Process for the fabrication of fuel elements designed for high-temperature operation

Claim 1

PROCESS FOR THE FABRICATION OF NUCLEAR REACTOR FUEL ELEMENTS FOR HIGH TEMPERATURE OPERATION COMPRISING THE STEPS OF MOLDING A FULE CORE FROM A PLASTIC PASTE OF A MIXTURE OF A REFRACTORY POWDER HAVING A PARTICLE SIZE UP TO 400 MICRONS, A FISSIONABLE MATERIAL AND A BINDER OF LOW COKING YIELD AND HIGH SWELLING POWER IN THE PRESENCE OF WATER CHEMICALLY COMPATIBLE WITH SAID REFRACTORY POWDER AND IN AMOUNTS FROM 2-5% BY WEIGHT, MOLDING A JACKET OF AT LEAST TWO LAYERS AROUND SAID FUEL CORE FROM A PLASTIC PASTE OF A MIXTURE OF A REFRACTORY POWDER AND A BINDER CHEMICALLY COMPATIBLE WITH SAID REFRACTORY POWDER, SAID LAYERS HAVING A REFRACTORY MATERIAL PARTICLE SIZE FROM 20-100$ AND A THICKNESS OF FROM 1 TO 2 MILLIMETERS AND THEN, AFTER FORMATION OF EACH OF SAID LAYERS, SIMULTANEOUSLY BONDING SAID JACKET TO SAID FUEL CORE AND RENDERING SAID JACKET IMPERMEABLE BY THERMAL CRACKING A GASEOUS HYDROCARBON AT A TEMPERATURE BETWEEN 800* AND 1000*C. IN THE PORES OF SAID FULE COARE AND SAID JACKET FOR ABOUT 300-350 HOURS.