RADIATION ENHANCED DIFFUSION IN UO-2 AND (U,PU)O-2
The radiation enhanced diffusion (coefficient D*) of 233-U and 238-Pu in UO-2 and (U,Pu)O-2 with 2.5 and 15 % Pu was measured during fission in a nuclear reactor. Normal diffusion sandwiches with a thin tracer layer were used. A radiofrequency furnace allowed the temperatures to be varied between 130 and 1400 degrees C. Neutron fluxes (7x10**12to 1.2 x 10**14n cm**-2s**-1) and irradiation times (56 to 334 h) were also varied to cover ranges of fission rates F between 7 x 10**11 and 6.4 x 10**13f cm**-3s**-1 and of doses F between 4.2 x 10**17 and 3.1 x 10**19f cm**-3. Below +- 1000 degrees C, D* was completely athermal and increased linearly with F. It was described by D* = A x F with A=1.2 x 10**-29 cm**5. A possible temperature dependence was indicated between +- 1000 and 1200 degrees C. The results are explained in terms of thermal and pressure effects of fission spikes and are related to other studies of radiation damage as well as to technologically interesting processes occurring in UO-2 during irradiation.
Bibliographic Reference: RADIATION EFFECTS, VOL. 75 (1983), PP. 317-325
Record Number: 1989122053100 / Last updated on: 1987-01-01
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