Overview:

The Nuclear Regulatory Commission defines an advanced nuclear facility as “any nuclear facility for the production of electricity, the reactor design for which was approved after 1993.”

There are four main “advanced” nuclear reactor types in use globally. The primary differences among these various designs are the different concentrations of uranium used for fuel, the different moderators used to slow down the fission process, and different coolants used to transfer heat. [i]

The Generation III and IV light water reactor (LWRs), of which there are two—pressurized water reactor and boiling water reactor—is the most commonly used “advanced” nuclear reactor.

However, labeling this reactor as advanced is a misclassification as the reactor is so costly and slow to produce that they save 2–20 times less carbon and are approximately 20–40 times slower than micro power and efficient end-use.

As this becomes evident, other kinds of reactors are being proposed instead—novel designs that claim to solve LWRs’ problems of economics, proliferation, and waste. Even climate-protection pioneer, Jim Hansen, says these “Generation IV” reactors merit rapid R&D.

Upon closer examination, the three most often promoted alternate “advanced” reactors—integrated fast reactors (IFRs), thorium reactors, and small modular reactors—reveal no economic, environmental, or security advancements, and proceeding with any would be irresponsible.

Integrated Fast Reactors (IFRs)

IFRs—a pool -type, liquid-sodium cooled fast-neutron reactor (also known as fast breeder reactors)—was abandoned in 1994, due to proliferation concerns and untenable economics. Federal funding for these reactors halted in 1983, but in the past few years, enthusiasts received renewed support from the Bush Administration by portraying IFRs as a solution to proliferation and nuclear waste, completely disregarding previous findings to the contrary.

Fast breeder reactors were first offered as a way to increase plutonium production to supplement and ultimately replace scarce uranium. Now that uranium and enrichment are known to be less expensive than reprocessing, cleanup, and nonproliferation, IFRs have been reframed as a way to destroy or “burn up” the plutonium (and similar transuranic elements) in long-lived radioactive waste, making its “time of concern . . . less than 500 years” rather than 10,000–100,000 years or more.

However, this is false because the waste of nuclear fission produces the most radioactivity, including highly radioactive isotopes like iodine- 129 and technicium-99, and is broadly similar in any nuclear fuel cycle regardless of the reactor type.

Reprocessing of any kind makes waste management more difficult and complex by increasing the volume and diversity of waste streams and the cost of nuclear fueling, and separates bomb usable material that can’t be adequately measured or protected.

Over the past half century, the world’s leading nuclear technologists have built about three dozen fast breeder reactors. Of the twenty-two whose histories have been reported, over half had sodium leaks, four suffered fuel damage (including two partial meltdowns), several others had serious accidents, most were prematurely closed, and only six succeeded.

IFR programs have been attempted in the US, UK, France, Germany, Italy, Japan, and the USSR. All have failed.

After a half-century and tens of billions of dollars, the world has one operational commercial-sized fast reactor (Russia’s BN600) out of 438 commercial power reactors, and it’s not fueled with plutonium.

Thorium Reactors

Other nuclear enthusiasts believe fueling reactors with thorium is an “advanced” method that could be safer, more economical, and produce less waste than LWRs. Thorium is an element three times as abundant as uranium, but because of the many safety risks associated with using thorium as reactor fuel, it is significantly less economical to use than uranium.

Additionally, thorium-232 is not fissile, and as such cannot fuel a reactor by itself—it requires significant amounts of fissile materials (i.e. plutonium-239 or uranium-235) to generate the neutrons necessary for transmute some of the thorium to uranium-233, which poses significant proliferation risks.

Research and development of several reactor types was launched with the goal of demonstrating that uranium-233 derived from thorium would be a safe and economical source of electricity. The first commercial nuclear plant to utilize thorium was Indian Point Unit I, a pressurized water reactor that began operation in 1962. However, the cost of recovering uranium-233 from this reactor was described as a “financial disaster.” Less than one percent of the irradiated thorium was converted to uranium-233.

After hundreds of events involving equipment failure, gas leaks, fuel failures, cracked piping and graphite, and human error—most notably the Elk River Reactor in Minnesota, the Molten Salt Reactor at ORNL, and the light water breeder reactor at Shippingport, Pennsylvania—the pursuit of the thorium fuel cycle was effectively abandoned in 1977.

Thorium has proven to pose greater safety concerns, to be less economical, and to be thirteen times more radioactive than the uranium used in LWRs.

India’s decades of failed attempts to commercialize thorium fuel in their nuclear reactors to exploit its thorium deposits along with the United States’ proven failures with thorium reactors is evidence enough that it is impossible to sustainably resuscitate this “advanced” reactor design because the technology is not viable.

Small Modular Reactors

Westinghouse/Toshiba and Areva heralded small modular reactors as the foundation upon which the “nuclear renaissance” would be built. This “cutting edge technology” would be so commercially and economically viable that it could be mass produced in factory-like conditions.

Fortunately, both companies recently realized that small modular reactors (smaller iterations of pressure water reactors that produce less than 300 megawatts of electrical output—a fraction of the 1,000 megawatts produced by a typical commercial-scale reactor) are plagued with the same problems as large-scale nuclear reactors, such as: high production costs, the possibility of proliferation, and highly radioactive nuclear waste. After extensive research and development, no SMR designs to date have been approved.

The notion that “advanced” or smaller reactors could overcome nuclear energy’s inherent problems is ill-conceived. “Advanced” reactors have proven to simply be theoretical reactors—reactors that theoretically should work, but have no practical application. The aforementioned designs exist in theory only because they are unable to be successfully implemented and brought to commercial operation, despite the billions of dollars and decades that have been invested in researching and developing their feasibility, forestalling much faster and cheaper climate solutions.

Every new type of reactor introduced throughout history has been costlier, slower, and more difficult to produce than projected. Further proving our money and resources would be better spent on developing greater energy efficiency and affordable, safe renewable energy sources that are available now.