining Plutonium by Controlled-Potential Coulometry in H2SO4 at a Platinum Working Electrode

C1168 Practice for Preparation and Dissolution of Plutonium Materials for Analysis

C1204 Test Method for Uranium in Presence of Plutonium by Iron(II) Reduction in Phosphoric Acid Followed by Chromium(VI) Titration

C1206 Test Method for Plutonium by Iron (II)/Chromium (VI) Amperometric Titration

C1210 Guide for Establishing a Measurement System Quality Control Program for Analytical Chemistry Laboratories Within the Nuclear Industry

C1268 Test Method for Quantitative Determination of Americium 241 in Plutonium by Gamma-Ray Spectrometry

C1297 Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials

C1415 Test Method for 238Pu Isotopic Abundance By Alpha Spectrometry

C1432 Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis

D1193 Specification for Reagent Water

E60 Practice for Analysis of Metals, Ores, and Related Materials by Spectrophotometry

E115 Practice for Photographic Processing in Optical Emission Spectrographic Analysis

E116 Practice for Photographic Photometry in Spectrochemical Analysis

Keywords

Carbon content--nuclear materials; Chloride analysis--nuclear applications; Fluoride content; Isotopic analysis; Mass spectrometry--nuclear materials/applications; Mixed oxides (MOX); Moisture analysis--nuclear materials; Nitrogen content--nuclear materials; Plutonium--isotopic analysis; Rare earth content; Spectrochemical analysis; Sulfur--nuclear materials; Trace elements--spectrochemical analysis; Tungsten content; Uranium content; Volatile matter content--nuclear materials;

ICS Code

ICS Number Code 27.120.30 (Fissile materials and nuclear fuel technology)

DOI: 10.1520/C0698-10

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ASTM C698