GB/T 11844-2015Determination of fluorine and chlorine in uranium dioxide powder and pellets -- Pyrohydrolysis ion-selective electrode method (English PDF)

Foreword

This standard was drafted in accordance with GB/T 1.1-2009 given rules.

This standard replaces GB 11844-1989 "uranium dioxide powder and pellets - Determination of fluorine high temperature hydrolysis - ion selective electrode method" and GB/T 13369-1992 "uranium dioxide powder and pellets - Determination of chlorine in high temperature hydrolysis - ion selective electrode method" and GB 11844-1989 and GB/T 13369-1992, compared the main technical changes are as follows.

--- Modify the sample size and measurement range;

--- Modify the standard curve drawing content;

--- Modified high temperature hydrolysis process parameters;

--- Modify the GB 11844-1989 and GB/T 13369-1992 precision.

This standard uses redrafted Law Amendment uses ISO 22875:2008 "Nuclear testing uranium dioxide powder and sintered pellets of CFCs set".

This standard and ISO 22875:2008, compared with more adjustment in the structure, listed in Appendix A of this standard and ISO 22875:2008 the reg number control list.

This standard and ISO 22875:2008 technical differences exist compared to the terms of these differences has been involved through its outer margin bits Opposing vertical single line (-) were marked, Appendix B gives a list of corresponding technical differences and their causes.

This standard and ISO 22875:2008 compared also made the following editorial changes.

--- Change in name;

--- Increase the informative Appendix C.

The standard proposed by China National Nuclear Corporation.

This standard by the National Standardization Technical Committee on Nuclear Energy (SAC/TC58) centralized.

This standard was drafted. China Jianzhong Nuclear Fuel Limited.

1 Scope

This standard specifies the determination of uranium dioxide powders and pellets by fluorine, chlorine feed method, reagents, instruments and equipment, sample analysis step junction If the calculation and precision of the method.

This standard applies dioxide powder and fluorine, chlorine measured uranium pellets that when a sample in the range of 0.5g ~ 5.0g, the measurement range of the fluorine 1µg/g ~ 400µg/g, chlorine measurement range 2µg/g ~ 200µg/g. The absorbing solution in the presence of impurity ions Al3 not more than 16µg, Ca2 no more than 10µg, Fe3 not more than 10µg, when Mg2 not more than 22µg, does not affect the determination of fluoride.

2 Method summary

Sample in a quartz reactor tube 900 °C ~ 1000 °C, the pass into the air stream containing water vapor at high temperature hydrolysis, fluorine, chlorine, fluorine, respectively Hydrogen, chloride forms evaporate and is absorbing buffer solution, ion selective electrode with fluoride, chloride ion selective electrode.

3 Reagents

Unless otherwise indicated, all using the national standard or professional standard, superior grade pure reagents, analysis of water should comply with the electrical conductivity (25 °C) is not greater than 0.10mS/m.