ISO 10703:2021
Water quality — Gamma-ray emitting radionuclides — Test method using high resolution gamma-ray spectrometry
Water quality — Gamma-ray emitting radionuclides — Test method using high resolution gamma-ray spectrometry
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 27
- Дата публикации:
- 24 июня 2021 г.
- Издание:
- ISO IS 10703 edition 3 version 1
- ICS:
- 13.060.60
This document specifies a method for the physical pre-treatment and conditioning of water samples and the determination of the activity concentration of various radionuclides emitting gamma-rays with energies between 40 keV and 2 MeV, by gamma‑ray spectrometry according to the generic test method described in ISO 20042. The method is applicable to test samples of drinking water, rainwater, surface and ground water as well as cooling water, industrial water, domestic and industrial wastewater after proper sampling, sample handling, and test sample preparation (filtration when necessary and taking into account the amount of dissolved material in the water). This method is only applicable to homogeneous samples or samples which are homogeneous via timely filtration. The lowest limit that can be measured without concentration of the sample or by using only passive shield of the detection system is about 5·10-2 Bq/l for e.g. 137Cs.1 The upper limit of the activity corresponds to a dead time of 10 %. Higher dead times may be used but evidence of the accuracy of the dead-time correction is required. Depending on different factors, such as the energy of the gamma-rays, the emission probability per nuclear disintegration, the size and geometry of the sample and the detector, the shielding, the counting time and other experimental parameters, the sample may require to be concentrated by evaporation if activities below 5·10-2 Bq/l need to be measured. However, volatile radionuclides (e.g. radon and radioiodine) can be lost during the source preparation. This method is suitable for application in emergency situations. 1The sample geometry: 3l Marinelli beaker; detector: GE HP N relative efficiency 55 % ; counting time: 18h.
Abstract
Overview
ISO 10703:2021 - Water quality - Gamma-ray emitting radionuclides specifies a standardized test method for measuring the activity concentration of gamma‑ray emitting radionuclides in water using high‑resolution gamma‑ray spectrometry. The method covers sample pre‑treatment and conditioning and applies to drinking water, rainwater, surface and ground water, cooling and industrial water, and domestic/industrial wastewater (after appropriate sampling and handling). The energy range covered is 40 keV to 2 MeV, and the method follows the generic approach in ISO 20042.
Key technical topics and requirements
- Sample preparation and conditioning
- Direct measurement, filtration to obtain homogeneity, evaporation/concentration (with and without iodine retention) where needed.
- Note on volatile radionuclides: radon and radioiodine can be lost during concentration.
- Measurement range and limits
- Typical achievable lower limit without concentration: about 5·10⁻² Bq·L⁻¹ for 137Cs (example: 3 L Marinelli beaker; GE HP N detector, 55% relative efficiency; 18 h counting).
- Upper activity limit tied to detector dead time; default guidance sets 10% dead time (higher acceptable only with validated dead‑time correction).
- Instrumentation and calibration
- High‑resolution detectors (e.g., HPGe), shielding, acquisition electronics (analog/digital), and software.
- Energy and efficiency calibration methods including laboratory reference sources and Monte Carlo efficiency calibration.
- Corrections and data treatment
- Dead time and pulse pile‑up corrections, decay corrections, true coincidence summing, background contributions.
- Uncertainty evaluation, decision threshold, detection limit and coverage intervals per modern ISO approaches.
- Reporting and quality
- Test report requirements, sampling/storage aligned with ISO 5667‑3.
Practical applications
- Routine monitoring of drinking water and environmental waters for natural and anthropogenic gamma emitters.
- Compliance testing for regulatory and WHO guidance levels.
- Emergency and post‑accident monitoring (rapid assessment of contaminated waters).
- Monitoring liquid effluents from nuclear facilities and industrial discharges.
- Wastewater surveillance where radionuclide content is a concern.
Who should use this standard
- Environmental and public‑health laboratories performing radioactivity analyses.
- Radiation protection and emergency response teams.
- Nuclear facility operators and wastewater managers.
- Regulatory agencies and accredited testing bodies requiring standardized gamma spectrometry methods.
Related standards (selection)
- ISO 20042 - Generic gamma spectrometry test method reference
- ISO 5667‑3 - Water sampling - storage and handling
- ISO 11929 series - Detection limits and decision thresholds
- ISO/IEC Guide 98‑3 (GUM) - Uncertainty evaluation
Keywords: ISO 10703:2021, water quality, gamma‑ray spectrometry, high‑resolution, radionuclides, activity concentration, HPGe detector, detection limit, emergency monitoring.
Технические детали
- Технический комитет
- ISO/TC 147/SC 3 - Radioactivity measurements
- SKU
- ISO 10703:2021
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