As part of the Phase I effort on Program Element-II (PE-II) of the Office of Fusion Energy/Argonne National Laboratory First Wall/Blanket/Shield Engineering Technology Program, a study has been performed to develop preconceptual hardware designs and preliminary test program descriptions for two fission-reactor-based tests of a water-cooled, solid-breeder fusion reactor blanket concept. First, a list of potentially acceptable reactor facilities is developed, based on a list of required reactor characteristics. From this set of facilities, two facilities are selected for study: the Oak Ridge Research Reactor (ORR) and the Power Burst Facility (PBF). A test which employs a cylindrical unit cell of a solid-breeder fusion reactor blanket, with pressurized-water cooling is designed for each facility. The test design is adjusted to the particular characteristics of each reactor. These two test designs are then compared on the basis of technical issues and cost. Both tests can satisfy the PE-II mission: blanket thermal hydraulic and thermomechanical issues. In addition, both reactors will produce prototypical tritium production rates and profiles and release characteristics with little or no additional modifications.
A large-volume, distributed, pulsed, 14 MeV neutron source, which utilizes the high powered (270-GW) Power Burst Facility (PBF) at the Idaho National Engineering Laboratory, is described. The concept of utilizing existing fission test reactors to test fusion first wall/blanket (FW/B) components and systems has been adequately documented. In all previous scenarios, the normal fission spectrum (including tailoring) was shown to produce adequate heating profiles and some tritium breeding. However, one recognized shortcoming has been the absence of the 14 MeV neutron component. This paper describes a scheme whereby the fission neutrons would be employed to produce the desired 14 MeV component. The data obtained from tests in this large-volume [20 em (8 in.) in diameter and 90 em (36 in.) in length], distributed neutron source will pertain to both near-term (Tokamak Fusion Test Reactor—TFTR) and future pulsed fusion machines. Specifically, application requiring high flux but low fluence is foreseen in the areas of dosimetry benchmarking for tritium breeding performance code verification. As a general purpose, FW/B integrated technology development capability, the PBF is shown to be pertinent to addressing the bulk-heated, solid breeder blanket thermal and mechanical issues; tritium permeation in the presence of radiation, and barrier development in the prototypical radiation environment associated with the first wall; issues associated with the technology of breeder materials; and in situ tritium recovery process characterization and system development.
The overall objective of this task is to investigate the extent to which the power density in the FED breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow testing of advanced reactor blanket modules on INTOR at representative conditions. The tentative approach adopted for this task consists of three parts. First, the requirements for augmented heating of the test module are outlined for different applications of interest. Second, methods are identified which have potential for augmenting the heating power in a test module, and this list of methods is narrowed to those which appear to be most useful. Finally, these methods are examined in more detail to determine the practical benefits of employing each.
Recent theoretical investigations have pointed to considerable uncertainty in estimating the amount of tritium which will permeate the first wall of a fusion reactor and enter the primary coolant system due in part to the implantation of energetic ions. An experiment is being planned to study this problem in a small test reactor where the /sup 3/He(n,p)/sup 3/T reaction is used to generate protons and tritons for implantation in and permeation of a simulated first wall. By comparing the amount of tritium moving through the wall in the presence of implantation with that in its absence while maintaining the time background partial pressure and temperature, the efflct of implantation on tritium permeation will be determined. The experiment offers an interesting and important complement to similar experiments based on plasmas or ion beams.
The testing of fusion materials and components in fission reactors will be increasingly important in the future due to the near-term lack of fusion engineering test devices, and the long-term high demand for fusion testing when they do become available. Fission testing is capable of filling many gaps in fusion reactor design information, and should be aggressively pursued. EG and G Idaho has investigated the application of fission testing in three areas, which are discussed in this paper. First, work was performed on the irradiation of magnet insulators. This work is continuing with an improved test environment. Second, a study was performed which indicated that a fission-suppressed hybrid blanket module could be effectively tested in a reactor such as the Engineering Test Reactor (ETR), closely reproducing the predicted performance in a fusion environment. Finally, a conceptual design is presented for a fission-based Integrated Test Facility (ITF), which can accommodate entire wall/blanket (FW/B) modules for testing in a nuclear environment, simultaneously satisfying many of the FW/B test requirements. This ITF can provide a cyclic neutron/gamma flux, as well as the necessary module support functions.
We have examined requirements for a fusion instrumentation and control development program to determine where emphasis is needed. The complex, fast, and closely coupled system dynamics of fusion reactors reveal a need for a rigorous approach to the development of instrumentation and control systems. A framework for such a development program should concentrate on three principal need areas: the operator-machine interface, the data and control system architecture, and fusion compatible instruments and sensors. System dynamics characterization of the whole fusion reactor system is also needed to facilitate the implementation process in each of these areas. Finally, the future need to make the instrumentation and control system compatible with the requirements of a commercial plant is met by applying transition technology. These needs form the basis for the program tasks suggested.
This paper examines the usefulness of testing hybrid fusion-fission blanket components in fission reactors, and reports the results of calculations indicating that blanket heating profiles, tritium breeding rates, fertile breeding rates, and fast-fission rates can be accurately duplicated in a fission reactor test. These results indicate that fission testing can play a major part in the hybrid blanket development program.