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Saturday, June 5, 2021

Energy Policy Act of 2005

From Wikipedia, the free encyclopedia
 
George W. Bush signing the Energy Policy Act of 2005, which was designed to promote US nuclear reactor construction, through incentives and subsidies, including cost-overrun support up to a total of $2 billion for six new nuclear plants.

The Energy Policy Act of 2005 (Pub.L. 109–58 (text) (pdf)) is a federal law signed by President George W. Bush on August 8, 2005, at Sandia National Laboratories in Albuquerque, New Mexico. The act, described by proponents as an attempt to combat growing energy problems, changed US energy policy by providing tax incentives and loan guarantees for energy production of various types. The law also exempted hydraulic fracturing fluids from regulation under several environmental laws, and it repealed the Public Utility Holding Company Act of 1935, effective February 2006.

Provisions

General provisions

  • The law exempted fluids used in the natural gas extraction process of hydraulic fracturing (fracking) from protections under the Clean Air Act, Clean Water Act, Safe Drinking Water Act, and CERCLA ("Superfund").
  • Under an amendment in the American Recovery and Reinvestment Act of 2009, Section 406, the Energy Policy Act of 2005 authorizes loan guarantees for innovative technologies that avoid greenhouse gases, which might include advanced nuclear reactor designs, such as pebble bed modular reactors (PBMRs) as well as carbon capture and storage and renewable energy;
  • the Act increases the amount of biofuel (usually ethanol) that must be mixed with gasoline sold in the United States to 4 billion US gallons (15,000,000 m3) by 2006, 6.1 billion US gallons (23,000,000 m3) by 2009 and 7.5 billion US gallons (28,000,000 m3) by 2012; two years later, the Energy Independence and Security Act of 2007 extended the target to 36 billion US gallons (140,000,000 m3) by 2022.
  • it seeks to increase coal as an energy source while also reducing air pollution, through authorizing $200 million annually for clean coal initiatives, repealing the current 160-acre (0.65 km2) cap on coal leases, allowing the advanced payment of royalties from coal mines and requiring an assessment of coal resources on federal lands that are not national parks;
  • it authorizes tax credits for wind and other alternative energy producers;
  • it adds ocean energy sources, including wave and tidal power for the first time as separately identified, renewable technologies;
  • it authorizes $50 million annually over the life of the law for biomass grants;
  • it includes provisions aimed at making geothermal energy more competitive with fossil fuels in generating electricity;
  • it requires the Department of Energy to:
  • it authorizes the Department of the Interior to grant leases for activity that involves the production, transportation or transmission of energy on the Outer Continental Shelf lands from sources other than gas and oil (Section 388);
  • it requires all public electric utilities to offer net metering on request to their customers;
  • it prohibits the manufacture and importation of mercury-vapor lamp ballasts after January 1, 2008;
  • it provides tax breaks for those making energy conservation improvements to their homes;
  • it provides incentives to companies to drill for oil in the Gulf of Mexico;
  • it exempts oil and gas producers from certain requirements of the Safe Drinking Water Act;
  • it extends the daylight saving time by four to five weeks, depending upon the year (see below);
  • it requires that no drilling for gas or oil may be done in or underneath the Great Lakes;
  • it requires that the Federal Fleet vehicles capable of operating on alternative fuels be operated on these fuels exclusively (Section 701);
  • it sets federal reliability standards regulating the electrical grid (done in response to the 2003 North America blackout);
  • it includes nuclear-specific provisions;
    • it extends the Price-Anderson Nuclear Industries Indemnity Act through 2025;
    • it authorizes cost-overrun support of up to $2 billion total for up to six new nuclear power plants;
    • it authorizes production tax credit of up to $125 million total a year, estimated at 1.8 US¢/kWh during the first eight years of operation for the first 6.000 MW of capacity, consistent with renewables;
    • it authorizes loan guarantees of up to 80% of project cost to be repaid within 30 years or 90% of the project's life;
    • it authorizes $2.95 billion for R&D and the building of an advanced hydrogen cogeneration reactor at Idaho National Laboratory;
    • it authorizes 'standby support' for new reactor delays that offset the financial impact of delays beyond the industry's control for the first six reactors, including 100% coverage of the first two plants with up to $500 million each and 50% of the cost of delays for plants three through six with up to $350 million each for;
    • it allows nuclear plant employees and certain contractors to carry firearms;
    • it prohibits the sale, export or transfer of nuclear materials and "sensitive nuclear technology" to any state sponsor of terrorist activities;
    • it updates tax treatment of decommissioning funds;
  • it directs the Secretary of the Interior to complete a programmatic environmental impact statement for a commercial leasing program for oil shale and tar sands resources on public lands with an emphasis on the most geologically prospective lands within each of the states of Colorado, Utah, and Wyoming.

Tax reductions by subject area

Change to daylight saving time

The law amended the Uniform Time Act of 1966 by changing the start and end dates of daylight saving time, beginning in 2007. Clocks were set ahead one hour on the second Sunday of March (March 11, 2007) instead of on the first Sunday of April (April 1, 2007). Clocks were set back one hour on the first Sunday in November (November 4, 2007), rather than on the last Sunday of October (October 28, 2007). This had the net effect of slightly lengthening the duration of daylight saving time.

Lobbyists for this provision included the Sporting Goods Manufacturers Association, the National Association of Convenience Stores, and the National Retinitis Pigmentosa Foundation Fighting Blindness.

Lobbyists against this provision included the U.S. Conference of Catholic Bishops, the United Synagogue of Conservative Judaism, the National Parent-Teacher Association, the Calendaring and Scheduling Consortium, the Edison Electric Institute, and the Air Transport Association. This section of the act is controversial; some have questioned whether daylight saving results in net energy savings.

