March 10, 2008

Energy - Nuclear power

There is a long-standing public concern about the safety of nuclear energy, though more people are realizing that it may be the most environmentally friendly way to generate large amounts of electricity. Several nations, including Brazil, China, Egypt, Finland, India, Japan, Pakistan, Russia, South Korea and Vietnam, are building or planning nuclear plants. But this global trend has not as yet extended to the U.S., where work on the last such facility began some 30 years ago.

The Fuel Cycle

The Open fuel cycle is the process when the uranium is "burned" once in a reactor, and spent fuel is stored in geologic repositories. The spent fuel includes plutonium that could be chemically extracted and turned into fuel for use in another nuclear plant. Doing that results in a closed fuel cycle, which some people advocate [see "Smarter Use of Nuclear Waste," by William H. Hannum, Gerald E. Marsh and George S. Stanford; Scientific American, December 2005].

France, currently use a closed fuel cycle in which plutonium is separated from the spent fuel and a mixture of plutonium and uranium oxides is subsequently burned again. A longer-term option could involve recycling all the transuranics (plutonium is one example of a transuranic element), perhaps in a so-called fast reactor. The open cycle is to be preferred over the next several decades.

First, the recycled fuel is more expensive than the original uranium. Second, there appears to be ample uranium at reasonable cost to sustain the tripling in global nuclear power generation that we envisage with a once-through fuel cycle for the entire lifetime of the nuclear fleet (about 40 to 50 years for each plant).

Third, the environmental benefit for long-term waste storage is offset by near-term risks to the environment from the complex and highly dangerous reprocessing and fuel-fabrication operations. Finally, the reprocessing that occurs in a closed fuel cycle produces plutonium that can be diverted for use in nuclear weapons.

Generation III reactors incorporate design improvements such as better fuel technology and passive safety, meaning that in the case of an accident the reactor shuts itself down without requiring the operators to intervene. The first generation III reactor was built in Japan in 1996.


Reducing the cost of capital for a nuclear plant to be the same as for a gas or coal plant would close the gap with coal (4.2 cents per kilowatt-hour). All these reductions in the cost of nuclear power are plausible--particularly if the industry builds a large number of just a few standardized designs--but not yet proved. Nuclear power becomes distinctly favored economically if carbon emissions are priced.


Most U.S. waste is currently stored in temporary storage sites requiring oversight, while suitable permanent disposal methods are discussed.

It has been argued that the best solution for the nuclear waste is above ground temporary storage since technology is rapidly changing. The current waste may well become a valuable resource in the future.

Finland is the first country to build a permanent storage site for its high-level nuclear waste. Yucca Mountain in Nevada has been a site considered for waste but it is unlikely it will be accepting waste before 2015 -this may complicate efforts to construct new power plants.

France is one of the world's most densely populated countries. According to a 2007 story broadcast on 60 Minutes, nuclear power gives France the cleanest air of any industrialized country, and the cheapest electricity in all of Europe. France reprocesses its nuclear waste to reduce its mass and make more energy. However, the article continues, "Today we stock containers of waste because currently scientists don't know how to reduce or eliminate the toxicity, but maybe in 100 years perhaps scientists will.

Fly ash—a by-product from burning coal for power—contains up to 100 times more radiation than nuclear waste. Fly ash uranium sometimes leaches into the soil and water surrounding a coal plant, affecting cropland and, in turn, food. People living within a "stack shadow"—the area within a half- to one-mile (0.8- to 1.6-kilometer) radius of a coal plant's smokestacks—might then ingest small amounts of radiation. Fly ash is also disposed of in landfills and abandoned mines and quarries, posing a potential risk to people living around those areas.

The result: estimated radiation doses ingested by people living near the coal plants were equal to or higher than doses for people living around the nuclear facilities. And when all food was grown in the area, radiation doses were 50 to 200 percent higher around the coal plants.

Radiation from uranium in coal might only form a genuine health risk to miners, Finkelman explains. "It's more of an occupational hazard than a general environmental hazard," he says. "The miners are surrounded by rocks and sloshing through ground water that is exuding radon."

After 40 years, the radiation flux is 99.9% lower than it was the moment the spent fuel was removed, although still dangerously radioactive.

Contrary to popular belief, coal power actually results in more radioactive waste being released into the environment than nuclear power. The population effective dose equivalent from radiation from coal plants is 100 times as much as nuclear plants.


Nuclear power plants use copious amounts of water for cooling. (which remains uncontaminated by radioactivity). The emitted water either is sent into cooling towers where it goes up and is emitted as water droplets (literally a cloud) or is discharged into large bodies of water - cooling ponds, lakes, rivers, or oceans. Droughts can pose a severe problem by causing the source of cooling water to run out.

Global Nuclear Energy Partnership (GNEP), announced by United States Department of Energy Secretary Samuel Bodman on February 6, 2006, is a plan to form an international partnership to reprocess spent nuclear fuel in a way that renders the plutonium in it usable for nuclear fuel but not for nuclear weapons. The plan is part of the Advanced Energy Initiative announced by President Bush in his 2006 State of the Union address.

The Department of Energy said:

The Global Nuclear Energy Partnership has four main goals. First, reduce America’s dependence on foreign sources of fossil fuels and encourage economic growth. Second, recycle nuclear fuel using new proliferation-resistant technologies to recover more energy and reduce waste. Third, encourage prosperity growth and clean development around the world. And fourth, utilize the latest technologies to reduce the risk of nuclear proliferation worldwide.

United States-Japan Joint Nuclear Energy Action Plan

It is a bilateral agreement aimed at putting in place a framework for the joint research and development of nuclear energy technology. The agreement was signed on April 18, 2007. The United States and Japan will each conduct research in to fast reactor technology, fuel cycle technology, advanced computer simulation and modeling, small and medium reactors, safeguards and physical protection; and nuclear waste management. The work is to be coordinated by a joint steering committee. An initial report on progress is due in April 2008.



Nuclear Power Reborn By David Biello

Coal Ash Is More Radioactive than Nuclear Waste By Mara Hvistendahl

Smarter Use of Nuclear Waste By William H. Hannum, Gerald E. Marsh and George S. Stanford

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