L.J. Wittenberg

Lunar Source of 3 He for Commercial Fusion Power

AbstractAn analysis of astrophysical information indicates that the solar wind has deposited an abundant, easily extractable source of 3He onto the surface of the moon. Apollo lunar samples indicat...

Apollo - An advanced fuel fusion power reactor for the 21st century

A preconceptual design of a tokamak reactor fueled by a D-He-3 plasma is presented. A low aspect ratio (A=2-4) device is studied here but high aspect ratio devices (A > 6) may also be quite attractive. The Apollo D-He-3 tokamak capitalizes on recent advances in high field magnets (20 T) and utilizes rectennas to convert the synchrotron radiation directly to electricity. The overall efficiency ranges from 37 to 52% depending on whether the bremsstrahlung energy is utilized. The low neutron wall loading (0.1 MW/m/sup 2/) allows a permanent first wall to be designed and the low nuclear decay heat enables the reactor to be classed as inherently safe. The cost of electricity from Apollo is > 40% lower than electricity from a similar sized DT reactor.

Dry wall chamber issues for the SOMBRERO laser fusion power plant

A reassessment of the SOMBRERO laser driven fusion power plant that was designed in 1990-91 has been conducted. New information and analysis has confirmed most of the original design decisions except that the tritium inventory in the blanket may be larger than originally calculated. Possible methods of lowering the tritium inventory are described along with a discussion of the critical issues that still remain 10 years after the original design was completed.

Summary of Apollo, a D-3He tokamak reactor design

AbstractThe key features of Apollo, a conceptual D-3He tokamak reactor for commercial electricity production, are summarized. The 1000-MW(electric) design utilizes direct conversion of synchrotron radiation power and thermal conversion of transport, neutron, and bremsstrahlung radiation power. The direct conversion method uses rectennas, and the thermal conversion cycle uses an organic coolant. Apollo operates in the first-stability regime, with a major radius of 7.89 m, a peak magnetic field on the toroidal field coils of 19.3 T, a 53-MA plasma current, and a 6.7% beta value. The low neutron production of the D-3He fuel cycle greatly reduces the radiation damage rate and allows a full-lifetime first wall and structure made of standard steels with only slight modifications to reduce activation levels. The reduced radioactive inventory and afterheat give significant safety and environmental advantages over deuterium-tritium reactors.

SIRIUS-T, an Advanced Tritium Production Facility Utilizing Symmetrically Illuminated Inertial Confinement Fusion

SIRIUS-T is a study of an advanced tritium production facility which utilizes direct drive symmetric illumination inertial confinement fusion provided by a KrF laser. Symmetrically illuminated reactor systems have some very unique problems which have to do with a large number of beams. In SIRIUS-T, a single shell ICF target is illuminated by 92 symmetrically distributed beams around a spherical cavity of 4 m radius. The driver energy is 2 MJ and the target gain 50. The first wall consists of graphite tiles bonded to an actively cooled vanadium structure. There is a 1.0 torr xenon buffer gas in the cavity. The structural material is the vanadium alloy V-3Ti-1Si, the breeding/cooling material is lithium 90% enriched in Li-6 and the neutron multiplier is Be, giving a tritium breeding ratio of 1.903. The total tritium inventory in the reactor is 184 g. A routine release of 29 Ci/d is estimated and the maximum accidental release is 19.9 g. At 100 MJ yield, a repetition rate of 10 Hz and an availability of 70%, a tritium surplus of 33.3 kg per calendar year is achieved. Using 100% debt financing, and a 30 full power year (FPY) reactor lifetime, the cost of tritium production is

Evolution of light ion driven fusion power plants leading to the LIBRA-SP design

8,885/g at 5% interest on capital and

A near symmetrically illuminated direct drive laser fusion power reactor - SIRIUS-P

14,611/g at 10% in 1990 dollars.

Safety Analysis for “SOMBRERO”: A KrF Laser Driven IFE Reactor

The use of light ion or electron beams to compress matter to the densities required for fusion has been proposed for more than 20 years. In the past ten years, a series of light ion beam power plant conceptual designs have been published under the generic name LIBRA. Considerable advances in both physics and technology have allowed major improvements from the design performance of the earliest LIBRA 330 MW{sub e} power plant to the more recent 979 MW{sub e} LIBRA-LiTE, and the 1000 MW{sub e} LIBRA-SP reactors. The recent declassification of target designs allows more realistic target spectra, gains, and injection parameters to be analyzed. The pulsed power driver technology has matured to the point that Helia induction technology can be tested in the laboratory under single pulse conditions and confidently extrapolated to LIBRA repetition rates. New concepts for protecting the first structural wall of the reactor have been developed; the use of flexible INPORT (INhibited Flow in PORous Tube) and rigid PERIT (PErforated RIgid Tube) units allow the reflector and first wall to last the lifetime of the power plant. The use of PbLi eutectic alloy has greatly improved the safety features of these reactors and the economics ofmorexa0» all three compare very favorably to the tokamak, laser, and heavy ion beam reactors.«xa0less

Envrionmental and Safety Aspects of “OSIRIS”: A Heavy Ion Beam Driven IFE Reactor

This paper describes the design of a 1000 MWe inertially confined fusion power reactor utilizing near symmetric illumination provided by a KrF laser. The nominal laser energy is 3.4 MJ, the target ...

Safety and Environmental Characteristics of Recent D- 3 He and DT Tokamak Power Reactors

Activation and safety analysis has been performed for the chamber, shield and Li2O coolant of the inertial confinement fusion (IFE) reactor SOMBRERO. The total activities generated in the reactor graphite chamber and steel-reinforced concrete shield at shutdown are 0.054 and 10.12 MCi, respectively. The biological dose rate at the back of the shield drops to 1.6 mrem/hr after one day of shutdown allowing for hands-on maintenance. Radwaste classification has shown that both the chamber and shield would easily qualify as Class A low level waste (LLW) according to the 10CFR61 waste disposal concentration limits (WDL). At the same time, the Li2O granules would qualify as Class C LLW. The maximum public dose from atmospheric effluents is 0.93 mrem/yr. The dose is due to tritium and its maximum value occurs at the reactor site boundary which is 1 km away from the point of tritium release. Only a small fraction (0.44%) of the graphite first wall would be mobilized during a loss of coolant accident (LOCA). During such an accident, the shield temperature would only increase by a few degrees releasing a very small fraction of its radioactive inventory. The total tritium inventory in the containment building which is assumed to be released at the onset of a severe accident is 182.6 grams. The estimated whole body (WB) early dose from a severe accident resulting in the failure of the reactor containment is 2.22 rem. The very low off-site dose eliminates the need for N-stamp nuclear grade components in SOMBRERO.