Breeder reactors in france

France relies on nuclear power as an important part of her energy program. Anticipating problems with the availability of natural uranium before the year 2020, the French have been pursuing a three-stage program of development of breeder reactors. The third reactor in this program, the near-commercial plant Super Phenix Mark I, is expected to reach power operation in 1983. Although there are still some uncertainties, particularly about the date when the breeder will become competitive with other energy sources, the outlook is considered favorable and preliminary designs for commercial plants are under way.     

Radioactive wastes from fusion reactors

Calculation of the amount of tritium released from a hypothetical fusion reactor shows that it is 2 x 10(5) the amount released by generation of an equivalent amount of electricity by a fission reactor. Release of the tritium generated by a power economy, if the nuclear power were all fusion, would result in unacceptable worldwide dosages by the year 2000.     

Microstructured optical fibers as high-pressure microfluidic reactors

Deposition of semiconductors and metals from chemical precursors onto planar substrates is a well-developed science and technology for microelectronics. Optical fibers are an established platform for both communications technology and fundamental research in photonics. Here, we describe a hybrid technology that integrates key aspects of both engineering disciplines, demonstrating the fabrication of tubes, solid nanowires, coaxial heterojunctions, and longitudinally patterned structures composed of metals, single-crystal semiconductors, and polycrystalline elemental or compound semiconductors within microstructured silica optical fibers. Because the optical fibers are constructed and the functional materials are chemically deposited in distinct and independent steps, the full design flexibilities of both platforms can now be exploited simultaneously for fiber-integrated optoelectronic materials and devices.     

Inherently safe reactors and a second nuclear era

The Swedish PIUS reactor and the German-American small modular high-temperature gas-cooled reactor are inherently safe-that is, their safety relies not upon intervention of humans or of electromechanical devices but on immutable principles of physics and chemistry. A second nuclear era may require commercialization and deployment of such inherently safe reactors, even though existing light-water reactors appear to be as safe as other well-accepted sources of central electricity, particularly hydroelectric dams.     

Comparative breeding characteristics of fusion and fast reactors

Expressions are developed to allow ready comparison of a hybrid fission-fusion plant and a fast breeder with respect to the number of thermal reactors that their fissile production could support, both for their feed requirements and for the new inventory needs of an expanding industry. These relations are expressed in terms of the neutron multiplication factor obtained in the fusion blanket, and the analogous quantities represented by the conversion ratios of the fast and thermal fission associated with the comparison. Results are presented graphically both for the steady state and for industries of arbitrary growth rate, and include the influence of tritium production requirements. Even a modest blanket neutron multiplication factor could enable the hybrid fusion system greatly to outperform the fast breeder on this simple basis of material balances.