| 论文简介 |
The oxidization and coolability characteristics of the particulate Zircaloy debris bed, which is deposited under the
hard debris and through which first vapor penetrates and then water penetrates, are studied in the present paper. In the
vapor penetration experiments, it is found that Zircaloy debris particles are effectively broken into small pieces after
making thick oxidized layer with deep clacks by rapid oxidization under the condition that vapor with 20 cm/s penetrates
for 30 to 70 min at an initial debris bed temperature of 1,030C. It is also confirmed in the water penetration
experiments that the oxidized particle debris bed has potentiality of high coolability when water penetrates through the
fully oxidized particle bed because of a high capillary force originating from those particles with deep cracks on their
surfaces.
Based on the present study, a new scenario for the appearance and disappearance of the hot spot in the TMI-2 accident
is possible. The particulate core-metal debris bed is first heated up by rapid oxidization with heat generation
when vapor can penetrate through the debris bed with porosities. This corresponds to the appearance of the hot spot.
The resultant oxidized particulate debris bed causes a high coolability due to its high capillary force when the water
can touch the debris bed at wet condition. This corresponds to the disappearance of the hot spot. |
(创新港)
