STARFIRE,a commercial tokamak power plant design

STARFIRE is a design for a conceptual commercial tokamak electrical power plant based on the deuterium/tritium/lithium fuel cycle. In addition to the goal of being technologically credible, the design incorporates safety and environmental considerations. STARFIRE is considered to be the tenth in a series of commercial fusion power plants.STARFIRE has a 7-m major radius reactor producing 1200 MW of net electrical power from 4000 MW of thermal power, with an average neutron wall load of 3.6 MW/m². The aspect ratio is 3.6 and a D-shaped plasma with a height-to-width ratio of 1.6 and average toroidal beta of 0.067 is used. The maximum magnetic field is 11T. Availability goals have been set at 85% for the reactor and 75% for the complete plant including the reactor.The major features for STARFIRE include a steady-state operating mode based on a continuous rf lower-hybrid current drive and auxiliary heating, solid tritium breeder material, pressurized water cooling, limiter/vacuum for impurity control, most superconducting EF coils outside the TF superconducting coils, fully remote maintenance, and a low-activation shield.     

The Neglected Water Rebound Effect of Income and Employment Growth

Water Resources Management - The water footprint assessment, particularly for the agricultural sector, is often a valuable input to water policy formation globally. Efforts on reducing it focus on...     

Using Real Options Theory to Irrigation Dam Investment Analysis: An Application of Binomial Option Pricing Model

This paper demonstrates the utility of the real options approach to irrigation dam investment analysis. The main objective is to show how to calculate the option values of selected options that may be available to managers of irrigation dam investments. The paper provides an empirical application, which compares an irrigation dam investment using the static Net Present Value (NPV) model and the real options approach and shows how it can be adopted to model uncertainty and managerial flexibility in dam management. Four management options are used for the real options approach: an option to delay the investment, an option to enlarge the dam, an option to abandon the dam, and multiple options that evaluated all three options together. All options were evaluated using the binomial option pricing model, where water values are assumed to follow a multiplicative binomial process. The analysis show that although the traditional NPV approach accepted the investment as profitable the option approach provided better results showing that all three options were highly valuable if exercised. When real options are considered, the traditional NPV model for assessing the profitability of a dam investment may fail to provide an adequate decision-making framework because it does not properly value management’s ability to adjust to shocks in the economy, as well as risks and uncertainty.     

The Potential for Advanced Limiter/Divertor Systems

The Advanced Limiter-divertor Plasrna-facing Systems (ALPS) program was initiated in FY 1998 in order to evaluate the potential for improved performance and lifetime for plasma-facing systems. The main goal of the program is; to demonstrate the advantages of advanced limiter/divertor systems over conventional systems in terms of power density capability, component lifetime, and power conversion efficiency, while providing for safe operation and minimizing impurity concerns for the plasma.     

Vanadium alloys for fusion reactor applications

Fusion reactors will produce a severe operating environment for structural materials. The material should have good mechanical strength and ductility to high temperature, be corrosion resistant to the local environment, have attractive thermophysical properties to accommodate high heat loads, and be resistant to neutron damage. Vanadium alloys are being developed for such applications, and they exhibit desirable properties in many areas. Recent progress in vanadium alloy development indicates good strength and ductility to 700°C, minimal degradation by neutron irradiation, and reduced radioactivity compared with other candidate alloy systems.     

A Socioeconomic Valuation of an Irrigation System Project Based on Real Option Analysis Approach

Traditional net present value methods used to evaluate potential projects make no allowance for flexibility and assume a static environment. The concept of real options has extended into irrigation systems to model design flexibility in the realistically uncertain environment. In particular, this article extends the evaluation techniques of an irrigation dam by combining the real options approach along with the traditional on (Discount Cash Flow). However, whereas financial options are well-defined traded contracts, real options in irrigation systems are a priori undefined, complex and interdependent. Moreover, irrigation systems involve many more options than designers could consider. Therefore designers need to identify the real options most likely to offer good flexibility and the most value. This paper demonstrates the ease that irrigation systems economic analysis with risk analysis and real options can be valued by simulation software that is readily available to owners of personal computers. Sequentially, Discount Cash Flow analysis accompanied with real options approach facilitates decision making and encourages more sophisticated and realistic economic analysis of irrigation systems.     

Possible THz Bloch gain in dc–ac-driven superlattices

We study theoretically the feasibility of amplification and generation of THz radiation in dc–ac-driven semiconductor superlattices in the absence of electric domains. We find that if in addition to dc bias strong ac pump fields are applied, Bloch gain profile for a small THz signal can be achieved under conditions of positive static differential conductivity. We briefly review the case of THz pump and present preliminary results on the use of pump fields belonging to the microwave frequency band.