Overview
EN ISO 18417:2019 (ISO 18417:2017) specifies a laboratory method for defining a sorption capacity index for iodine charcoal sorbents used in nuclear applications. The standard applies to granulated and crushed activated-charcoal sorbents intended for trapping gaseous radioiodine and its compounds. It is adopted by CEN (as EN ISO 18417:2019) and targets manufacturers and operators who need to measure actual sorbent performance under controlled conditions.
Key topics and requirements
- Scope and applicability: Covers sorbents for nuclear power plants, research reactors, laboratories (including nuclear medicine), and sampling equipment on sample lines.
- Laboratory focus: The document describes laboratory test methods only (not in situ system tests).
- Test principles: Defines how to establish and measure the kinetic behaviour of sorbents via a sorption capacity index based on radioiodine activity distribution within the sorbent sample.
- Test preparation: Includes requirements for sample preparation, removal of air impurities and humidity, and ensuring equilibrium conditions before measurement.
- Test agent: Radioactive methyl iodide is referenced as a test agent used for sorbent evaluation.
- Measurement and instrumentation: Specifies measuring devices and procedures to determine distribution of radioiodine in the sorbent and to calculate the index.
- Performance and reporting: Covers test execution, calculation of the sorption capacity index, uncertainty considerations, and standardized test-report formats (normative annexes provide report templates and example results).
Practical applications
- Quality control for sorbent manufacturers: Validate new batches, compare sorbent formulations, and document performance specifications using a standardized sorption capacity index.
- Plant operators and safety teams: Assess whether a given activated-charcoal sorbent is suitable for use in off‑gas cleaning, ventilation filters, and iodine retention systems under specified laboratory conditions.
- Laboratories and sampling systems: Verify sorbents used in radiochemistry, nuclear medicine, and monitoring sample lines.
- Regulatory and procurement: Provide reproducible, comparable data to support procurement decisions and regulatory compliance related to radiation protection (ICS 13.280).
Related information
- Standard prepared by ISO/TC 85 (Nuclear energy, nuclear technologies, radiological protection) and adopted by CEN/TC 430.
- Use in conjunction with facility-specific systems testing (in situ tests) and applicable radiation-protection requirements; consult national regulations and other ISO/CEN standards relevant to airborne radioactive effluents and filter testing where needed.
Keywords: EN ISO 18417, ISO 18417:2017, iodine charcoal sorbents, sorption capacity index, radioiodine, activated charcoal, nuclear facilities, laboratory sorbent testing.