GEO PHYSI CAL SUR VEY ( GPR ) IN WEST SAQQARA ( EGYPT ) : PRE LIMI NARY RE MARKS
Ab stract Geo phys i cal in ves ti ga tions in West Saqqara area were part of the ar chae o log i cal field work of the Pol ish-Egyp tian ar chae o log i cal mis sion dur ing the cam paign in 2012. The main pur pose of geo phys i cal prospection us ing the groundpen e trat ing ra dar (GPR) was to de ter mine the lo ca tion of po ten tial un der ground se pul chral struc tures. Dur ing the GPR sur vey, op ti mal depth pen e tra tion was achieved due to dry rocks and mono lithic struc ture of the lime stone pla teau on which the an cient cem e tery was lo cated. Us ing an tenna of 100 MHz, the depth of pen e tra tion was up to 45 m and with an tenna of 250 MHz, up to 15 me ters. Three main groups of ar chae o log i cal struc tures were iden ti fied: sar coph agi and mum mies, burial shafts; mo bile ob jects (solid rock blocks as frag ments of tombs). One of the main goal of the GPR sur vey was to track the route of the west ern part of the Dry Moat, ex pressed by a wide and shal low de pres sion spread ing to wards north-south. The re sults of geo phys i cal in ves ti ga tions sug gest that Saqqara pla teau is an ideal site for us ing GPR sur vey ing tech nol ogy.
AP PLI CA BIL ITY OF GROUND PEN E TRAT ING RA DAR ON DESERT AR CHAE O LOG I CAL SITES: A CASE STUDY FROM THE SAQQARA NE CROP O LIS IN EGYPT
Fa bian Welc, Rados3aw Mieszkowski, Sebastian Kowalczyk , Jerzy Trzcinski 1 In sti tute of Ar chae ol ogy, Car di nal Stefan Wyszynski Uni ver sity, ul. Woycickiego 1/3, no. 23, 01-938 Warszawa, e-mail: f.welc@uksw.edu.pl 2 Uni ver sity of War saw, Fac ulty of Ge ol ogy, In sti tute of Hydrogeology and En gi neer ing Ge ol ogy, ul. wirki i Wigury 93, 02-089 War saw, e-mails: r.mieszkowski@uw.edu.pl; jerzy.trzcinski@uw.edu.pl; s.kowalczyk@uw.edu.pl
Phase characterisation of simulated high burn-up UO2 fuel
Abstract To determine the lattice constant variation with burn-up and the oxidation behaviour at high temperatures, simulated UO2-spent fuels with burn-ups up to 200 GWd tM−1 were prepared by cold pressing and sintering and characterised by X-ray diffraction analysis and thermogravimetry. The fcc-lattice parameter of the sintered samples determined at room temperature, showed a continuous decrease with the simulated burn-up. During oxidation the conversion of the simulated fuels to the (U,FP)4O9 and (U,FP)3O8-type phases was strongly delayed when the simulated burn-up exceeded 80 GWd tM−1. Also, at high burn-ups (>100 GWd tM−1), large fractions of the (U,FP)4O9-type phase remained untransformed to (U,FP)3O8 after prolonged exposure to air at 950–1000°C. This suggests a marked widening of the (U,FP)4O9-phase field when the amount of substituted uranium atoms exceeds values of about 8%.