|
KMID : 0371819960280040349
|
|
Nuclear Engineering and Technology
1996 Volume.28 No. 4 p.349 ~ p.358
|
|
|
The Leaching Behavior of Unirradiated UO2 Pellets in Wet Storage and Disposal Conditions
|
|
Geun II Park and Hoo Kun Lee
|
|
|
Abstract
|
|
|
|
The leaching behavior of uranium from unirradiated CANDU UO2 fuel pellet in the spent fuel wet storage and disposal conditions has been investigated. A modified IAEA leach test method was used, and then the extent of leaching was monitored by analysis for uranium in the leachant. The leach test has been performed in various leachants(demineralized water and boric acid solution at pH=6, synthetic granite groundwater) for a long-term period of 5.4 years, and the effect of temperature on the leach rate of uranium has been analyzed. The leach rates of uranium at 25?C were dependent on the leachants. Over initial 100 days of leach periods, the leach rate in groundwater was the highest in three leachants and no significant differences of leach rates ore observed in the demineralized oater and boric acid solution. But these leach rates in three leachants around 2,000 days at 25?C appeared to be reached the steady rates in the range of 1~5×10?8 g/cm2 day. The leach rate of uranium in groundwater shooed to be independent of the temperature, but those in both demineralized water and boric acid solution increased with temperature. These results show that the leaching behavior of uranium from UO2 fuel in both the demineralized water ann boric acid may be controlled tv the surface oxidative.dissolution reaction of UO2 and the leach rate of uranium in groundwater at room temperature could mainly be controlled by the complex reaction of dissolved uranyl ions with carbonate ions and no variation of leach rate of UO2 in groundwater with temperature may be due to the local deposition of passivating uranyl phases on the surface.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|