Commercial building deduction

The Act created the Energy Efficient Commercial Buildings Tax Deduction, a special financial incentive designed to reduce the initial cost of investing in energy-efficient building systems via an accelerated tax deduction under section §179D of the Internal Revenue Code (IRC) Many building owners are unaware that the [Policy Act of 2005] includes a tax deduction (§179D) for investments in "energy efficient commercial building property" designed to significantly reduce the heating, cooling, water heating and interior lighting cost of new or existing commercial buildings placed into service between January 1, 2006 and December 31, 2013. §179D includes full and partial tax deductions for investments in energy efficient commercial building that are designed to increase the efficiency of energy-consuming functions. Up to $.60 for lighting, $.60 for HVAC and $.60 for building envelope, creating a potential deduction of $1.80 per sq/ft. Interior lighting may also be improved using the Interim Lighting Rule, which provides a simplified process to earn the Deduction, capped at $0.30-$0.60/square foot. Improvements are compared to a baseline of ASHRAE 2001 standards.

To obtain these benefits the facilities/energy division of a business, its tax department, and a firm specializing in EPAct 179D deductions needed to cooperate. IRS mandated software had to be used and an independent 3rd party had to certify the qualification. For municipal buildings, benefits were passed through to the primary designers/architects in an attempt to encourage innovative municipal design.

The Commercial Buildings Tax Deduction expiration date had been extended twice, last by the Energy Improvement and Extension Act of 2008. With this extension, the CBTD could be claimed for qualifying projects completed before January 1, 2014.

Energy management

The commercial building tax deductions could be used to improve the payback period of a prospective energy improvement investment. The deductions could be combined by participating in demand response programs where building owners agree to curtail usage at peak times for a premium. The most common qualifying projects were in the area of lighting.

Energy savings

Summary of Energy Savings Percentages Provided by IRS Guidance

Percentages permitted under Notice 2006-52 (Effective for property placed in service January 1, 2006 – December 31, 2008)

  • Interior Lighting Systems 16⅔%,
  • Heating, Cooling, Ventilation, and Hot Water Systems 16⅔%,
  • Building Envelope 16⅔%.

Percentages permitted under Notice 2008-40 (Effective for property placed in service January 1, 2006 – December 31, 2013)

  • Interior Lighting Systems 20%,
  • Heating, Cooling, Ventilation, and Hot Water Systems 20%,
  • Building Envelope 10%.

Percentages permitted under Notice 2012-22

  • Interior Lighting Systems 25%,
  • Heating, Cooling, Ventilation, and Hot Water Systems 15%,
  • Building Envelope 10%.

Effective date of Notice 2012-22 – December 31, 2013; if §179D is extended beyond December 31, 2013, is also effective (except as otherwise provided in an amendment of §179D or the guidance thereunder) during the period of the extension.

Cost estimate

The Congressional Budget Office (CBO) review of the conference version of the bill estimated the Act would increase direct spending by $2.2 billion over the 2006-2010 period, and by $1.6 billion over the 2006-2015 period. The CBO did not attempt to estimate additional effects on discretionary spending. The CBO and the Joint Committee on Taxation estimated that the legislation would reduce revenues by $7.9 billion over the 2005-2010 period and by $12.3 billion over the 2005-2015 period.

Support

The collective reduction in national consumption of energy (gas and electricity) is significant for home heating. The Act provided gible financial incentives (tax credits) for average homeowners to make environmentally positive changes to their homes. It made improvements to home energy use more affordable for walls, doors, windows, roofs, water heaters, etc. Consumer spending, and hence the national economy, was abetted. Industry grew for manufacture of these environmentally positive improvements. These positive improvements have been near and long-term in effect.

The collective reduction in national consumption of oil is significant for automotive vehicles. The Act provided tangible financial incentives (tax credits) for operators of hybrid vehicles. It helped fuel competition among auto makers to meet rising demands for fuel-efficient vehicles. Consumer spending, and hence the national economy, was abetted. Dependence on imported oil was reduced. The national trade deficit was improved. Industry grew for manufacture of these environmentally positive improvements. These positive improvements have been near and long-term in effect.

Criticism

  • The Washington Post contended that the spending bill was a broad collection of subsidies for United States energy companies; in particular, the nuclear and oil industries.
  • Speaking for the National Republicans for Environmental Protection Association, President Martha Marks said that the organization was disappointed in the law because it did not support conservation enough, and continued to subsidize the well-established oil and gas industries that didn't require subsidizing.
  • The law did not include provisions for drilling in the Arctic National Wildlife Refuge (ANWR); some Republicans claimed "access to the abundant oil reserves in ANWR would strengthen America's energy independence without harming the environment."
  • Senator Hillary Clinton criticized Senator Barack Obama's vote for the bill in the 2008 Democratic Primary.
  • The law exempted fluids used in the natural gas extraction process of hydraulic fracturing (fracking) from protections under the Clean Air Act, Clean Water Act, Safe Drinking Water Act, and CERCLA. It created a loophole that exempts companies drilling for natural gas from disclosing the chemicals involved in fracking operations that would normally be required under federal clean water laws. This exclusion has been called the "Halliburton Loophole". Halliburton is the world's largest provider of hydraulic fracturing services. The measure was a response to a recommendation from the Energy Task Force, chaired by Vice President Dick Cheney in 2001. (Cheney had been Chairman and CEO of Halliburton from 1995 to 2000.)

Legislative history

The Act was voted on and passed twice by the United States Senate, once prior to conference committee, and once after. In both cases, there were numerous senators who voted against the bill. John McCain, the Republican Party nominee for President of the United States in the 2008 election voted against the bill. Democrat Barack Obama, President of the United States from January 2009 to January 2017, voted in favor of the bill.

Provisions in the original bill that were not in the act

To remove from 18 CFR Part 366.1 the definitions of "electric utility company" and exempt wholesale generator (EWG), that an EWG is not an electric utility company.

