Water Sorption and Gamma Radiolysis Studies for Uranium Oxides
- Oak Ridge National Laboratory (United States)
Experiments have been performed in our laboratory on water sorption and radiolysis for uranium oxides. For the water sorption experiments, uranium oxide samples were prepared and exposed to known levels of humidity to establish the water uptake rate. Subsequently, the amount of water removed was studied by heating samples in an oven at fixed temperatures and by differential thermal analysis/thermogravimetric analysis. It was demonstrated that heating at 650 deg. C adequately removes all moisture from the samples. Uranium-238 oxides were irradiated in a {sup 60}Co source and in the high-gamma-radiation fields provided by spent nuclear fuel elements of the High Flux Isotope Reactor. For hydrated samples of UO{sub 3}, the primary gas produced was H{sub 2}; however, the maximum pressure increase reached a steady-state value of {approx}500 torr (10 psi). This H{sub 2} production appears to be a function of the dose and the amount of water present. Oxygen in the hydrated UO{sub 3} sample atmosphere was typically depleted, and no significant pressure rise was observed. Heat treatment of the UO{sub 3}.xH{sub 2}O at 650 deg. C results in conversion to U{sub 3}O{sub 8} and eliminates the H{sub 2} production. For all of the U{sub 3}O{sub 8} samples loaded in air and irradiated with gamma radiation, a pressure decrease was seen and little, if any, H{sub 2} was produced - even for samples with up to 9 wt% moisture content. Hence, these results demonstrated that the efforts to remove trace moisture from U{sub 3}O{sub 8} are not necessary to avoid pressurization of stored uranium oxides caused by gamma-induced radiolysis. In fact, this system can tolerate several percent of sorbed moisture.
- OSTI ID:
- 20840213
- Journal Information:
- Nuclear Technology, Vol. 147, Issue 2; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 0029-5450
- Country of Publication:
- United States
- Language:
- English
Similar Records
HOMOGENEOUS REACTOR PROGRAM QUARTERLY PROGRESS REPORT FOR PERIOD ENDING JANUARY 31, 1960
PROGRESS RELATING TO CIVILIAN APPLICATIONS DURING DECEMBER, 1958
Related Subjects
COBALT 60
DIFFERENTIAL THERMAL ANALYSIS
GAMMA RADIATION
HEAT TREATMENTS
HFIR REACTOR
HUMIDITY
HYDROGEN
IRRADIATION
OXYGEN
PRESSURIZATION
RADIATION DOSES
RADIOLYSIS
SORPTION
SPENT FUELS
STEADY-STATE CONDITIONS
THERMAL GRAVIMETRIC ANALYSIS
URANIUM 238
URANIUM OXIDES U3O8
URANIUM TRIOXIDE
WATER