Overview
EN ISO 13165-1:2024 (identical to ISO 13165-1:2022) specifies a standardized test method using liquid scintillation counting (LSC) for determination of Radium-226 (Ra-226) activity concentration in water. Published by CEN and prepared by ISO/TC 147 “Water quality”, this European adoption supersedes EN ISO 13165-1:2020 and is intended for routine and regulatory water quality and radioactivity measurements.
Key topics and technical requirements
The standard covers the principles and practical requirements for LSC-based measurement of Ra‑226, including:
- Principle of measurement using liquid scintillation counting for Ra‑226.
- Reagents and equipment needed for sample preparation and LSC analysis.
- Sampling guidance for surface, groundwater, seawater and drinking water.
- Instrument set-up and calibration, including preparation of calibration sources and optimization of counting conditions.
- Detection efficiency assessment and blank sample preparation/measurement.
- Procedures: direct counting, thermal preconcentration, sample preparation and measurement steps.
- Quality control and validation: calibration, blanks, control samples, and documented validation data.
- Expression of results: calculation of massic activity, estimation of standard uncertainty, decision threshold and detection limit, and reporting of coverage intervals.
- Interference control to identify and mitigate radionuclide or chemical interferences.
- Test report content and reporting requirements.
These topics align with ISO/IEC Guide 98-3 principles for uncertainty and reference international guidance (e.g., WHO).
Applications
EN ISO 13165-1:2024 is applicable where accurate measurement of Ra‑226 in water is required:
- Drinking water monitoring to assess compliance with guidance levels (WHO guidance level for Ra in drinking water is cited in the standard).
- Environmental surveillance of surface waters, groundwaters and seawater.
- Effluent control from industrial or mining activities involving naturally occurring radioactive materials (NORM).
- Emergency response monitoring after radiological incidents.
- Laboratory validation and method harmonization for routine radioactivity testing using liquid scintillation counting.
Who should use this standard
- Analytical laboratories performing radioactivity measurements and accreditation bodies.
- Water utilities and public health authorities responsible for drinking water safety.
- Environmental monitoring agencies and consultants.
- Nuclear and industrial facilities managing radioactive effluents.
- Researchers and developers validating LSC methods for radionuclide analysis.
Related standards
- ISO 13165 series (other parts for complementary methods or radionuclides)
- ISO/IEC Guide 98-3 (evaluation of measurement uncertainty)
- Relevant WHO and national drinking water radioactivity guidance documents
Using EN ISO 13165-1:2024 helps ensure consistent, validated, and reportable results for Radium‑226 in water using LSC, supporting regulatory compliance and public health protection.