Hydrogen analysis of zircaloy tube used in nuclear power station using laser plasma technique

Abstract

It is shown that remarkable improvements essential to a quantitative spectrochemical analysis of hydrogen emissions from the zircaloy samples were achieved when the low-pressure surrounding air used in the previous experiment of Nd-YAG laser-induced shockwave plasma was replaced by an inert gas. Using the high-purity (99.999%) nitrogen gas at 1.5 Torr, a linear calibration curve of the HI 656.2 nm emission line was obtained with a zero intercept from the zircaloy samples prepared with various hydrogen concentrations. Further, when the surrounding nitrogen gas was replaced by a helium gas, more than an order of magnitude enhancement was obtained on the signal-to-noise ratio, yielding a detection limit of less than 5 ppm.