Process for rapid processing of SiC and graphitic matrix triso-bearing pebble fuels
A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.
1. A nuclear fuel pebble comprising:
an inner fuel pebble including fuel particles microencapsulated within a fully ceramic matrix; and
a non-fueled matrix ceramic surrounding the inner fuel pebble.
2. The nuclear fuel pebble according to claim 1 , wherein the fuel particles are tristructural-isotropic fuel particles (TRISO).
3. The nuclear fuel pebble according to claim 1 , wherein the fully ceramic matrix comprises graphite or silicon carbide.
4. The nuclear fuel pebble according to claim 1 , wherein the non-fueled matrix ceramic comprises graphite.
5. The nuclear fuel pebble according to claim 4 , wherein the non-fueled matrix ceramic further comprises phenolic or other resin binder.
6. The nuclear fuel pebble according to claim 1 , wherein the non-fueled matrix ceramic comprises silicon carbide.
7. The nuclear fuel pebble according to claim 6 , wherein the non-fueled matrix ceramic further comprises a rare-earth oxide neutronic poison selected from the group consisting of Gd 2 O 3 , Er 2 O 3 , Dy 2 O 3 , and Eu 2 O 3 , and combinations thereof.
8. The nuclear fuel pebble according to claim 6 , wherein the non-fueled matrix ceramic further comprises sintering additives selected from the group consisting of Al 2 O 3 and Y 2 O 3 and combinations thereof.
9. The nuclear fuel pebble according to claim 1 , wherein the inner fuel pebble is sintered using direct current sintering prior to being surrounded by the non-fueled matrix ceramic.
10. The nuclear fuel pebble according to claim 9 , wherein the nuclear fuel pebble is sintered using direct current sintering on the already sintered inner fuel pebble surrounded by the non-fueled matrix ceramic.