Tritium Measurement Technique Using “In-Bed” Calorimetry

Abstract

One of the new technologies that has been introduced to the Savannah River Site (SRS) is the production scale use of metal hydride technology to store, pump, and compress hydrogen isotopes. For tritium stored in metal hydride storage beds, a unique relationship does not exist between the amount of tritium in the bed and the pressure-volume-temperature properties of the hydride material. Determining the amount of tritium in a hydride bed after desorbing the contents of the bed to a tank and performing pressure, volume, temperature, and composition (PVTC) measurements is not practical due to long desorption/absorption times and the inability to remove tritium ``heels`` from the metal hydride materials under normal processing conditions. To eliminate the need to remove tritium from hydride storage beds for measurement purposes, and ``in-bed`` tritium calorimetric measurement technique has been developed. The steady-state temperature rise of a gas stream flowing through a jacketed metal hydride storage bed is measured and correlated with power input to electric heaters used to simulate the radiolytic power generated by the decay of tritium to {sup 3}He. Temperature rise results for prototype metal hydride storage beds and the effects of using different gases in the bed are shown. Linear regression more » results shows that for 95% confidence intervals, temperature rise measurements can be obtained in 14 hours and have an accuracy of {plus_minus}1.6% of a tritium filled hydride storage bed. « less