ISO 19461-1:2018 PDF

Overview

ISO 19461-1:2018 - Radiological protection - Measurement for the clearance of waste contaminated with radioisotopes for medical application - Part 1: Measurement of radioactivity - specifies a method for measuring radioactivity and determining minimum storage periods for radioactive wastes generated by medical use of radioisotopes. The standard uses counting measurements with detectors and decay correction of initial activity concentration to verify wastes meet a designated clearance level. It supports self-clearance by medical facilities and can be used by testing laboratories, waste disposal operators, and regulators. Note: this Part 1 method does not apply to pure beta emitters or alpha emitters with low-energy gamma rays.

Key topics

• Measurement method: Counting measurements using detectors with decay correction to estimate initial activity concentration and evaluate decay to clearance.
• Storage-period determination: Procedures to calculate minimum storage durations so waste decays below the applicable clearance level.
• Controls and requirements: Pre-storage controls, measurement before storage, storage container and disposal method guidance.
• Uncertainty and quality control: Requirements for evaluating measurement uncertainty, documentation, reporting and ongoing quality assurance.
• Scope limitations: Explicit exclusion of pure beta-emitting nuclides and alpha emitters with low-energy gamma rays.
• Supporting materials: Annexes provide example procedures and sample measurement results to aid implementation.

Applications

Who uses ISO 19461-1:2018 and how:

• Medical facilities (hospitals, nuclear medicine departments): To implement self-clearance processes for short-lived radioisotope waste and to calculate storage time before non-radioactive disposal.
• Testing laboratories: To perform traceable radioactivity measurements and report results consistent with clearance verification.
• Radioactive waste disposal operators: To accept, verify and manage decay-storage of medical radioactive wastes.
• Regulatory bodies: For guidance on acceptable measurement methods, documentation and demonstrating compliance with clearance criteria.

Practical benefits include standardized detector-based measurement procedures, traceable documentation of decay-based clearance, and improved confidence that disposed materials meet public dose and environmental protection objectives.

Related standards

• ISO 19461 series (other parts) - for broader guidance across the clearance workflow.
• International Atomic Energy Agency (IAEA) guidance (referenced in the standard) - for dose- and concentration-based clearance criteria and complementary approaches.

Keywords: ISO 19461-1:2018, radiological protection, measurement for the clearance of waste, radioactivity measurement, medical radioisotopes, decay correction, clearance level, self-clearance, radioactive waste disposal.