EXPERIMENTAL STUDIES OF TRANSIENT EFFECTS IN FAST REACTOR FUELS. SERIES III. PRE-IRRADIATED MIXED OXIDE (PuO$sub 2$-UO$sub 2$) IRRADIATIONS. INTERIM REPORT. STEADY-STATE IRRADIATIONS

Transient Overpower Irradiation of Axially-Restrained, Zero-Burnup, Fast Reactor Fuel Specimens.

“…As a result of this decrease in local energy source, thermocouple No. 6 registered'significantly below the equilibrium level predicted by the intact geometry calculations (figure [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. These results are similar to the response of corresponding thermocouples in specimen C4B (figures 3-11 and 3-12).…”

“…10; see figure [3][4][5][6][7][8][9]. An examination of the radial fuel and cladding temperature histories (see figure [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] indicates that the failure occurred relatively early in the development of the molten fuel core and well before attainment of peak fuel temperatures at ^^3.6 seconds. However, the time of failure does coincide with the maximum radial extent of the fuel-melt boundary and the peak cladding temperature.…”

“…It appears from the response of thermocouple No. 9 (figure [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] that failure occurred at 3.1 to 3.2 seconds into the transient. The response of thermocouple No.…”