The Department of Energy (DOE) is supporting research on several reactor concepts, priority is being given to the VHTR, a system compatible with advanced electricity and hydrogen electricity generation capabilities. The emphasis on VHTR reflects its potential for economically and safely producing electricity and hydrogen at high efficiency without emitting noxious gases.
Last month, the DOE announced awards of $8 million to three private companies to to perform engineering studies and develop a pre-conceptual design to guide research on the Next Generation Nuclear Plant (NGNP), a very high temperature gas-cooled nuclear reactor prototype.
Construction is scheduled to begin at Idaho National Laboratory (INL), a DOE-managed facility near Arco,Idaho, in 2016 and to be completed by 2021.
In addition to producing hydrogen, the reactor is expected to generate commercial quantities of electricity and to recycle radioactive fuel, reducing the amount of nuclear waste compared to that produced by current reactors.
The INL will issue a contract to Westinghouse Electric Company for the pre-conceptual design of the NGNP, and will later issue contracts to AREVA NP and General Atomics to perform complimentary engineering studies in the areas of technology and design tradeoffs, initial cost estimates and selected plant arrangements.
The VHTR is gas cooled and operates at extremely high temperatures, with operational fuel temperatures above 1250°C (2300°F) . Graphite walls regulate the speed of nuclear fission reaction in the core, and the VHTR uses helium to transfer heat from the reactor core to another area where it can serve an application, such as hydrogen production or electricity cogeneration.
The reactor uses a thermal neutron spectrum and a once-through uranium cycle. The VHTR system is primarily aimed at relatively faster deployment of a system for high temperature process heat applications, such as coal gasification and thermochemical hydrogen production, with superior efficiency.
The reference reactor concept has a 600-MWth helium cooled core based on either the prismatic block fuel of the Gas Turbine–Modular Helium Reactor (GT-MHR) or the pebble fuel of the Pebble Bed Modular Reactor (PBMR). The primary circuit is connected to a steam reformer/steam generator to deliver process heat. The VHTR system has coolant outlet temperatures above 1000°C (1800°F) . It is intended to be a high-efficiency system that can supply process heat to a broad spectrum of high temperature and energy-intensive, nonelectric processes. The system may incorporate electricity generation equipment to meet cogeneration needs. The system also has the flexibility to adopt U/Pu fuel cycles and offer enhanced waste minimization. The VHTR requires significant advances in fuel performance and high temperature materials, but could benefit from many of the developments proposed for earlier prismatic or pebble bed gas-cooled reactors. Additional technology R&D for the VHTR includes high-temperature alloys, fiber-reinforced ceramics or composite materials, and zirconium-carbide fuel coatings.
The VHTR system is highly ranked in economics because of its high hydrogen production efficiency, and in safety and reliability because of the inherent safety features of the fuel and reactor. It is rated good in proliferation resistance and physical protection, and neutral in sustainability because of its open fuel cycle. It is primarily envisioned for missions in hydrogen production and other process-heat applications, although it could produce electricity as well.
The Very High Temperature Reactor would inaugurate a "fourth generation" of nuclear plants. Nuclear engineers describe prototype plants built in the 1950s and 1960s as the first generation of nuclear reactors, and the commercial reactors built primarily in the 1970s, and still operating, as the second generation. Generation III plants are under construction today, primarily in Asia, and are expected to be operating until about 2030.
The NGNP research and development program is part of DOE's Generation IV nuclear energy systems initiative aimed at developing next generation reactor technologies and is authorized by Congress in the Energy Policy Act of 2005.
Irrespective of the merits of the hydrogen economy or this reactor, a date or 2021 for the construction of a prototype of a reactor to produce hydrogen seems to me to be out of line with our energy needs. If we go that way, by 2021 we will have invested significant amounts into coal based production of hydrogen. It seems to me that plug-ins and EVs using electricity are a much more efficient way to go. The electricity will have to be produced primarily by a combination of renewables, nuclear and coal. Initially the electricity can come from off peak power, but eventually more power production will be required. The amount produced by renewables will depend on how fast the technologies can be implemented, but by no means can they supply all the required incremental amounts of electricity until 2025 at the earliest. Conservation in the form of more energy efficient buildings, in addition to plug-ins and EVs, will be the other major factor in determining how fast our energy requirements grow. Please buy some compact florescent light bulbs if you haven't or more of them if you have some. As indicated in this earlier post they can really save.