ISO 22875:2017 pdf download

ISO 22875:2017 pdf download.Nuclear energy — Determination of chlorine and fluorine in uranium dioxide powder and sintered pellets
1 Scope
This document describes a method for determining chlorine and fluorine in uranium dioxide powder and sintered pellets. It is applicable for the measurement of samples with a mass fraction of chlorine from 5 µg/g to 500 µg/g and with a mass fraction of fluorine from 2 µg/g to 500 µg/g.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 9892:1992, Uranium metal, uranium dioxide powder and pellets, and uranyl nitrate solutions —Determination of fluorine content — Fluoride ion selective electrode method
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
4 Principle
The samples are pyrohydrolysed at 850 °C to 1 000 °C in a tubular furnace with steam or moist air or moist oxygen heated to the same temperature. Chlorine and fluorine are trapped as halogenated acids and entrained in an aqueous solution.
Two measurement methods may be used to measure the chlorine and fluorine ions:
a) liquid ion chromatography;
b) ion-selective electrode.
5 Reagents
Use reagents of recognized analytical grade.
5.1 Water, complying with at least grade 1 in accordance with ISO 3696.
5.2 Anhydrous sodium chloride (NaCl).
5.3 Anhydrous sodium fluoride (NaF).
5.4 Sodium carbonate (Na 2 CO 3 ).
5.5 Anhydrous sodium bicarbonate (NaHCO 3 ).
5.6 Glacial acetic acid (CH 3 COOH), ρ(CH 3 COOH) = 1,06 g/ml.
5.7 Potassium acetate (CH 3 COOK).
5.8 Concentrated eluent solution, c(Na 2 CO 3 ) = 0,018 mol/l and c(NaHCO 3 ) = 0,017 mol/l.
Dissolve 1,908 g of Na 2 CO 3 (5.4) and 1,428 g of NaHCO 3 (5.5) in water (5.1). Pour into a 1 l volumetric flask. Dilute to 1 l with water (5.1). Homogenize.
Instead of Na 2 CO 3 , the eluent solution can also be NaOH solution for instance, c(NaOH) = 0,2 mol/l. This solution can be prepared by dilution in water (5.1) of concentrated sodium hydroxide solution (5.22).
Depending of the sample to be measured and the column used, Na 2 CO 3 or NaOH is used.
5.9 Standard eluent solution, add 100 ml of concentrated eluent solution (5.8) to a 1 l volumetric flask.
Dilute to 1 l with water (5.1). Homogenize.
5.10 Make-up eluent solution, c(Na 2 CO 3 ) = 0,09 mol/l and c(NaHCO 3 ) = 0,085 mol/l.
Dissolve 9,540 g of Na 2 CO 3 (5.4) and 7,140 g of NaHCO 3 (5.5) in water (5.1). Pour into a 1 l volumetric flask. Dilute to 1 l with water (5.1). Homogenize.