Preliminary Senate vote

June 28, 2005, 10:00 a.m. Yeas - 85, Nays - 12

Conference committee

The bill's conference committee included 14 Senators and 51 House members. The senators on the committee were: Republicans Domenici, Craig, Thomas, Alexander, Murkowski, Burr, Grassley and Democrats Bingaman, Akaka, Dorgan, Wyden, Johnson, and Baucus.

Final Senate vote

July 29, 2005, 12:50 p.m. Yeas - 74, Nays - 26

Legislative history

Energy Policy Act of 2005
Great Seal of the United States
Other short titles
  • Coal Leasing Amendments Act of 2005
  • Electricity Modernization Act of 2005
  • Energy Policy Tax Incentives Act of 2005
  • Energy Research, Development, Demonstration, and Commercial Application Act of 2005
  • Energy Tax Incentives Act of 2005
  • Federal Reformulated Fuels Act of 2005
  • Indian Tribal Energy Development and Self-Determination Act of 2005
  • EPAct 2005
  • John Rishel Geothermal Steam Act Amendments of 2005
  • National Geological and Geophysical Data Preservation Program Act of 2005
  • No Oil Producing and Exporting Cartels Act of 2005
  • NOPEC
  • Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005
  • Price-Anderson Amendments Act of 2005
  • Public Utility Holding Company Act of 2005
  • SAFE Act
  • Set America Free Act of 2005
  • Spark M. Matsunaga Hydrogen Act of 2005
  • Underground Storage Tank Compliance Act
Long titleAn Act to ensure jobs for our future with secure, affordable, and reliable energy.
Enacted bythe 109th United States Congress
EffectiveAugust 8, 2005
Citations
Public law109-58
Statutes at Large119 Stat. 594
Codification
Acts amendedEnergy Policy Act of 1992
Public Utility Regulatory Policies Act (PURPA) of 1978
Acts repealedPublic Utility Holding Company Act of 1935
Titles amended16 U.S.C.: Conservation
42 U.S.C.: Public Health and Social Welfare
U.S.C. sections created42 U.S.C. ch. 149 § 15801 et seq.
U.S.C. sections amended16 U.S.C. ch. 46 § 2601 et seq.
42 U.S.C. ch. 134 § 13201 et seq.
Legislative history
Major amendments
American Recovery and Reinvestment Act of 2009
Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010
Stage House of Representatives Senate
Initial Debate
Introduction April 18, 2005 June 11
Committed April 18 June 14
Committee Name(s) Energy and Commerce
Education and the Workforce
Financial Services
Agriculture
Resources
Science
Ways and Means
Transportation and Infrastructure
Committee Stage April 18 to 19
Committee Report April 19
Floor Debate April 19 to 21 June 14 to 23

Cloture invoked June 23,

Passage April 21, June 28,
Conference Stage
Conference Demanded/Accepted July 13 July 1
Conference Meetings July 14 to 24
Report Filed July 27
Final Passage
Final Debate July 28 July 28 to 29
Budget Act waived, July 29,
Concurrence and Passage July 28 July 29
Presented to President August 4
Signed August 8

 

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Nuclear renaissance

From Wikipedia, the free encyclopedia
 
For miniatures wargame, see Nuclear Renaissance (wargame).
 
Timeline of commissioned and decommissioned nuclear capacity since 1970

Since about 2001 the term nuclear renaissance has been used to refer to a possible nuclear power industry revival, driven by rising fossil fuel prices and new concerns about meeting greenhouse gas emission limits.

In the 2009 World Energy Outlook, the International Energy Agency stated that:

A nuclear renaissance is possible but cannot occur overnight. Nuclear projects face significant hurdles, including extended construction periods and related risks, long licensing processes and manpower shortages, plus long‐standing issues related to waste disposal, proliferation and local opposition. The financing of new nuclear power plants, especially in liberalized markets, has always been difficult and the financial crisis seems almost certain to have made it even more so. The huge capital requirements, combined with risks of cost overruns and regulatory uncertainties, make investors and lenders very cautious, even when demand growth is robust.

The World Nuclear Association reported that nuclear electricity generation in 2012 was at its lowest level since 1999.

In 2015:

  • Ten new reactors were connected to the grid, the highest number since 1990, but expanding Asian nuclear programs are balanced by retirements of aging plants and nuclear reactor phase-outs.
  • Seven reactors were permanently shut down.
  • 441 operational reactors had a worldwide net capacity of 382,855 megawatts of electricity. However, some reactors are classified as operational, but are not producing any power.
  • 67 new nuclear reactors were under construction, including four EPR units. The first two EPR projects, in Finland and France, were meant to lead a nuclear renaissance but both are facing costly construction delays. Construction commenced on two Chinese EPR units in 2009 and 2010. The Chinese units were to start operation in 2014 and 2015, but the Chinese government halted construction because of safety concerns.

March 2017 saw a setback for nuclear renaissance when producer of the AP1000 reactor Westinghouse Electric Company filed for Chapter 11 bankruptcy protection. Four months later the bankruptcy together with delays and cost overruns caused cancellation of the two AP1000 reactors under construction at the Virgil C. Summer Nuclear Generating Station.

History

In 2009 annual generation of nuclear power has been on a slight downward trend since 2007, decreasing 1.8% in 2009 to 2558 TWh with nuclear power meeting 13–14% of the world's electricity demand. A major factor in the decrease has been the prolonged repair of seven large reactors at the Kashiwazaki-Kariwa Nuclear Power Plant in Japan following the Niigata-Chuetsu-Oki earthquake.

