EQUATION OF STATE OF URANIUM OXIDE
The total and partial pressures over liquid UO-2 have been measured and calculated up to 5000 degrees K. A review of previous work is given. The equation of state of UO-2 as the main constituent of the fast breeder oxide fuel is required up to at least 5000 degrees K in order to estimate the energy release in a loss of flow (LOF) driven hypothetical core disruptive accident (HCDA) of the liquid metal fast breeder reactor (LMFBR). Two models, a macroscopic mixture model and a microscopic defect model have been developed to determine the oxygen potential of UO-2.00 up to 5000 degrees K. A combination of mass spectrometric, Langmuir probe and high tension diode studies, applied for the first time to the laser vaporization process, revealed large quantities of ions emitted directly from the surface, and resolve previous discrepancies between measured and calculated vapour pressures by an enhanced rate of evaporation due to ion emission. As shown theoretically intrinsic ion emission can contribute to the net evaporation rate only if the resulting positive space charge can be neutralized. It is proposed that this can be accomplished by the presence of hot electrons in the plasma.
Bibliographic Reference: SYMPOSIUM ON THERMODYNAMICS OF NUCLEAR MATERIALS AT THE IUPAC CONFERENCE ON CHEMICAL THERMODYNAMICS, HAMILTON (CANADA), AUG. 13-17, 1984 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31838 ORA
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Record Number: 1989123025000 / Last updated on: 1987-01-01
Available languages: en