Boiling And Fragmentation Behavior During Fuel Sodium Interactions
Abbreviated Journal Title
Nucl. Eng. Des.
Nuclear Science & Technology
A selection of the results and subsequent analysis of molten fuel-sodium interaction experiments conducted within the JRC BETULLA I and II facilities are reported.
The fuels were copper and stainless steel, at initial temperatures far above their melting points; or urania and alumina, initially at their melting points. For each test, the molten fuel masses were in the lower kilogram range and the subcooled pool mass was either 160 or 4 kg. The sodium pool was instrumented to continually monitor the system temperature and pressure. Post-test examination results of the fragmented fuel debris sizes, shape and crystalline structure are given.
The results of this study suggest the following:
- Transition boiling is the dominant boiling mode for the tested fuels in subcooled sodium.
- Two fragmentation mechanisms, vapour bubble formation/collapse and thermal stress shrinkage cracking prevailed for the oxide fuels. This was evidenced by the presence of both smooth and fractured particulate. In contrast, all metal fuel debris was smooth, suggesting fragmentation by the vapour bubble formation/collapse mechanism only during the molten state.
- For each test, there was no evidence of an energetic fuel-coolant interaction.
Nuclear Engineering and Design
Schins, H. and Gunnerson, F. S., "Boiling And Fragmentation Behavior During Fuel Sodium Interactions" (1986). Faculty Bibliography 1980s. 535.