METHOD FOR MEASURING CONCENTRATIONS OF IODINE-CONTAINING SUBSTANCES IN PROCESS LIQUIDS FORMED DURING SPENT NUCLEAR FUEL RECYCLING Russian patent published in 2012 - IPC G01N21/31 

FIELD: absorption spectroscopy.

SUBSTANCE: method can be used for studying and analysing materials, liquid solutions in particular. It can be used to detect iodine in liquid phases during spent nuclear fuel recycling at radiochemical plants. The concentration measurement of four iodine-containing substances (I², I^-, IO₃ ^- and I₃ ^-) with the presence of uranyl in the analysed solution is carried out by repeated of simultaneous measurement of analysed solution radiation absorption rate in five wave lengths. If uranyl concentration is less than 1,5·10¹⁷ cm^-3, λ₁ is kept within the wave length range of 199,8-200,2 nm, λ₂ ranges from 211,8 to 212,2 nm, λ₃ ranges from 225,8 to 226,2 nm. If uranyl concentration ranges from 1,5·10¹⁷ cm^-3 to 1,9·10¹⁹ cm^-3, λ₁ ranges from 199,8 nm to 200,2 nm, λ₂ ranges from 206,8 nm to 207,2 nm, λ₃ ranges from 212,8 nm to 213,2 nm. If uranyl concentration exceeds 1.9·10¹⁹ cm^-3, λ₁ ranges from 203,8 nm to 204,2 nm, λ₂ ranges from 205,8 nm to 206,2 nm, λ₃ ranges from 206,8 to 207,2 nm. If uranyl concentration is less than 5,5·10¹⁷ cm^-3, λ₄ ranges from 287,8 nm to 288,2 nm. If uranyl concentration ranges from 5,5·10¹⁷ cm^-3 to 2,6·10¹⁹ cm^-3, λ₄ ranges from 355,8 to 356,2 nm. If uranyl concentration ranges exceeds 2,6·10¹⁹ cm^-3, λ₄ ranges from 364,8 nm to 365,2 nm, λ₅ ranges from 500 to 700 nm.

EFFECT: measurement accuracy increase.

3 dwg, 2 tbl