Vapor Pressure of Hypostoichiometric Urania as a Function of Composition

Abstract

The vapor pressure of hypostoichiometric urania was measured as a function of temperature for a series of compositions. The data were obtained by a n entrainment technique in which weight loss of a specimen vaporizing at high temperatures in a stream of carrier gas is followed continuously with a recording thermobalance. Use of suitable atmospheres produced constant vaporizing compositions which vaporized pseudocongruently. Equations obtained for the vapor pressure are :59,100 f . 1000UOl 88 In Pdv (atm) = 15.2 =k 0.4 -____-___

Thermodynamics of the O–U system. IV – Critical assessment of chemical potentials in the U–UO2.01 composition range

“…Although quoted in Table 3 as a determination according to the transpiration method, the Szwarc and Latta [49] work cannot be retained for different reasons:…”

“…For pyrometric measurements [45][46][47][48][49][50][51], the stability of the temperature control added to the pyrometric readings and necessary calibration procedures lead to dT $ ±15 K. For W/Re thermocouples [52], we would prefer to increase slightly the estimates of the authors up to dT = ±10 K.…”

High‐temperature mass spectrometric study of thermodynamic properties in the UO2–ZrO2 system

“…As was shown earlier, 21–33,35–41 UO 2 vaporizes predominantly according to the following equations: where square brackets correspond to the condensed phase and parentheses correspond to the gaseous phase in these and further equations.…”

“…The vaporization processes and thermodynamic properties of the pure oxides UO 2 and ZrO 2 were studied in detail in a series of publications, for example, in Refs 21–41 . and Refs 42–47 .…”

“…The available information on the experimental studies of the UO 2 vaporization processes 21–33,35–41 is summarized in Table 1.…”