In March 2011 the nuclear accidents at Japan's Fukushima I Nuclear Power Plant and shutdowns at other nuclear facilities raised questions among some commentators over the future of the renaissance. Platts has reported that "the crisis at Japan's Fukushima nuclear plants has prompted leading energy-consuming countries to review the safety of their existing reactors and cast doubt on the speed and scale of planned expansions around the world". In 2011 Siemens exited the nuclear power sector following the Fukushima disaster and subsequent changes to German energy policy, and supported the German government's planned energy transition to renewable energy technologies. China, Germany, Switzerland, Israel, Malaysia, Thailand, United Kingdom, Italy and the Philippines have reviewed their nuclear power programs. Indonesia and Vietnam still plan to build nuclear power plants. Countries such as Australia, Austria, Denmark, Greece, Ireland, Latvia, Liechtenstein, Luxembourg, Portugal, Israel, Malaysia, New Zealand, and Norway remain opposed to nuclear power. Following the Fukushima I nuclear accidents, the International Energy Agency halved its estimate of additional nuclear generating capacity built by 2035.

The World Nuclear Association has reported that “nuclear power generation suffered its biggest ever one-year fall through 2012 as the bulk of the Japanese fleet remained offline for a full calendar year”. Data from the International Atomic Energy Agency showed that nuclear power plants globally produced 2346 TWh of electricity in 2012 – seven per cent less than in 2011. The figures illustrate the effects of a full year of 48 Japanese power reactors producing no power during the year. The permanent closure of eight reactor units in Germany was also a factor. Problems at Crystal River, Fort Calhoun and the two San Onofre units in the USA meant they produced no power for the full year, while in Belgium Doel 3 and Tihange 2 were out of action for six months. Compared to 2010, the nuclear industry produced 11% less electricity in 2012.

As of July 2013, "a total of 437 nuclear reactors were operating in 30 countries, seven fewer than the historical maximum of 444 in 2002. Since 2002, utilities have started up 28 units and disconnected 36 including six units at the Fukushima Daiichi nuclear power plant in Japan. The 2010 world reactor fleet had a total nominal capacity of about 370 gigawatts (or thousand megawatts). Despite seven fewer units operating in 2013 than in 2002, the capacity is still about 7 gigawatts higher". The numbers of new operative reactors, final shutdowns and new initiated constructions according to International Atomic Energy Agency (IAEA) in 2010 are as follows:

Overview

A total of 72 reactors were under construction at the beginning of 2014, the highest number in 25 years. Several of the under construction reactors are carry over from earlier eras; some are partially completed reactors on which work has resumed (e.g., in Argentina); some are small and experimental (e.g., Russian floating reactors); and some have been on the IAEA's “under construction” list for years (e.g., in India and Russia). Reactor projects in Eastern Europe are essentially replacing old Soviet reactors shut down due to safety concerns. Most of the 2010 activity ― 30 reactors ― is taking place in four countries: China, India, Russia and South Korea. Turkey, the United Arab Emirates and Iran are the only countries that are currently building their first power reactors, Iran's construction began decades ago.

Eight German nuclear power reactors (Biblis A and B, Brunsbuettel, Isar 1, Kruemmel, Neckarwestheim 1, Philippsburg 1 and Unterweser) were permanently shutdown on August 6, 2011, following the Japanese Fukushima nuclear disaster.

Various barriers to a nuclear renaissance have been suggested. These include: unfavourable economics compared to other sources of energy, slowness in addressing climate change, industrial bottlenecks and personnel shortages in the nuclear sector, and the contentious issue of what to do with nuclear waste or spent nuclear fuel. There are also concerns about more nuclear accidents, security, and nuclear weapons proliferation.

New reactors under construction in Finland and France, which were meant to lead a nuclear renaissance, have been delayed and are running over-budget. China has 22 new reactors under construction, and there are also a considerable number of new reactors being built in South Korea, India, and Russia. At the same time, at least 100 older and smaller reactors will "most probably be closed over the next 10–15 years". So the expanding nuclear programs in Asia are balanced by retirements of aging plants and nuclear reactor phase-outs.

A study by UBS, reported on April 12, 2011, predicts that around 30 nuclear plants may be closed worldwide, with those located in seismic zones or close to national boundaries being the most likely to shut. The analysts believe that 'even pro-nuclear countries such as France will be forced to close at least two reactors to demonstrate political action and restore the public acceptability of nuclear power', noting that the events at Fukushima 'cast doubt on the idea that even an advanced economy can master nuclear safety'. In September 2011, German engineering giant Siemens announced it will withdraw entirely from the nuclear industry, as a response to the Fukushima nuclear disaster in Japan.

The 2011 World Energy Outlook report by the International Energy Agency stated that having "second thoughts on nuclear would have far-reaching consequences" and that a substantial shift away from nuclear power would boost demand for fossil fuels, putting additional upward pressure on the price of energy, raising additional concerns about energy security, and making it more difficult and expensive to combat climate change. The reports suggests that the consequences would be most severe for nations with limited local energy resources and which have been planning to rely heavily on nuclear power for future energy security, and that it would make it substantially more challenging for developing economies to satisfy their rapidly increasing demand for electricity.

John Rowe, chair of Exelon (the largest nuclear power producer in the US), has said that the nuclear renaissance is "dead". He says that solar, wind and cheap natural gas have significantly reduced the prospects of coal and nuclear power plants around the world. Amory Lovins says that the sharp and steady cost reductions in solar power has been a "stunning market success".

In 2013 the analysts at the investment research firm Morningstar, Inc. concluded that nuclear power was not a viable source of new power in the West. On nuclear renaissance they wrote:

The economies of scale experienced in France during its initial build-out and the related strength of supply chain and labor pool were imagined by the dreamers who have coined the term ‘nuclear renaissance’ for the rest of the world. But outside of China and possibly South Korea this concept seems a fantasy, as should become clearer examining even theoretical projections for new nuclear build today.

