Engineering of Fuel Plates on Uranium-Molybdenum Monolithic: Critical Issues
Engineering of nuclear fuels using monolithic plates of uranium-molybdenum and Al-6061 cladding is the current challenge for research and test reactors. The main drawback of the manufacture of monolithic nuclear fuel was analyzed using two surface coating methods: aluminum sputtering and transient liquid phase bonding (TLPB). Coating was done with a commercial alloy of Al-Si (R-4047). These techniques were used to improve the metallurgical bonding between the UMo and the cladding by rolling. Finally, design parameters and manufacture of UMo plate fuels were established. Mechanical tests were used to characterize the plates, resulting in UTS values of about 700 and 1000 MPa for the UMo alloys. These results are complemented with metrological analyses, X-Ray diffraction (XRD), thermal analyses, and metallography. X-rays and ultrasound scanners were used to monitor bonding and the co-rolling effects. These initial results show the main obstacles to the engineering development of UMo monolithic plate fuels with Al-6061 cladding, and these are discussed herein.
Superconductivity in U-T alloys (T = Mo, Pt, Pd, Nb, Zr) stabilized in the cubic γ-U structure by splat-cooling technique
Abstract We succeed to retain the high-temperature (cubic) γ-U phase down to low temperatures in U-T alloys with less required T alloying concentration (T = Mo, Pt, Pd, Nb, Zr) by means of splat-cooling technique with a cooling rate better than 10 6  K/s. All splat-cooled U-T alloys become superconducting with the critical temperature T c in the range of 0.61 K–2.11 K. U-15 at.% Mo splat consisting of the γ-U phase with an ideal bcc A2 structure is a BCS superconductor having the highest critical temperature (2.11 K).
The interdiffusion of uranium and aluminium
Results are given of measurements of the width, as a function of temperature and pressure, of the diffusion zone formed by the interdiffusion of uranium and aluminium and of the relative penetration of uranium into aluminium and of aluminium into uranium. 
 
The experiments are unusual among diffusion measurements in showing an appreciable accelerating effect of pressure on the rate of interdiffusion. This is most marked for temperatures below ∼ 540°C. The penetration of the uranium into the aluminium is about 214 times faster than that of the aluminium into the uranium. 
 
The results of a microscopical and X-ray examination of the diffusion zone are presented, and a discussion is given of the possible origins of the pressure effect.