March 17, 2008 | 1 Comment
Technology that encapsulates atomic fuel first conceived and researched as early as the 1950s at the Oakridge National Laboratory and in partnership with West German teams has re-emerged and recovered to levels approximate to the best achieved in the 1960s by the West German teams. Today’s efforts lead by the Idaho National Laboratory with members Babcock and Wilcox Company, General Atomics and the Oak Ridge National Laboratory goes beyond the West German nuclear program that began the “pebble fuel” effort that has led to the “passive safe” design that is planned to be part of the next generation of atomic fission designs. The press release is based on a 9 percent fuel burnup achievement, not quite doubling the best fuel systems in use today, with 12-14% due to be achieved yet this year.
The technology is about the coatings that are applied to particles of fuel. Two paths are being followed, one is a cylinder shaped pellet of particles and the other is the pebble or spherical shaped pellet. The choices are made due to the diverging engineering sets that are going to pebbles that are entered into a fuel system and reside until burned through and rods filled with cylindrical pellets in common use today. The paths exist to accommodate the helium-cooled reactor where the helium gas is used to transfer the heat out to the electrical generation plant.
Spherical pellets are planned for use in systems that would meter through the fuel so avoiding a full shutdown to refuel. Cylindrical pellets would be used in rods that would produce larger reactors while still requiring a shutdown to refuel.
The advantages of the research and development of coating technology offers more beyond the increase of burnup percentage. The effects yield that the total fuel used is reduced, the amount needed to produce a given output is reduced and most importantly, the operating temperatures can be raised which brings a dramatic increase in the efficiency, or much more electricity is generated for a given amount of fuel. Nevertheless, the main concern for utility owners and customers is the safety increases as the coatings are stable beyond the reactive temperatures of the active fuel so blanking the “meltdown” or being a rich deposit of fuel that could be made into weapons.
The technique that forms the success that triggered the news release is based on micro sized fuel particles that are coated in successive layers of carbon and silicon layers that are compiled into cylinders that are harmless to handle prior to ignition. Its a result of reverse engineering the successful technology developed by the Germans for this fuel in the 1980s using carbon and silicon carbide layers. No micro sized photograph is available from the Idaho National Laboratory, but the Oakridge Laboratory shows the following sphere (Circa 2002):
Oakridge’s review offers that the increase in operating temperature would allow an increase of thermal efficiency from 31% of current plants to beyond 43% which equates to more than 38% more power should current plants be retrofitted. It may be probable that as plants are re-licensed with new reactor technology that new reactor designs are installed.
Oakridge is also suggesting that costs could get lower for new reactor designs. With international support the “International Reactor Innovative and Secure” (IRIS) design could get priced as low as $1000.USD (in 2002 dollars) per kilowatt, a dramatic reduction in installed expense.
The range of participants is getting quite large both in the number of countries involved and the companies participating. The interest from utilities is increasing and the political climate might be improving. There is a long way to go to satisfy the needs of the array of parties that believe they have rights to determine what we’ll pay for electrical power. But reports show the American ratepayer is sharp enough to know that smart design from decades of experience have formed an industry that can provide a safe and environmentally clean way to power modern life.
What is most encouraging is the two paths to better atomic fission in the fuel itself and the reactors that are more efficient, safer and less dangerous. Research is well under way for more efficient use of the heat released beyond the electrical generation stage. The nuclear power industry is headed for a boom. One just wonders how long it will take for the political class and the mass media to catch on to the facts and get wide based support underway.