Yh. Koo et al., AN ANALYSIS METHOD FOR THE FUEL-ROD GAP INVENTORY OF UNSTABLE FISSION-PRODUCTS DURING STEADY-STATE OPERATION, Journal of nuclear materials, 209(1), 1994, pp. 62-78
An analysis method was developed to predict the equilibrium inventory
of unstable fission products present in the fuel-to-cladding gap of fu
el elements during steady-state operation. With the shape of grain tre
ated as tetrakaidecahedron (TKD), the interlinked fraction of fission
gas bubbles to open space at grain corners was determined with use of
the Monte Carlo technique and the model of White and Tucker. The metho
d was applied to calculate the gap inventory of unstable fission produ
cts for CONTACT experiments and FIO series tests. Bubble interlinkage
at grain corners was shown to be the rate-controlling step in the rele
ase of fission products from the matrix to the open space. Comparison
shows that the method reasonably well predicts the gap inventory in th
e temperature and burnup ranges investigated.