ASTM E318-91 PDF

Full title and description

Standard Test Method for Uranium in Aqueous Solutions by Colorimetry — ASTM E318-91. This short procedural standard describes a colorimetric analytical technique for the quantitative determination of uranium in known volumes of aqueous solutions, primarily arising from processing of irradiated nuclear fuel and laboratory studies on irradiated uranium.

Abstract

ASTM E318-91 specifies reagents, sample preparation, measurement conditions, and acceptance criteria for a colorimetric assay to determine uranium content in aqueous aliquots. The method gives detection capability down to sub-microgram levels with best precision at moderate microgram masses, and notes known chemical interferences and recommended sample handling limits. The original 1991 document was brief (four pages) and was withdrawn in 1996; users are advised to consult current ASTM or international standards for modern alternatives.

General information

• Status: Withdrawn (withdrawn 1996).
• Publication date: January 1, 1991 (designated E318-91).
• Publisher: ASTM International (American Society for Testing and Materials).
• ICS / categories: 27.120.30 — Fissile materials and nuclear fuel technology (radiochemical methods for uranium).
• Edition / version: E318-91 (1991 edition).
• Number of pages: 4.

Scope

This test method covers the quantitative determination of uranium in known volumes of aqueous solutions that contain radioactive nuclides (solutions from irradiated fuel processing and related laboratory studies). Applicability is limited practically to samples that contain a minimum of about 30 µg of uranium per sample for routine precision, although the method can detect as little as ~0.5 µg with reduced precision. Highest precision is reported when about 50–75 µg of uranium is present in the test aliquot. At concentrations above about 750 µg/mL dilutions are required; the described procedure is presented for sample aliquots of 1 mL or less but reagent volumes can be scaled. The method lists known ionic interferences (thorium and cerium(IV) at high relative concentrations) and gives tolerance ratios for many common ions and anions. Users must follow appropriate radiochemical safety and handling practices.

Key topics and requirements

• Colorimetric reaction chemistry and specified reagents for uranium complexation and color development.
• Sample aliquot size and recommended concentration ranges (typical aliquot ≤1 mL; optimal uranium mass 50–75 µg; minimum practical ~30 µg; detection ~0.5 µg).
• Calibration and quantitation procedures to obtain quantitative results with stated precision limits.
• Interference identification and tolerance limits (notably thorium and cerium(IV); lists of tolerant and interfering cations/anions and their approximate ratios).
• Requirements for dilution or concentration of samples when outside specified ranges.
• Safety and radioactive-material handling notes relevant to processing irradiated-fuel solutions.

Typical use and users

Primary users include radiochemistry laboratories, nuclear fuel cycle process-control and assay laboratories, research laboratories working with irradiated uranium solutions, and specialized analytical facilities performing uranium determinations by wet-chemistry/colorimetric methods. The method is intended for analyses associated with irradiated fuel processing and laboratory studies rather than routine environmental monitoring at trace-ng/L levels.

Related standards

ASTM E318-91 is one of several historical ASTM radiochemical methods for actinide assay. Related or subsequent standards and methods of interest include ASTM E267 (uranium and plutonium concentrations and isotopic abundances — withdrawn), other actinide assay practices, and modern replacement or complementary techniques such as hybrid K‑Edge densitometry/X‑ray fluorescence methods (for example ASTM C1855). Users should consult current ASTM committee publications for the latest validated methods and any direct replacements.

Keywords

uranium, colorimetry, radiochemistry, aqueous solutions, irradiated fuel, assay, uranium determination, interference, calibration, ASTM E318-91.

FAQ

Q: What is this standard?

A: ASTM E318-91 is a short ASTM test method (1991) that describes a colorimetric procedure for determining uranium in aqueous solutions, particularly those originating from irradiated nuclear fuel processing.

Q: What does it cover?

A: It covers reagents, sample aliquot sizes, concentration ranges, calibration, precision expectations, and known chemical interferences for the colorimetric assay of uranium in aqueous aliquots (practical minimum ~30 µg, detection near 0.5 µg, best precision at ~50–75 µg).

Q: Who typically uses it?

A: Radiochemists, nuclear fuel-cycle laboratories, research groups handling irradiated uranium solutions, and specialized analytical labs performing wet-chemistry uranium assays.

Q: Is it current or superseded?

A: ASTM E318-91 was withdrawn in 1996 and is not an active ASTM standard. Laboratories should use current validated methods (consult ASTM committee publications and modern methods such as hybrid K‑Edge/XRF techniques) for regulatory or high‑accuracy work.

Q: Is it part of a series?

A: It is one of a group of ASTM test methods and practices addressing radiochemical assay and nuclear materials analysis; several neighboring ASTM designations address related assays and matrices. Users commonly consult the ASTM nuclear materials and radiochemistry committee outputs for related procedures.

Q: What are the key keywords?

A: uranium, colorimetry, aqueous solutions, irradiated fuel, radiochemistry, assay, interference, calibration, ASTM E318-91.