Determination of boron in zirconium-niobium alloys by spectrophotometry

Abstract

Boron doped zirconium-niobium alloy rods are used as neutron reactivity control rods in advanced nuclear reactors. Accurate knowledge about the boron content in this alloy is an essential requirement prior to its usage in nuclear reactors. In view of the refractory nature of the alloy, boron determination in these type of matrices is a challenging task. Also due to non-availability of matrix matched reference materials, direct solid analysis cannot be resorted to. Quantitative dissolution of the matrix without losing any boron followed by its determination is the only alternative. In the present work, Zr-Nb sample was dissolved in (NH₄)₂SO₄ and H₂SO₄ taking care to prevent the loss of boron. Boron was selectively separated employing batch extraction with 10% 2-ethyl hexane 1,3 diol in chloroform and determined spectrophotometrically as B-Curcumin complex. Absorbance was measured at 550 nm. The precision and accuracy of the method is 3%. The absolute detection limit of the method is 12 ng. The method has been evaluated by standard addition method and validated by ICP-AES technique.