Lawrence M. Lidsky

Nuclear Power and Energy Security: A Revised Strategy for Japan

SUMMARY During the period of nuclear power’s rapid growth, shared assumptions regarding uranium resources and technological capabilities led the majority of industrial nations to remarkably similar strategies for nuclear power deployment. These common assumptions motivated the choice, more than 40 years ago, of the Light Water Reactor (LWR) as the near-term power reactor, to be followed, as soon as possible, by the introduction and deployment of the Fast Breeder Reactor (FBR). The FBR, which uses much less uranium than an LWR of the same capacity, was a crucial part of the strategy because uranium was then believed to be a scarce resource. This strategy, based on the LWR producing the startup fuel for the FBR, implicitly included spent fuel reprocessing, plutonium recycle, and disposal of separated wastes in geologic repositories. Nations with limited indigenous energy reserves, most notably France and Japan, made particularly strong commitments to this strategy. This article was originally presented as a paper at the PARES Workshop: Energy Secu

DESIGN OF CLOSED-CYCLE HELIUM TURBINE NUCLEAR POWER PLANTS

This paper describes the design of two closed-cycle helium turbine electric power plants using a modular high temperature gas-cooled reactor (MGR) as heat source. The MGR-GT utilizes a direct cycle with the turbine in the primary coolant loop while the MGR-GTI uses an intermediate heat exchanger. Both plants are based on current technologies and offer busbar efficiencies in excess of 45% at generating costs competitive with other nuclear or fossil systems. The MGR-GTI indirect cycle faces less technical challenge and is easier to license under current technical and institutional realities, whereas the MGR-GT direct cycle is better able to accommodate future developments in fuel and materials and is an ultimate design capable of capturing the full economic potential through further design simplicity. The two designs thus provide an evolutionary path for the commercialization of MGR gas turbine technology.Copyright

Windowless gas targets for neutron production

A windowless deuterium gas target has been constructed for either monoenergetic or white neutron production with a 900 KeV deuteron accelerator. The target is capable of operation at 100 mbar target pressure, and can admit a beam of 5 mm transverse extent. This target is further being modified by the inclusion of an intermittent valve arrangement to reduce the flow rates in the higher pressure stages. This valve should allow operation at up to 1000 mbar with low duty factor beams.

Ion Acoustic Wave Propagation near the Ion Cyclotron Frequency

An experimental investigation of ion acoustic wave propagation near the ion cyclotron frequency is described. The acoustic wave was found to propagate along the plasma column in other than a plane wave mode, but no cyclotron resonance effects were observed.

Experimental Observations of Half‐Harmonic Instabilities in Hot‐Electron Plasmas

The fluctuation spectrum of a two‐component, hot electron plasma generated by a beam‐plasma interaction in a magnetic mirror was investigated. The unstable waves were studied with specially constructed high‐frequency, impedance matched probes. Correlation studies show that the wavenumbers of the unstable modes satisfy k⊥ae∼k‖ae∼1. The observed unstable frequencies (ω∼0.7ωce) and wavenumbers are in good agreement with those predicted by half‐harmonic electrostatic instability in a two‐component electron plasma driven by the temperature anisotropy of the hot component.

Velocity Diffusion in Resonantly Perturbed Magnetic Field

Charged particle motion in perturbed magnetic fields can often be described as a random walk on a constant energy surface in velocity space. The particle–field interaction is strongest in “resonant perturbations”—those for which the characteristic wavenumber of the field perturbation is related to υ‖, the velocity of the particle along the direction of the average magnetic field, by kυ‖ = ω, where ω is the cyclotron frequency in the average field. Such fields occur (for example) as the magnetic component of slow transverse plasma waves. The random walk is usually described by a Fokker–Planck equation whose coefficients depend on the square of the perturbation field strength. Under certain conditions, this description is incorrect. If the field amplitude is strong enough to affect the phase correlation between the field and the particle before this correlation is destroyed by fluctuations in the field, the Fokker–Planck coefficients take on half‐integral power dependences on the perturbation field strength...