Abstracts and Available Papers Presented at the
1997 International RERTR Meeting

U₃Si₂ FUEL DEVELOPMENT AT THE CHILEAN COMMISSION
FOR NUCLEAR ENERGY

H. Contreras, J. Marin, J. Lisboa, J. C. Chavez, L. Olivares

Fuel Fabrication Plant, Nuclear Material Department
Chilean Commission for Nuclear Energy

SUMMARY

The development of LEU Fuel Elements based on uranium silicide, u₃si₂, at the Chilean Commission for Nuclear Energy, CCHEN, is presented in this report².

This development begun with the research project, "Development of Uranium Silicide for use in High Density Nuclear Fuels ", carried out between 1993 and 1994. This research involved induction melting u₃si₂ synthesis, the u₃si₂ comminution to powder form, and finally ended with the fabrication of u₃si₂ - Al m1niplates. At this first stage, the results achieved were a fully characterized u₃si₂ powder that complied with international fabrication standards and a DTA study of the U₃Si₂ - Al interaction in the rolling temperature range used for the miniplates fabrication.

In 1994, the decision to convert the RECH-1 Chilean research reactor to LEU fuel and that this fuel had to be fabricated in Chile, was made. At this second stage, a 3 year program resulting in the fabrication of 50 LEU u₃si₂ - Al fuel elements for the RECH-1 reactor was started. A summary of the work done during 1995 and 1996 is presented. This work involved different areas covering from raw materials acquisition, basic design of the LEU fuel element, fabrication facility implementation, up to nuclear safety assessments and licensing of the proposed fabrication process .

Finally the results of a fabrication run of 5 fuel elements with natural u₃si₂ are presented. This permitted to test the systems and to check all the operational procedures. Two of these elements were de assembled with the purpose of evaluation and inspection. The fuel elements complied with the established specifications. A direct result of this fabrication was a field tested revision of all operational and fabrication procedures and besides, the final revision to the specifications for the proposed RECH-1, fuel element. Having completed all the required phases, it rests only to proceed to the fabrication of the real LEU fuel elements.

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