Economics

Nuclear power plants are large construction projects with very high up-front costs. The cost of capital is also steep due to the risk of construction delays and obstructing legal action. The large capital cost of nuclear power has been a key barrier to the construction of new reactors around the world, and the economics have recently worsened, as a result of the global financial crisis. As the OECD's Nuclear Energy Agency points out, "investors tend to favor less capital intensive and more flexible technologies". This has led to a large increase in the use of natural gas for base-load power production, often using more sophisticated combined cycle plants.

Accidents and safety

Following the 2011 Japanese Fukushima nuclear disaster, authorities shut down the nation's 54 nuclear power plants. As of 2013, the Fukushima site remains highly radioactive, with some 160,000 evacuees still living in temporary housing, and some land will be unfarmable for centuries. The difficult cleanup job will take 40 or more years, and cost tens of billions of dollars.

Major nuclear reactor accidents include Three Mile Island accident (1979), Chernobyl disaster (1986), and Fukushima (2011). A report in Lancet says that the effects of these accidents on individuals and societies are diverse and enduring. Relatively few immediate deaths have occurred, but nuclear-related fatalities are mostly in the hazardous uranium mining industry, which supplies fuel to nuclear reactors. There are also physical health problems directly attributable to radiation exposure, as well as psychological and social effects. The Fukushima accident forced more than 80,000 residents to evacuate from neighborhoods around the crippled nuclear plant. Evacuation and long-term displacement create severe health-care problems for the most vulnerable people, such as hospital inpatients and elderly people.

Charles Perrow, in his book Normal accidents says that multiple and unexpected failures are built into complex and tightly coupled systems, such as nuclear power plants. Such accidents often involve operator error and are unavoidable and cannot be designed around. Since the terrorist attacks of September 11, 2001, there has been heightened concern that nuclear power plants may be targeted by terrorists or criminals, and that nuclear materials may be purloined for use in nuclear or radiological weapons.

Nevertheless, newer reactor designs intended to provide increased safety have been developed over time. The next nuclear plants to be built will likely be Generation III or III+ designs, and a few are being built in Japan. However, safety risks may be the greatest when nuclear systems are the newest, and operators have less experience with them. Nuclear engineer David Lochbaum explained that almost all serious nuclear accidents occurred with what was at the time the most recent technology. He argues that "the problem with new reactors and accidents is twofold: scenarios arise that are impossible to plan for in simulations; and humans make mistakes".

Controversy

A nuclear power controversy has surrounded the deployment and use of nuclear fission reactors to generate electricity from nuclear fuel for civilian purposes. The controversy peaked during the 1970s and 1980s, when it "reached an intensity unprecedented in the history of technology controversies", in some countries.

In 2008 there were reports of a revival of the anti-nuclear movement in Germany and protests in France during 2004 and 2007. Also in 2008 in the United States, there were protests about, and criticism of, several new nuclear reactor proposals and later some objections to license renewals for existing nuclear plants.

Public opinion

refer to caption and image description
Global public support for energy sources, based on a survey by Ipsos (2011) taken 2 months after the Fukushima Disaster.

In 2005, the International Atomic Energy Agency presented the results of a series of public opinion surveys in the Global Public Opinion on Nuclear Issues report. Majorities of respondents in 14 of the 18 countries surveyed believe that the risk of terrorist acts involving radioactive materials at nuclear facilities is high, because of insufficient protection. While majorities of citizens generally support the continued use of existing nuclear power reactors, most people do not favour the building of new nuclear plants, and 25% of respondents feel that all nuclear power plants should be closed down. Stressing the climate change benefits of nuclear energy positively influences 10% of people to be more supportive of expanding the role of nuclear power in the world, but there is still a general reluctance to support the building of more nuclear power plants. After the Fukushima Disaster, Civil Society Institute (CSI) found out that 58 percent of the respondents indicated less support of using nuclear power in the United States. Two-thirds of the respondents said they would protest the construction of a nuclear reactor within 50 miles of their homes.

There was little support across the world for building new nuclear reactors, a 2011 poll for the BBC indicates. The global research agency GlobeScan, commissioned by BBC News, polled 23,231 people in 23 countries from July to September 2011, several months after the Fukushima nuclear disaster. In countries with existing nuclear programmes, people are significantly more opposed than they were in 2005, with only the UK and US bucking the trend. Most believe that boosting energy efficiency and renewable energy can meet their needs.

By region and country

Africa

As of March 2010, ten African nations had begun exploring plans to build nuclear reactors.

South Africa (which has two nuclear power reactors), however, removed government funding for its planned new PBMRs in 2010.

America

United States

George W. Bush signing the Energy Policy Act of 2005, which was designed to promote US nuclear reactor construction, through incentives and subsidies, including cost-overrun support up to a total of $2 billion for six new nuclear plants.

Between 2007 and 2009, 13 companies applied to the Nuclear Regulatory Commission for construction and operating licenses to build 30 new nuclear power reactors in the United States. However, the case for widespread nuclear plant construction was eroded due to abundant natural gas supplies, slow electricity demand growth in a weak US economy, lack of financing, and uncertainty following the Fukushima nuclear disaster. Many license applications for proposed new reactors were suspended or cancelled. Only a few new reactors will enter service by 2020. These will not be the cheapest energy options available, but they are an attractive investment for utilities because the government mandates that taxpayers pay for construction in advance. In 2013, four aging, uncompetitive, reactors were permanently closed: San Onofre 2 and 3 in California, Crystal River 3 in Florida, and Kewaunee in Wisconsin. Vermont Yankee, in Vernon, is scheduled to close in 2014, following many protests. New York State is seeking to close Indian Point Energy Center, in Buchanan, 30 miles from New York City.

