Operation of a tritium glovebox clean-up system using zirconium manganese ironand zirconium two iron metal getters

摘要

A metal hydride-based tritium clean-up system has been successfully operated formore than four years on an 11 m(sup 3) helium/nitrogen glovebox which was used for handling metal tritide powders. The clean-up system consists of two beds: (1) a Zr-Mn-Fe (in a 10% by weight Al binder, SAES ST909) bed operating at 675 C followed by (2) a Zr(sub 2)Fe (SAES ST198) bed operating at 250 C. The Zr-Mn-Fe bed serves to condition the gas stream by cracking hydrogenous impurities (such as H(sub 2)O and hydrocarbons) and absorbing oxygen and carbon. The Zr(sub 2)Fe bed absorbs the hydrogen isotopes from the flowing stream by forming a solid hydride compound. These beds contain 3 kilograms of Zr(sub 2)Fe and have been loaded routinely with 230-250 STP liters of hydrogen isotopes in earlier trials. The Zr-Mn-Fe alloy exhibits an anomaly during activation, namely an exotherm upon initial exposure to nitrogen. The purpose of this work is to better understand this reaction. Nitrogen absorption studies were done in order to quantify the nitrogen taken up by the getter and to characterize the reaction kinetics. In addition, ST909 phases before and after the reaction were studied with x-ray diffraction.