Commercial Fusion Reactor Research Articles

Tokamak Fusion Reactors with Less Than Full Tritium Breeding

A study of commercial tokamak fusion reactors with tritium concentrations and tritium breeding ratios ranging from full deuterium-tritium operation to operation with no tritium breeding is presented. The design basis for these reactors is similar to those of STARFIRE and WILDCAT. Optimum operating temperatures, sizes, toroidal field strengths, and blanket/ shield configurations are determined for a sequence of reactor designs spanning the range of tritium breeding, each having the same value of beta, thermal power, and first-wall heat load. Additional reactor parameters, tritium inventories and throughputs, and detailed costs are calculated for each reactor design. The disadvantages, advantages, implications, and ramifications of tritium-depleted operation are presented and discussed.

Issues in strategy for an irradiation program on fusion structural materials

This paper summarizes major issues in evaluating the use of advanced fusion devices as the principal radiation sources for the development of structural materials for commercial fusion reactors and focuses on work performed for the 1982 FED/INTOR study in the “Engineering Testing” task. The general objective of this task was to estimate the benefit for a DEMO reactor resulting from irradiation tests on structural materials in an engineering reactor (e.g. FED/INTOR). Some background information on radiation sources is also presented.

Materials handbook for fusion energy systems

Three years ago the Office of Fusion Energy authorized the creation of a materials data book for the purpose of assisting personnel involved in concept evaluation, design safety analysis, and performance/verification studies of near term experimental and commercial fusion reactor designs. This data book eventually became known as the Materials Handbook for Fusion Energy Systems (MHFES) and since its inception, has been transformed from an idea into a working data book with copies currently in use at the national laboratories, universities and industries which are active in the field of fusion energy.

An Analysis of Activation And the Impact of Tritium Breeding Media and Structural Materials for a Commercial Tokamak Fusion Reactor Design

Activation analysis has been conducted for several primary fusion blanket materials based on a model of a commercial tokamak fusion reactor design, STARFIRE. The blanket materials studied include two solid tritium breeders, viz., Li/sub 2/O and ..cap alpha..-LiAlO/sub 2/, and four candidate structural materials, viz., PCA stainless steel, V15Cr5Ti, Ti6Al4V, and Al-6063 alloys. The importance of breeder material activation is identified in terms of its impurity contents such as potassium, iron, nickel, molybdenum, and zirconium trace elements. The breeder activation is also discussed with regard to its potential for recycling and its impact on the lithium resource requirements. The structural material activation is analyzed based on two measures, volumetric radioactivity concentration and contact biological dose due to decay gamma emission. Using the radioactivity concentration measure, it is revealed that a substantial advantage exists from a viewpoint of radwaste management, which is inherent in fusion reactor designs based on potential low-activation alloys such as V15Cr5Ti, Ti6Al4V, and Al-6063. On the other hand, from the dose standpoint, the V15Cr5Ti alloy is found to be the only alloy for which one could realize a significant dose reduction (below 2.5 mrem/h) within about100 yr after shutdown, possibly by some extrapolation on alloy purification techniques.

Prospects for Low-Activity Aluminum Structures

High-purity, low-activity powder metallurgy aluminum alloys can be developed for use in a fusion reactor at 300 to 400/sup 0/C using helium as a heat transfer medium. Hot water as a coolant may limit aluminum to 200/sup 0/C. From a heat transfer point of view, based on the dual- or two-temperature design approach, commercial fusion reactor blanket designs appear to be feasible. To meet all of the blanket design requirements feasibility requires quantification of thermal hydraulics, materials, neutronics, and material responses. Also, radiation damage and lifetime analyses are key issues for design qualification. Based on tests performed to date, aluminum appears well suited for experimental fusion reactors operating at wall temperatures below 200/sup 0/C.

WILDCAT: A Commercial Deuterium-Deuterium Tokamak Reactor

WILDCAT is a conceptual design of a catalyzed deuterium-deuterium tokamak commercial fusion reactor. WILDCAT utilizes the beneficial features of no tritium breeding, while not extrapolating unnecessarily from existing deuterium-tritium (D-T) designs. The reactor is larger and has higher magnetic fields and plasma pressures than typical D-T devices. It is more costly, but eliminates problems associated with tritium breeding and has tritium inventories and throughputs approximately two orders of magnitude less than typical D-T reactors. There are both a steady-state version with Alfven-wave current drive and a pulsed version. Extensive comparison with D-T devices has been made, and cost and safety analyses have been included. All of the major reactor systems have been worked out to a level of detail appropriate to a complete conceptual design.

