Neutron flux measurements in a core formed by Low Enrichment Uranium (LEU), assembly fuel

The RECH-1 reactor started operation with highly enriches fuel (80% 235U); nevertheless, due to international agreements, the next charge ought to consider a reduction in the enrichment level, from 45 % to 20 % in 235U, to reach, later on, the accepted international level of 19.75 %. The RECH-1 enrichment conversion process has been gradual; is to say, it went from high to medium through mixed cores and the same strategy is being used to go from medium to low enrichment. With the purpose of making characterization measurements of a core formed only with low enrichment, and so to compare results with equivalent cores using MHU or HEU, it was decided to shape a core entirely conformed with by 32 new low enrichment, made at the CCHEN's Chilean Fuel Fabrication Plant (PEC). Amongst all measurements done, it can be found the thermal, epithermal and fast neutron flux profiles in positions of interest, making use for it Au and In activation probes. The main object of this paper is to show the experimental results obtained, which, just in comparison way, will be contracted to values achieved using MCNP neutron calculations, based in Montecarlo's theory (author)