| Title |
Study on the Thermal Densification of UO2 Pellets |
| Authors |
이규암(K . A . Lee); 박원구(W . K . Park); 이종남(J . N . Lee) |
| Abstract |
The thermal densification of the sintered UO₂ pellets has been investigated by resintering of them in the terms of variations of pore size and pore size distribution. The pore size and its distribution of presintered pellets were controlled by the addition of 1 weight percentage polyethylene glycol sized in the range of 40-125㎛ as a volatile pore former. The density of the pellets were in the range of 92 to 96% of theoretical density. A review of resintering experiments at 1600℃ for 10 hours in the 98.5 v/o N₂-1.5 v/o H₂ mixed gas indicated that the pellet containing large pores with diameter of 40㎛ had the lowest fractional density change of 6.0×10^(-3), while that of 12.34×10^(-3) had been revealed in the pellet containing finer pores than 2㎛. The observations led to the conclusion that high thermal stability was achieved by forming large pores of around 40㎛ in the pellets and high densification was induced by small pores approximately less than 2㎛. |