Remote-area power supply systems

The Need for Remote-area Power-supply Systems... 

REMOTE-AREA POWER-SUPPLY (RAPS) SYSTEMS AND THE VALVE-REGULATED LEAD-ACID BATTERY... 

Much of the recent advancement of VRLA technology has been achieved through a co-operative research effort under the auspices of the Advanced Lead-Acid Battery Consortium (ALABQ. The main effort has been directed towards the development of VRLA battery systems for new-generation road transportation — electric and hybrid electric vehicles — that will reduce fuel consumption and lower emissions. The progress gained in this endeavour will ultimately also benefit the enormously important markets in telecommunications and remote-area power supplies. 

What is mentioned above is obviously expected for the nuclear energy in the twenty-first century. Some concepts about FRs as well as LWRs have already been su ested, and their design studies have also been carried out. It is expected that these concepts will be developed and used to create the above mentioned nuclear energy systems the safety systems to be described more simply, the economical nuclear energy systems to be placed near metropolises, and the power supply systems in remote areas far fi"om transmission networks. These ideas are also applicable to other systems such as reprocessing plants instead of one large plant that can reprocess spent fuel for tens of reactors, the installation of smaller plants is under discussion along with the discussion on advanced fuel cycle concepts. 

Currently, remote I/O systems of several manufacturers are available for operation in zone 1 or Division 1. To a large extent, these systems are based upon the technology of intrinsic safety. The power supply only is designed according to another type of protection, e.g. flameproof enclosure - d A remote I/O suitable for hazardous areas may be an integration of input (I) and output (O) assembly units of automation systems and of Ex i-isolators of classic design. The installation may be made in a hazardous area and supersede the classic field distribution box (terminal box). Standardized fieldbus systems may be used for data transmission from/to the automation system. These remote I/O systems for hazardous areas are characterized as follows ... 

The RAPED could be useful for power systems on islands where diesel generators are currently employed. Other expected applications are power systems for ore deposit mining and seawater desalination plants in remote areas. Many ore deposits are uneconomic because they are located in very remote places, too distant from the usual sources of energy. Energy supply from the RAPED could improve the economics for many projects, which would otherwise be abandoned. 

The two applications for which this reactor is being developed viz., as a source of process heat for hydrogen production by splitting water and as a compact nuclear power pack to supply electricity in remote areas unconnected to the grid system, have a large potential market, especially in developing countries. 

The four divisions (guard lines) of the protection and safety monitoring system and its uninterruptible power supply, the electrical penetrations through the containment, portions of the plant control system, the main control room and the remote shutdown workstation are concentrated within the northern section of the Auxiliary Building. A large fire or explosion in this area could render these features imusable for a significant amount of time. Such an event would most likely result in an immediate reactor trip, due to the loss of power and control... 

In practice, the suitability of a reaction system is determined by the kinetics of the reaction, which depends on temperature, pressure of gases, electrode polarization, surface area of electrodes, and presence of a catalyst. A fuel cell that is thermodynamically and kinetically feasible must be considered from an econonuc viewpoint before it is accepted. Thus, since hydrogen, hydrazine, and methanol are too expensive for general application, their use in fuel cells has been limited to special cases. Hydrogen has been used for fuel cells in satellites and space vehicles, in which reliability and lightness are more important than cost. Hydrazine fuel cells have been used in portable-radio power supplies for the United States Army because of their truly silent operation. Methanol fuel cells have been used to power navigation buoys and remote alpine television repeater stations because such power systems are comparatively free from maintenance problems over periods of a year or more. The polarization at the electrodes of a fuel cell is the most important single factor that limits the usefulness of the cell. The various polarization characteristics for a typical fuel cell are plotted separately as a function of current density in Fig. 9.11. 

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