Overview
EN ISO 9697:2019 - Water quality - Gross beta activity - Test method using thick source (ISO 9697:2018) specifies a laboratory method for measuring gross beta activity concentration in non-saline waters (including raw and drinking waters) using a thick-source counting technique. The method targets non‑volatile beta-emitting radionuclides with maximum beta energies ≈ 0.3 MeV or higher. Low-energy beta emitters (for example 3H, 210Pb, 14C) and some volatile radionuclides (radon, radioiodine) may not be fully quantified by this method. The document is adopted by CEN and supersedes EN ISO 9697:2017.
Key topics and technical requirements
- Scope and applicability: Designed for non-saline matrices; applicability depends on total soluble salts and counter performance (background count rate and counting efficiency). Laboratories must confirm method suitability for their samples.
- Principle and technique: Thick-source preparation followed by beta counting; emphasizes control of interferences and radionuclide disequilibrium.
- Analytical stages covered:
- Sampling and pre-treatment
- Concentration and sulfation stages
- Ignition and thick-source preparation
- Measurement and background determination
- Calibration source preparation and counting efficiency
- Performance metrics: Procedures for calculating activity concentration, standard uncertainty, decision threshold, detection limit, and confidence limits.
- Quality control: Source contamination checks, potential radionuclide disequilibrium, and recommended documentation for test reports.
- Traceability and uncertainty: Guidance to align results with ISO/IEC Guide 98‑3 and relevant water-quality guidance.
Applications and users
EN ISO 9697:2019 is intended for:
- Environmental and drinking-water testing laboratories
- Water utilities and public health agencies monitoring radioactivity
- Nuclear facilities and operators assessing liquid effluents
- Regulatory bodies requiring compliance verification with national or WHO guidance levels
Typical uses:
- Routine monitoring of gross beta in drinking water and raw water supplies
- Screening measurements during emergency response or planned releases
- Pre-discharge checks of wastewaters and liquid effluents
Related standards and references
- ISO 5667-20 (sampling guidance for radioactivity in water) - referenced for sampling/uncertainty context
- ISO/IEC Guide 98‑3 (GUM) - for uncertainty evaluation
- WHO drinking-water guidance levels for gross beta/gross alpha (context for action levels)
- EN ISO 9697:2019 replaces EN ISO 9697:2017 (minor revisions; title and formula corrections)
For laboratories and practitioners, EN ISO 9697:2019 provides a standardized, traceable approach to gross beta activity measurement using the thick-source technique, enabling reliable screening and compliance assessment in non-saline water quality monitoring.
