%A"Cerles, J M" %D1973 %I; CEA Saclay, Department des etudes de piles, service de physique mathematique, 91 - Gif-sur-Yvette (France) %2OECD Dragon Project, Paris (France) %J[] %K21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS, DRAGON REACTOR, HTGR TYPE REACTORS, EXPERIMENTAL REACTORS %PMedium: ED; Size: 12 pages %TA comparison between thorium-uranium and low enrichment uranium cycles in the high temperature reactors %XIn a previous report, it was shown that the Uranium cycle could be used as well with multi-hole block (GGA type) as with tubular elements. Now, in a F.S.V. geometry, a comparison is made between Thorium cycle and Uranium cycle. This comparison will be concerned with the physical properties of the materials, the needs of natural Uranium, the fissile material inventory and, at last, an attempt of economical considerations. In this report the cycle will be characterizd by the fertile material. So, we write ''Thorium cycle'' for Highly Enriched Uranium - Thorium cycle and ''Uranium cycle'' for low Enrichment Uranium cycle. %0Technical Report %NDCPM-16/CEA-1;TRN: XN73OS011 %1 %CNEA %Rhttps://doi.org/ TRN: XN73OS011 OSTI %GEnglish