OXYGEN POTENTIAL MEASUREMENTS IN IRRADIATED MIXED OXIDE FUEL
In an irradiated (U,Pu)O-(2-x) fuel, radial oxygen redistribution occurs within the temperature gradient. Electromotive force measurements on drillings from different radial positions of a quenched pin show that the shape of the O/M profile is not in agreement with that expected from models and theory. Previous determinations by other authors using electron microprobe or X-ray measurements, however, yield profiles with shapes similar to that observed here. These profiles are characterized by a steep decrease in O/M in the center of the fuel. A transient O/M redistribution model was established yielding time constants for redistribution during cooling. The numerical cases calculated show that the quenching procedure does not affect the O/M profile. Though each of the above three techniques used to experimentally determine O/M profiles on irradiated oxide pins has its shortcomings, the totality of the results is suggested to contain enough evidence to rediscuss and reconsider the basic assumptions and mechanisms of oxygen redistribution in (U,Pu)O-2 fuels.
Bibliographic Reference: JOURNAL OF NUCLEAR MATERIALS, VOL. 124 (1984), PP. 44-55
Record Number: 1989123013800 / Last updated on: 1987-01-01
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