Abstracts and Available Papers Presented at the
2002 International RERTR Meeting

THERMALHYDRAULIC ANALYSIS OF URANIUM SILICIDE FUEL ELEMENTS TO BE IRRADIATED AT RA-3 REACTOR WITHIN THE QUALIFICATION PROGRAM

Silvia Halpert – Luis Vázquez

Comisión Nacional de Energía Atómica, Argentina

ABSTRACT

A qualification program of technology and installations to manufacture MTR fuel elements based on uranium silicide disperse in aluminum (U₃Si₂ –Al) is being carried out in CNEA. As a part of this program it is necessary to irradiate fuel elements to know its behavior. In this way two MTR prototypes, named P-06 y P-07, are being irradiated at RA-3 reactor.

There are some differences between P-06 or P-07 and normal fuel elements (ECBE) used at RA-3 reactor: geometric differences, fuel plates number (P-07 has 20 fuel plates, that is one more than ECBE) and a greater mass of U²³⁵ (20 % in the case of P-06 y 50 % for P-07).

Although the presence of P-06 and P-07 in core does not affect its hydraulic characteristics (because the core is mostly composed of ECBEs) the differences in geometry will change coolant velocity between the plates.

Additionally, the quantity of U²³⁵ in P-06 and P-07 changes the cooling requirements. Thus, it was necessary to make a thermal/hydraulic analysis to determine the feasibility of irradiating them with the adequate cooling condition in RA-3 reactor. This work presents the performed analysis. The calculations were performed with TERMIC code.

The analyzed fuel elements can be irradiated if the relation between its maximum heat flux and average heat flux in the core is lower or equal to: 3.5 for the P-06 case and 3.3 for the P-07 case.