Comparison of some measurements in the Greek Research Reactor-1 (GRR-1) with 20% and 93% enriched uranium fuel elements

Experimental results of the core performance of the GRR-1 with 20% and 93% enriched 235U are compared. In particular, the rod worth, the flux distribution (axial and radial), the temperature, and the void effects are analyzed and compared for the two cores. The experimental results are in good agreement with benchmark calculations for this reactor and for other similar reactors. Although the fuel elements of the two cores do not have the same number of plates, the results are of special significance, since they present the only experimental comparative work known so far on the core conversion problem from the use of highly enriched uranium to the use of low enriched uranium fuels. (author)