ISO 18589-7:2025

Overview

ISO 18589-7:2025 - Measurement of radioactivity in the environment - Soil - Part 7 specifies methods for in situ gamma spectrometry to identify and quantify gamma-emitting radionuclides in soil. The standard covers the use of portable systems equipped with germanium or scintillation detectors for rapid, on-site assessment of artificial and natural radionuclide activity deposited on or present in surface and near-surface soil layers. It supports routine environmental surveillance, emergency response, remedial planning, decommissioning and clearance activities, and complements laboratory soil analysis (see ISO 18589-3).

Key technical topics and requirements

• Equipment and detector systems: requirements for portable in situ spectrometry systems, germanium and scintillation detectors, collimated detectors, assembly jigs and pulse-processing electronics.
• Field-of-view and geometry: evaluation of detector field‑of‑view and geometry factors for different radionuclide distributions in soil.
• Calibration methods: combined calibration approach including intrinsic detector efficiency, geometry factors, angular correction factors and numerical calibration procedures.
• Measurement principles and uncertainties: guidance on measurement method, estimation and propagation of standard uncertainty, and limits such as decision threshold and detection limit.
• Quality assurance and control (QA/QC): instrument and method verification, periodic quality checks, documentation and standard operating procedures to ensure reliable in situ gamma spectrometry results.
• Data expression and reporting: calculation of activity per unit surface area or mass, conversion to ambient dose rates, and content of the required test report.
• Informative annexes: supporting material such as field-of-view charts, conversion factors to ambient dose rates, attenuation/mass attenuation data, and worked examples for uncertainty and detection limit calculations.

Practical applications and users

ISO 18589-7:2025 is intended for professionals and organizations involved in:

• Environmental monitoring and radiation surveillance around nuclear installations.
• Emergency and incident response teams performing rapid assessment after a nuclear accident.
• Remediation and decommissioning planners assessing surface contamination and planning cleanup.
• Waste management and disposal operations assessing airborne or surface radionuclide presence.
• Radiation protection specialists, survey technicians and laboratories pairing in situ data with ISO 18589-3 laboratory analyses.

Benefits include fast, cost-effective mapping of large areas, immediate dose-rate estimation, and support for rapid decision-making during routine monitoring and emergency response.

Related standards

• ISO 18589 series (see ISO 18589-3 for laboratory radionuclide measurements in soil)
• Other parts of the ISO 18589 family provide complementary methods and guidance for environmental radioactivity measurement and reporting.