Neither climate change abatement, nor the Obama Administration's endorsement of nuclear power with $18.5 billion in loan guarantees, have been able to propel nuclear power in the US past existing obstacles. The Fukushima nuclear disaster has not helped either.

As of 2014, the U.S. nuclear industry began a new lobbying effort, hiring three former senators — Evan Bayh, a Democrat; Judd Gregg, a Republican; and Spencer Abraham, a Republican — as well as William M. Daley, a former staffer to President Obama. The initiative is called Nuclear Matters, and it has begun a newspaper advertising campaign.

Locations of new US reactors and their scheduled operating dates are:

  • Tennessee, Watts Bar unit 2 in operation since October 2016
  • Georgia, Vogtle Electric unit 3 planned to be operational 2021, unit 4 planned to be operational 2022

On 29 March 2017, parent company Toshiba placed Westinghouse Electric Company in Chapter 11 bankruptcy because of US$9 billion of losses from its nuclear reactor construction projects. The projects responsible for this loss are mostly the construction of four AP1000 reactors at Vogtle in Georgia and V. C. Summer in South Carolina. The U.S. government had given $8.3 billion of loan guarantees on the financing of the four nuclear reactors being built in the U.S. The plans at V. C. Summer have been cancelled, whereas construction at Vogtle continues. Peter A. Bradford, former U.S. Nuclear Regulatory Commission member, commented "They placed a big bet on this hallucination of a nuclear renaissance".

Asia

As of 2008, the greatest growth in nuclear generation was expected to be in China, Japan, South Korea and India.

As of early 2013 China had 17 nuclear reactors operating and 32 under construction, with more planned. "China is rapidly becoming self-sufficient in reactor design and construction, as well as other aspects of the fuel cycle." However, according to a government research unit, China must not build "too many nuclear power reactors too quickly", in order to avoid a shortfall of fuel, equipment and qualified plant workers.

Following the Fukushima disaster, many are questioning the mass roll-out of new plants in India, including the World Bank, the Indian Environment Minister, Jairam Ramesh, and the former head of the country's nuclear regulatory body, A. Gopalakrishnan. The massive Jaitapur Nuclear Power Project is the focus of concern – "931 hectares of farmland will be needed to build the reactors, land that is now home to 10,000 people, their mango orchards, cashew trees and rice fields". Fishermen in the region say their livelihoods will be wiped out.

South Korea is exploring nuclear projects with a number of nations.

Australia

Australia is a major producer of uranium, which it exports as uranium oxide to nuclear power generating nations. Australia has a single research reactor at Lucas Heights, but does not generate electricity via nuclear power. As of 2015, the majority of the nation's uranium mines are in South Australia, where a Nuclear Fuel Cycle Royal Commission is investigating the opportunities and costs of expanding the state's role in the nuclear fuel cycle. As of January 2016, new nuclear industrial development (other than the mining of uranium) is prohibited by various acts of federal and state legislation. The Federal government will consider the findings of the South Australian Royal Commission after it releases its findings in 2016.

Canada

With several CANDU reactors facing closure selected plants will be completely refurbished between 2016 and 2026, extending their operation beyond 2050.

Europe

EDF has said its third-generation EPR Flamanville 3 project (seen here in 2010) will be delayed until 2018, due to "both structural and economic reasons," and the project's total cost has climbed to EUR 11 billion in 2012. Similarly, the cost of the EPR being built at Olkiluoto, Finland has escalated dramatically, and the project is well behind schedule. The initial low cost forecasts for these megaprojects exhibited "optimism bias".

On 18 October 2010 the British government announced eight locations it considered suitable for future nuclear power stations. This has resulted in public opposition and protests at some of the sites. In March 2012, two of the big six power companies announced they would be pulling out of developing new nuclear power plants. The decision by RWE npower and E.ON follows uncertainty over nuclear energy following the Fukushima nuclear disaster last year. The companies will not proceed with their Horizon project, which was to develop nuclear reactors at Wylfa in North Wales and at Oldbury-on-Severn in Gloucestershire. Their decision follows a similar announcement by Scottish and Southern Electricity last year. Analysts said the decision meant the future of UK nuclear power could now be in doubt.

The 2011 Japanese Fukushima nuclear disaster has led some European energy officials to "think twice about nuclear expansion". Switzerland has abandoned plans to replace its old nuclear reactors and will take the last one offline in 2034. Anti-nuclear opposition intensified in Germany. In the following months the government decided to shut down eight reactors immediately (August 6, 2011) and to have the other nine off the grid by the end of 2022. Renewable energy in Germany is believed to be able to compensate for much of the loss. In September 2011 Siemens, which had been responsible for constructing all 17 of Germany's existing nuclear power plants, announced that it would exit the nuclear sector following the Fukushima disaster and the subsequent changes to German energy policy. Chief executive Peter Loescher has supported the German government's planned energy transition to renewable energy technologies, calling it a "project of the century" and saying Berlin's target of reaching 35% renewable energy sources by 2020 was feasible.

On October 21, 2013, EDF Energy announced that an agreement had been reached regarding new nuclear plants to be built on the site of Hinkley Point C. EDF Group and the UK Government agreed on the key commercial terms of the investment contract. The final investment decision is still conditional on completion of the remaining key steps, including the agreement of the EU Commission.

In February 2014, Amory Lovins commented that:

Britain's plan for a fleet of new nuclear power stations is … unbelievable ... It is economically daft. The guaranteed price [being offered to French state company EDF] is over seven times the unsubsidised price of new wind in the US, four or five times the unsubsidised price of new solar power in the US. Nuclear prices only go up. Renewable energy prices come down. There is absolutely no business case for nuclear. The British policy has nothing to do with economic or any other rational base for decision making.

Middle East

In December 2009 South Korea won a contract for four nuclear power plants to be built in the United Arab Emirates, for operation in 2017 to 2020.