Experimentation in the fusion materials irradiation test facility

The Fusion Materials Irradiation Test Facility (FMIT) is an accelerator-based neutron source being developed solely for fusion materials irradiation damage studies. The neutron flux magnitude and irradiation volume in the FMIT will enable thousands of materials test specimens to be simultaneously irradiated at damage rates higher than anticipated in commercial fusion reactors. This paper describes experimental capabilities in the FMIT [1]. Experimentation will take place in a heavily shielded irradiation cell, having a cubical irradiation volume of approximately 7501. Above the irradiation cell is a large hot cell that is used to handle experiments before, during and after irradiation. During irradiation, experimental hardware becomes highly activated and subsequent handling is totally remote. An overall description of the FMIT experimental areas and of the experimental test assemblies is given in sufficient detail to allow potential users of the FMIT to formulate ideas for utilizing the FMIT, and to conceptualize experimental hardware and support equipment.

High-current density coils for high-radiation environments

The limits on current density for continuous operation of indirectly cooled mineral-insulated coils are explored by thermal analysis, and the criteria for cable optimization are established. The insulation system, compacted magnesium oxide powder, has these advantages: 1) Radiation insensitivity - no detectable degradation at 1014rads, with no reason to expect this to be close to any limit. 2) Flexibility - enabling standard coil-winding practice to be followed, without the problems of fired ceramics. 3) Good thermal conductivity - 2.36 W/m.K at room temperature. 4) High-temperature stability - making the metal components of the coil determine the operational temperature limit, rather than the insulation system as in conventional coils. The cooling system avoids oxidation problems caused by radiolysis of water. Other potentially radiation-sensitive components also are discussed. An example is given of the design procedure. The feasibility of extending the technique to commercial fusion reactor coils is examined.

Plasma Behavior in Magnetically Protected Inertial Confinement Fusion Reactor Cavities

Investigations of the feasibility of commercial inertial confinement fusion (ICF) reactors have led to studies of a variety of plasma regimes and behaviors. Presented in the paper are 1. a general ...

’’Vacuum’’ layer double‐shell cryogenic inertial fusion targets

A double‐shell cryogenic target has been suggested as a possible design for commercial Inertial Fusion (IF) reactors. Fabrication techniques have been developed to the point where these targets will soon be available for experimental evaluation. Heat transfer from the fuel container to the outer shell can be provided by a low‐pressure exchange gas between the two shells. The pressure and mass of gas is controlled by both temperature and the selection of the exchange gas. In the temperature range of interest (10–35 K), helium, a noncondensable gas, permits only a variation of pressure. A condensable gas, however, allows a variation in both the pressure and the mass density within the gas between the shells. A general thermal model has been developed as a framework to evaluate the thermal characteristics of proposed candidate target designs and estimate their expected fuel‐layer uniformity.

Power/energy: Magnetic fusion power: Controlled thermonuclear fusion power using magnetic confinement nows seems practical, but the best method remains uncertain

Scientists both within and outside the fusion research field are confident that magnetic fields can confine the 100 million-Kelvin plasmas long enough for a reaction and that a demonstration commercial fusion reactor can be built by the year 2000.

Fusion Reactor Design-II (Report on the Second IAEA Technical Committee Meeting and Workshop, Madison, 1977)

A summary is given of the experimental, demonstration and commercial fusion reactor concepts presented at the Second IAEA Technical Committee Meeting and Workshop on Fusion Reactor Design. The potential role of fusion power as an inexhaustible energy source is discussed, the advances and trends in fusion reactor design assessed, and the major conclusions and recommendations of five workshop groups given.At present, designs for tokamaks are most heavily represented, with the emphasis on near-term reactor studies. Conceptual commercial reactors are becoming compact, high-power-density units. Reactor concepts are also presented for Q-enhanced mirror machines, alternate magnetic fusion concepts, and laser-and electron-beam-driven inertial confinement reactors. The fusion-fission hybrid concepts open up several approaches to fusion power, and special-topic papers cover technology problems and fusion commercialization.

Radiation effects in the fusion power programme

As the prospect of a commercial fusion reactor becomes more real, concerted research is needed into the damage that is likely to be caused by radiation during its lifetime.