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Abstract

THE KINETICS OF FORMATION OF URANIUM-PLUTONIUM NITRIDE PELLETS BY CARBOTHERMIC REDUCTION OF URANIUM- AND PLUTONIUM OXIDES UNDER FLOWING NITROGEN HAS BEEN INVESTIGATED USING THERMOGRAVIMETRIC TECHNIQUES IN THE TEMPERATURE RANGE 1650-1870 K. THE STARTING BLENDS WERE PREPARED FROM POWDER MATERIAL WITH DIFFERENT CHARACTERISTICS, AND CONTAINED ABOUT 1% CARBON IN EXCESS OF THE AMOUNT TO OBTAIN THE STOICHIOMETRIC COMPOSITION. THE REACTIONS INVESTIGATED WERE : (A) THE CARBOTHERMIC SYNTHESIS UNDER NITROGEN OF A LOW CARBON CARBONITRIDE CONTAINING FREE CARBON AND SMALL AMOUNT OF OXYGEN IMPURITY AND (B) THE DECARBURIZATION OF THE CARBONITRIDE UNDER A N(2)-8% H(2) GAS MIXTURE. THE CARBOTHERMIC SYNTHESIS FOLLOWS A FIRST-ORDER RATE EQUATION AND THE VALUE OF THE ACTIVATION ENERGY IS 307 KJ/MOL. THE RATE CONSTANTS OF THE DECARBURIZATION REACTION COULD NOT BE DETERMINED BY GRAVIMETRIC PROCEDURES BECAUSE THE HYDROGENATION OF FREE AND CHEMICALLY BOUND CARBON CAUSED AT THE SAME TIME OPPOSING WEIGHT CHANGES. THIS WORK WAS CARRIED OUT WITHIN THE FRAMEWORK OF THE STUDY FOR THE FABRICATION OF (U, PU)N FUEL USING THE DIRECT PRESSING METHOD.

Additional information

Authors: PAUTASSO G, JRC-KARLSRUHE;RICHTER K, JRC-KARLSRUHE;SARI C JRC-KARLSRUHE, JRC-KARLSRUHE
Bibliographic Reference: JOURNAL OF NUCLEAR MATERIALS, VOL. 158, PP 12-18, 1988
Record Number: 1989126203600 / Last updated on: 1989-04-01
Category: PUBLICATION
Available languages: en
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