On March 17, 2011, Israeli Prime Minister Benjamin Netanyahu stated that Israel was now unlikely to pursue civil nuclear energy.

Russia

In April 2010 Russia announced new plans to start building 10 new nuclear reactors in the next year.

Views and opinions

In June 2009, Mark Cooper from the Vermont Law School said: "The highly touted renaissance of nuclear power is based on fiction, not fact... There are numerous options available to meet the need for electricity in a carbon-constrained environment that are superior to building nuclear reactors".

In September 2009, Luc Oursel, chief executive of Areva Nuclear Plants (the core nuclear reactor manufacturing division of Areva) stated: "We are convinced about the nuclear renaissance". Areva has been hiring up to 1,000 people a month, "to prepare for a surge in orders from around the world". However, in June 2010, Standard & Poor's downgraded Areva's debt rating to BBB+ due to weakened profitability.

In 2010, Trevor Findlay from the Centre for International Governance Innovation stated that "despite some powerful drivers and clear advantages, a revival of nuclear energy faces too many barriers compared to other means of generating electricity for it to capture a growing market share to 2030".

In January 2010, the International Solar Energy Society stated that "... it appears that the pace of nuclear plant retirements will exceed the development of the few new plants now being contemplated, so that nuclear power may soon start on a downward trend. It will remain to be seen if it has any place in an affordable future world energy policy".

In March 2010, Steve Kidd from the World Nuclear Association said: "Proof of whether the mooted nuclear renaissance is merely 'industry hype' as some commentators suggest or reality will come over the next decade". In 2013 Kidd characterised the situation as a nuclear slowdown, requiring the industry to focus on better economics and improving public acceptance.

In August 2010, physicist Michael Dittmar stated that: "Nuclear fission's contribution to total electric energy has decreased from about 18 per cent a decade ago to about 14 per cent in 2008. On a worldwide scale, nuclear energy is thus only a small component of the global energy mix and its share, contrary to widespread belief, is not on the rise".

In March 2011, Alexander Glaser said: "It will take time to grasp the full impact of the unimaginable human tragedy unfolding after the earthquake and tsunami in Japan, but it is already clear that the proposition of a global nuclear renaissance ended on that day".

In 2011, Benjamin K. Sovacool said: "The nuclear waste issue, although often ignored in industry press releases and sponsored reports, is the proverbial elephant in the room stopping a nuclear renaissance".

 

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Enriched uranium

From Wikipedia, the free encyclopedia
 
Proportions of uranium-238 (blue) and uranium-235 (red) found naturally versus enriched grades

Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U with 99.2739–99.2752% natural abundance), uranium-235 (235U, 0.7198–0.7202%), and uranium-234 (234U, 0.0050–0.0059%). 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons.

Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons. The International Atomic Energy Agency attempts to monitor and control enriched uranium supplies and processes in its efforts to ensure nuclear power generation safety and curb nuclear weapons proliferation.

There are about 2,000 tonnes of highly enriched uranium in the world, produced mostly for nuclear power, nuclear weapons, naval propulsion, and smaller quantities for research reactors.

The 238U remaining after enrichment is known as depleted uranium (DU), and is considerably less radioactive than even natural uranium, though still very dense and extremely hazardous in granulated form – such granules are a natural by-product of the shearing action that makes it useful for armor-penetrating weapons. Despite being mildly radioactive, depleted uranium is also an effective radiation shielding material.

Grades

Uranium as it is taken directly from the Earth is not suitable as fuel for most nuclear reactors and requires additional processes to make it usable. Uranium is mined either underground or in an open pit depending on the depth at which it is found. After the uranium ore is mined, it must go through a milling process to extract the uranium from the ore.

This is accomplished by a combination of chemical processes with the end product being concentrated uranium oxide, which is known as "yellowcake", contains roughly 60% uranium whereas the ore typically contains less than 1% uranium and as little as 0.1% uranium.

After the milling process is complete, the uranium must next undergo a process of conversion, "to either uranium dioxide, which can be used as the fuel for those types of reactors that do not require enriched uranium, or into uranium hexafluoride, which can be enriched to produce fuel for the majority of types of reactors". Naturally-occurring uranium is made of a mixture of 235U and 238U. The 235U is fissile, meaning it is easily split with neutrons while the remainder is 238U, but in nature, more than 99% of the extracted ore is 238U. Most nuclear reactors require enriched uranium, which is uranium with higher concentrations of 235U ranging between 3.5% and 4.5% (although a few reactor designs using a graphite or heavy water moderator, such as the RBMK and CANDU, are capable of operating with natural uranium as fuel). There are two commercial enrichment processes: gaseous diffusion and gas centrifugation. Both enrichment processes involve the use of uranium hexafluoride and produce enriched uranium oxide.

A drum of yellowcake (a mixture of uranium precipitates)

Reprocessed uranium (RepU)

Reprocessed uranium (RepU) is a product of nuclear fuel cycles involving nuclear reprocessing of spent fuel. RepU recovered from light water reactor (LWR) spent fuel typically contains slightly more 235U than natural uranium, and therefore could be used to fuel reactors that customarily use natural uranium as fuel, such as CANDU reactors. It also contains the undesirable isotope uranium-236, which undergoes neutron capture, wasting neutrons (and requiring higher 235U enrichment) and creating neptunium-237, which would be one of the more mobile and troublesome radionuclides in deep geological repository disposal of nuclear waste.

Low enriched uranium (LEU)

Low enriched uranium (LEU) has a lower than 20% concentration of 235U; for instance, in commercial LWR, the most prevalent power reactors in the world, uranium is enriched to 3 to 5% 235U. High-assay LEU (HALEU) is enriched from 5–20%. Fresh LEU used in research reactors is usually enriched 12 to 19.75% 235U, the latter concentration is used to replace HEU fuels when converting to LEU.

