SIST EN ISO 15366-2:2016 PDF

Overview - EN ISO 15366-2:2016 (ISO 15366-2:2014)

EN ISO 15366-2:2016 is a CEN-adopted international standard for nuclear fuel technology that specifies chemical separation and purification procedures for uranium and plutonium in nitric acid solutions prior to isotopic and isotope-dilution analysis by techniques such as mass spectrometry or alpha spectrometry. It targets very low-level samples - plutonium and uranium in the nanogram range and below - and documents a solvent-extraction chromatography method using mini-columns coated with tri-n‑octylphosphine‑oxide (TOPO). The method’s detection limits were determined as ≈500 pg for both plutonium and uranium.

Key topics and technical requirements

• Scope and sample types: Dissolved solutions from irradiated light-water reactor fuel and high-activity liquid waste from spent fuel reprocessing plants.
• Separation principle: Extraction chromatography on disposable mini-columns with TOPO-coated supports (polyethylene or silica) in 3 mol·L−1 HNO3; selective retention of Pu(IV) and U(VI).
• Valency control: Use of iron(II) sulfate and sodium nitrite to adjust oxidation states prior to separation.
• Elution and purification:
  • Plutonium eluted after chemical reduction (e.g., ascorbic acid).
  • Uranium eluted with ammonium carbamate and further purified by anion exchange resin or fuming with concentrated HNO3.
• Column and support details: Mini-columns (disposable polypropylene) packed with polyethylene powder coated with TOPO; Annex A describes packing and conditioning.
• Quality and operational controls: Run blanks and control samples in parallel; work in clean conditions (laminar-flow fume hood or shielded glovebox); gravity flow rates should not exceed 0.4 mL·min−1.
• Reagents and apparatus: Suprapure-grade reagents (HNO3, HCl, TOPO in cyclohexane, ammonium carbamate, ascorbic acid, etc.), PTFE vials, shielded workspace and hotplates.

Practical applications and users

• Nuclear fuel and reprocessing laboratories performing isotopic analysis, isotope-dilution mass spectrometry and alpha spectrometry on ultra‑low-level uranium and plutonium samples.
• Radioanalytical and safeguards labs requiring validated separation methods for trace-level plutonium/uranium in spent fuel dissolution solutions and high-activity wastes.
• Environmental and forensic labs analyzing minute nuclear materials where robust separation and low detection limits (≈500 pg) are critical.

Related standards

• ISO 15366-1 - Part 1: procedures for higher amounts (microgram/milligram range).
• ISO 8299 - Guidance related to mass spectrometric isotopic analysis.
• ISO 11483 - Alpha spectrometry method references.

This standard is essential for practitioners implementing solvent extraction chromatography workflows for trace-level uranium and plutonium isotopic measurements, ensuring reproducible separation, low blank levels, and compatibility with downstream mass spectrometry or alpha spectrometry analysis.