GB/T 15221-2025Analytical method for cobalt-60 in water (English PDF)

1 Scope

This document describes the analytical method for cobalt-60 in water, including the principle, reagents or materials, instruments and equipment, samples, experimental procedures, and experimental data.

Processing, precision, quality assurance and control, etc.

This document applies to the analysis of cobalt-60 in surface water, groundwater, drinking water, and liquid effluents from nuclear facilities.

Under typical conditions, the detection limit of the low-background alpha/beta meter measurement method is 9.9 mBq/L, and the detection limit of the liquid scintillation counter measurement method is...

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 10259 Liquid Scintillation Counter

GB/T 11682 Low-background alpha and/or beta measuring instruments

GB 12379 Regulations for Environmental Nuclear Radiation Monitoring

HJ61 Technical Specification for Radiation Environment Monitoring

3 Terms and Definitions

This document does not contain any terms or definitions that need to be defined.

4 Principles

A cobalt carrier was added to the water sample, and cobalt-60 was concentrated as a hydroxide precipitate. Cobalt was then complexed with ammonia, allowing it to react with nuclides such as iron, manganese, ruthenium, and zirconium.

Separation. Cobalt was further purified by passing it through an anion exchange resin column. The eluent was collected, and the resorption was determined using atomic absorption spectrophotometry or gravimetric analysis.

Yield. When measuring with a low-background alpha/beta meter, the desorption solution was evaporated to dryness, dissolved in electrolyte buffer, and then measured after electrodeposition to prepare the source.

Alternatively, when using a liquid scintillation counter for measurement, evaporate the desorption liquid to dryness, dissolve it in nitric acid solution, add the scintillation liquid, mix thoroughly, and then measure.

5 Reagents or materials

Unless otherwise specified, all analytical reagents conforming to national standards were used in the analysis, and the water used in the tests was freshly prepared deionized water or distilled water.

Distilled water.