G. E. Besenbruch

Tritium Inventory of Inertial Fusion Energy Target Fabrication Facilities: Effect of Foam Density and Consideration of Target Yield of Direct Drive Targets

The tritium inventory of direct drive inertial fusion energy (IFE) target filling facilities is examined in the interest of minimizing the tritium inventory. A model is described that has been developed to evaluate the tritium inventory of the target filling process as a function of filling and layering parameters, as well as target design parameters. Previous studies by A. Nobile et al. showed that the temperature and the fill system void fraction have a significant effect on the tritium inventory. The current study uses the model to examine the effect of deuterium-tritium (DT) ice layering time and density of the CH foam in the target on the tritium inventory. The study shows that increasing the foam density and decreasing the DT ice layering time significantly reduce the tritium inventory. Fortunately, one-dimensional target design calculations indicate that the foam density in the direct drive target can be increased to ~200 mg/cm3 without significant degradation of the target yield. Having evaluated and minimized the theoretical tritium inventory, calculations were performed with more realistic batch filling scenarios. The inventories associated with “real” filling scenarios approach the theoretical minimum inventory as the number of batches is increased, resulting in tritium inventories that seem acceptable for future IFE target DT filling facilities.

Developing a commercial production process for 500 000 targets per day : A key challenge for inertial fusion energy

As is true for current-day commercial power plants, a reliable and economic fuel supply is essential for the viability of future Inertial Fusion Energy (IFE) [Energy From Inertial Fusion, edited by W. J. Hogan (International Atomic Energy Agency, Vienna, 1995)] power plants. While IFE power plants will utilize deuterium-tritium (DT) bred in-house as the fusion fuel, the “target” is the vehicle by which the fuel is delivered to the reaction chamber. Thus the cost of the target becomes a critical issue in regard to fuel cost. Typically six targets per second, or about 500 000∕day are required for a nominal 1000MW(e) power plant. The electricity value within a typical target is about

Addressing the issues of target fabrication and injection for inertial fusion energy

3, allocating 10% for fuel cost gives only 30 cents per target as-delivered to the chamber center. Complicating this economic goal, the target supply has many significant technical challenges—fabricating the precision fuel-containing capsule, filling it with DT, cooling it to cryogenic temperatures, layering the DT into a unifo...

Development of a New Horizontal Rotary GDP Coater Enabling Increased Production

Addressing the issues associated with target fabrication and injection is a major part of an international program to establish the feasibility of inertial fusion energy (IFE), both for laser-driven and heavy-ion driven concepts. A summary of the unique materials science and chemistry research programs associated with supplying targets for an IFE power plant is presented. The cost of manufacturing targets for commercial power applications is a significant perceived feasibility issue for IFE, and preliminary estimates of Target Fabrication Facility costs are discussed for both direct and indirect drive systems.

Evaluation of Fluidized Beds for Mass Production of IFE Targets

Abstract Providing glow discharge polymer (GDP) coatings is a key step in Inertial Confinement Fusion (ICF) target production. Typical target delivery quantities may require several GDP coating runs consisting of up to 80 mandrels per batch. This work undertakes research and development to create a new configuration for the GDP coating apparatus that will enable batch sizes into the hundreds or thousands. This will reduce costs associated with target production and make delivery of ICF targets more efficient. In addition, there is a synergy between this work and Inertial Fusion s’Energy (IFE’s) need for half a million targets per day for energy production, as well as future commercial applications. Recently we have demonstrated the capability to meet the NIF CH surface standard, confirmed via statistical sampling, in a 400 capsule batch coated with 10 μm of GDP, a key benchmark for successful coatings.

Demonstrating a Cost-Effective Target Supply for Inertial Fusion Energy

Abstract Of the building blocks of an inertial fusion energy (IFE) plant, target fabrication remains a significant credibility issue. For this reason, an extensive parametric study has been conducted on mass production of glow discharge polymer (GDP) shells in a vertical fluidized bed. Trans-2-butene was used as a reactant gas with hydrogen as a diluting and etching agent. Coating rates in the range of 1 to 2 μm/h were demonstrated on batches of 30 shells where National Ignition Facility-quality surfaces were obtained for 3- to 5-μm-thick coatings. Thick coatings up to 325 μm were also demonstrated that are visually transparent, without void and stress fracture. A phenomenological understanding of the GDP growth mechanisms to guide future experiments was further established. Specifically, gas-phase precipitation and high-impact collisions were identified as the main surface-roughening mechanisms. The former produces dense cauliflower-like surface patterns that can be eliminated by adjusting the gas flow rates and the flow ratio. The latter produces isolated domelike surface defects that can be reduced by introducing concerted motion between the shells. By converting from a vertical to a horizontal configuration, fully transparent coatings were obtained on 350 shells. Collisions in a fluidized bed have been identified as the limiting factor in meeting IFE specifications, and a related-rotary kiln technique is recommended for scale-up.

Construction Materials Development in Sulfur-Iodine Thermochemical Water-Splitting Process for Hydrogen Production

Abstract The “Target Fabrication Facility” (TFF) of an IFE power plant must supply about 500,000 targets per day. The targets are injected into the target chamber at a rate of 5-10 Hz and tracked precisely so the driver beams can be directed to the target. The feasibility of developing successful fabrication and injection methodologies at the low cost required for energy production (about

ALTERNATIVE FLOWSHEETS FOR THE SULFUR-IODINE THERMOCHEMICAL HYDROGEN CYCLE

0.25/target, about 104 less than current costs) is a critical issue for inertial fusion. To help identify major cost factors and technology development needs, we have utilized a classic chemical engineering approach to the TFF. The analyses assume an “nth-of-a-kind” TFF and utilize standard industrial engineering cost factors. The results indicate that the direct drive target can be produced for about

Hydrogen as a Fuel for DOD

0.16 each. Iterations are still underway for the indirect drive target. These cost analyses assume that the process development is accomplished to allow scaling of current laboratory methods to larger sizes, while still meeting target specifications. A development program is underway at various laboratories to support this scale-up.