Idaho National Laboratory scientists envision nuclear reactors that will work more efficiently, produce less waste, and can be used for other industrial applications.

Significantly avoiding carbon dioxide (CO2) emissions on a global scale has become a goal for nearly every industrialized nation. Generation IV nuclear reactors, which have been under development since 2000, offer promising new technologies that will help the United States reach this goal. “Nuclear energy is already the biggest noncarbon-emitting source of electricity we have in the United States,” said Ralph Bennett, a nuclear engineer and director of international and regional partnerships at Idaho National Laboratory (INL) in Idaho Falls, Idaho. “Advances to a fourth generation of nuclear energy will take 20 years or more, but hold tremendous potential for helping meet CO2 reductions at mid-century.”

U.S. Department of Energy (DOE) laboratories and universities are at the forefront of research and development on Generation IV—the name for the effort to advance the next generation of commercial nuclear reactor designs. Generation IV reactors are considered to be a revolutionary departure from previous designs. Advanced light water reactors are on the verge of deployment around the world. They are evolutionary designs with improved safety and performance features derived from more than 40 years of experience with commercial light water reactors. Generation IV designs employ technologies that extend performance and fuel efficiency beyond that which can ordinarily be achieved with light water reactors. These new designs will allow clean, safe nuclear power to play a larger role in our nation’s energy mix and support hybrid systems that include clean coal and renewable energy sources.

Six reactor concepts are currently being studied by teams of international experts as part of the Generation IV International Forum. The DOE will likely narrow these down to two Generation IV designs over the next 15 to 20 years to serve as models for the next reactor fleet. In the near term, the most promising new design appears to be a gas-cooled reactor dubbed the Very High Temperature Reactor. It could ultimately reach operating temperatures of 1000 degrees Celsius, hot enough to power many industrial processes. Today’s existing reactors use water as a coolant and heat to just over 300 degrees Celsius. Despite these high temperatures, gas reactors are extremely safe. Among other features, they employ a fuel design that is incredibly resistant to heat and radiation damage.

The first commercial deployment of a high-temperature gas reactor is the goal of the DOE’s Next Generation Nuclear Plant (NGNP) initiative. This technology will provide industries with a clean source of process heat to power most product applications. Many conventional industrial processes, such as oil refining, water treatment, fertilizer production and plastics manufacturing, require large amounts of hydrogen and very high temperatures. Hydrogen and heat are produced by burning natural gas that could be more effectively used to heat homes and power low-emission vehicles. Today hydrogen production alone accounts for about 7 percent of the natural gas used in the United States. About half of that hydrogen is used to produce ammonia for fertilizers, the other half to sweeten crude oil. Hydrogen fuel cells may be years away from large-scale deployment, but hydrogen production has always been an essential process in modern manufacturing and the production of agricultural products.

Finally, and perhaps most importantly, high-temperature reactors can also be used to cleanly extract our nation’s enormous oil reserves that are trapped in rock formations and cleanly convert even the most unattractive coal forms into high-quality transportation fuels, gas and the full spectrum of petroleum-based products. All of this, Bennett explained, could go a long way toward meeting the country’s goal for CO2 reductions, assuring energy independence and creating millions of new jobs in domestic energy supply and manufacturing.

NGNP is a deployment-oriented project that will enable commercialization of this technology within 8 to 10 years. Already in late 2008, an engineering team from INL, Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, Argonne National Laboratory in DuPage County, Illinois; and associated universities has achieved significant milestones in testing the fuel forms used in hightemperature gas-cooled reactor designs. Using multiple encapsulated fuel particles that were designed and manufactured in the United States and irradiated in INL’s Advanced Test Reactor, a record-setting 13 percent fuel burn up was achieved without any fuel failures. This greatly exceeds the 3 to 4 percent burnup currently experienced in existing light water reactors. INL, ORNL and commercial fuel fabricators are also working on carbon-based fuel cladding that is extremely resistant to heat damage.

“We could be getting about three times the energy out of the uranium with these new fuel forms,” said David Petti, a nuclear engineer and INL director of the Very High Temperature Reactor Technology Development. “The integrity of the individual fuel particle in the reactor has historically been the first line of defense in reactor safety so for us, these new ‘super fuels’ are very exciting developments with enormous potential to improve power, efficiency and lifetime of our new and operating commercial reactors. What’s more satisfying is that they were developed in the United States by teams of experts from the DOE, the National Laboratories, universities and the commercial nuclear industry.”

Also key to the Generation IV program are reactor designs that extract the residual energy of used light water fuel to make power, produce new fuel and render the original fuel far less radioactive than when it went into the reactor. This form of fuel recycling is clearly the focus of all responsible nations capable of advanced nuclear power systems design. It effectively turns today’s nuclear waste into tomorrow’s clean energy supply and makes nuclear power an almost endlessly renewable energy source.

Significant international research collaborations for Generation IV technology are ongoing, with more than half a billion dollars in collaborations committed over the next 5 years. France is pushing to have a Generation IV reactor built and operating as early as 2020; Japan, China and Russia have similar objectives. The United States may be ready to deploy a Generation IV reactor within 20 years; however, the level of support for this program is significantly less in the United States than in any of these other major program contributors..

It is frequently noted that there is no single answer to meeting our nation’s energy needs. This reflects the fact that unlike many nations, the United States has many options from which to choose. Technology advancements, hybrid energy systems that integrate historically competitive technologies, smart grid, distributed generation and conservation all must be part of the solution. However, any realistically achievable energy policy must include nuclear power as a base-load energy source. Almost 40 years of operating experience has unquestionably demonstrated nuclear power’s safety, reliability and efficiency.