Role of potentiometry in assay analysis

The development of zirconium and its alloys for use in nuclear power reactors began in USA in 1948, when it was found that hafnium free zirconium had a much lower neutron absorption cross section than had previously been thought off. Structural material for use in water cooled reactors must possess a combination of high strength corrosion resistance and low neutron capture cross section. Hence to ensure adequate mechanical strength to zirconium components in the reactor core and for dependable corrosion resistance at elevated temperatures and pressurised water environment, zirconium has to be alloyed with certain alloying constituents like chromium, nickel, iron and tin. More recently Zr-2.5% Nb alloy is preferred by virtue of its higher mechanical strength and better sustainability in the reactor environment. That is how zircaloys have become indispensable to present day CANDU type of reactors as structural components and for fuel cladding. Therefore addition of Fe, Ni and Cr provides the greatest corrosion resistance. All the zircaloy hardware required for fuel fabrication like tubing, appendages, end plugs, end plates, as well as core internals like coolant tubes, calandria tubes, garter springs are fabricated in Nuclear Fuel complex, Hyderabad since its inception. The method followed for assaying of chromium in chromium powder offers high accuracy, precision, reliability, speed and simplicity and hence is suitable for routine application