Highly enriched uranium (HEU)

A billet of highly enriched uranium metal

Highly enriched uranium (HEU) has a 20% or higher concentration of 235U. The fissile uranium in nuclear weapon primaries usually contains 85% or more of 235U known as weapons-grade, though theoretically for an implosion design, a minimum of 20% could be sufficient (called weapon-usable) although it would require hundreds of kilograms of material and "would not be practical to design"; even lower enrichment is hypothetically possible, but as the enrichment percentage decreases the critical mass for unmoderated fast neutrons rapidly increases, with for example, an infinite mass of 5.4% 235U being required. For criticality experiments, enrichment of uranium to over 97% has been accomplished.

The very first uranium bomb, Little Boy, dropped by the United States on Hiroshima in 1945, used 64 kilograms of 80% enriched uranium. Wrapping the weapon's fissile core in a neutron reflector (which is standard on all nuclear explosives) can dramatically reduce the critical mass. Because the core was surrounded by a good neutron reflector, at explosion it comprised almost 2.5 critical masses. Neutron reflectors, compressing the fissile core via implosion, fusion boosting, and "tamping", which slows the expansion of the fissioning core with inertia, allow nuclear weapon designs that use less than what would be one bare-sphere critical mass at normal density. The presence of too much of the 238U isotope inhibits the runaway nuclear chain reaction that is responsible for the weapon's power. The critical mass for 85% highly enriched uranium is about 50 kilograms (110 lb), which at normal density would be a sphere about 17 centimetres (6.7 in) in diameter.

Later US nuclear weapons usually use plutonium-239 in the primary stage, but the jacket or tamper secondary stage, which is compressed by the primary nuclear explosion often uses HEU with enrichment between 40% and 80% along with the fusion fuel lithium deuteride. For the secondary of a large nuclear weapon, the higher critical mass of less-enriched uranium can be an advantage as it allows the core at explosion time to contain a larger amount of fuel. The 238U is not said to be fissile but still is fissionable by fast neutrons (>2 MeV) such as the ones produced during D-T fusion.

HEU is also used in fast neutron reactors, whose cores require about 20% or more of fissile material, as well as in naval reactors, where it often contains at least 50% 235U, but typically does not exceed 90%. The Fermi-1 commercial fast reactor prototype used HEU with 26.5% 235U. Significant quantities of HEU are used in the production of medical isotopes, for example molybdenum-99 for technetium-99m generators.

Enrichment methods

Isotope separation is difficult because two isotopes of the same element have nearly identical chemical properties, and can only be separated gradually using small mass differences. (235U is only 1.26% lighter than 238U). This problem is compounded because uranium is rarely separated in its atomic form, but instead as a compound (235UF6 is only 0.852% lighter than 238UF6). A cascade of identical stages produces successively higher concentrations of 235U. Each stage passes a slightly more concentrated product to the next stage and returns a slightly less concentrated residue to the previous stage.

There are currently two generic commercial methods employed internationally for enrichment: gaseous diffusion (referred to as first generation) and gas centrifuge (second generation), which consumes only 2% to 2.5% as much energy as gaseous diffusion (at least a "factor of 20" more efficient). Some work is being done that would use nuclear resonance; however there is no reliable evidence that any nuclear resonance processes have been scaled up to production.

Diffusion techniques

Gaseous diffusion

Gaseous diffusion uses semi-permeable membranes to separate enriched uranium

Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride (hex) through semi-permeable membranes. This produces a slight separation between the molecules containing 235U and 238U. Throughout the Cold War, gaseous diffusion played a major role as a uranium enrichment technique, and as of 2008 accounted for about 33% of enriched uranium production, but in 2011 was deemed an obsolete technology that is steadily being replaced by the later generations of technology as the diffusion plants reach their ends-of-life. In 2013, the Paducah facility in the US ceased operating, it was the last commercial 235U gaseous diffusion plant in the world.

Thermal diffusion

Thermal diffusion uses the transfer of heat across a thin liquid or gas to accomplish isotope separation. The process exploits the fact that the lighter 235U gas molecules will diffuse toward a hot surface, and the heavier 238U gas molecules will diffuse toward a cold surface. The S-50 plant at Oak Ridge, Tennessee was used during World War II to prepare feed material for the EMIS process. It was abandoned in favor of gaseous diffusion.

Centrifuge techniques

Gas centrifuge

A cascade of gas centrifuges at a U.S. enrichment plant

The gas centrifuge process uses a large number of rotating cylinders in series and parallel formations. Each cylinder's rotation creates a strong centripetal force so that the heavier gas molecules containing 238U move tangentially toward the outside of the cylinder and the lighter gas molecules rich in 235U collect closer to the center. It requires much less energy to achieve the same separation than the older gaseous diffusion process, which it has largely replaced and so is the current method of choice and is termed second generation. It has a separation factor per stage of 1.3 relative to gaseous diffusion of 1.005, which translates to about one-fiftieth of the energy requirements. Gas centrifuge techniques produce close to 100% of the world's enriched uranium.

Zippe centrifuge

Diagram of the principles of a Zippe-type gas centrifuge with U-238 represented in dark blue and U-235 represented in light blue

The Zippe centrifuge is an improvement on the standard gas centrifuge, the primary difference being the use of heat. The bottom of the rotating cylinder is heated, producing convection currents that move the 235U up the cylinder, where it can be collected by scoops. This improved centrifuge design is used commercially by Urenco to produce nuclear fuel and was used by Pakistan in their nuclear weapons program.

Laser techniques

Laser processes promise lower energy inputs, lower capital costs and lower tails assays, hence significant economic advantages. Several laser processes have been investigated or are under development. Separation of isotopes by laser excitation (SILEX) is well developed and is licensed for commercial operation as of 2012.

Atomic vapor laser isotope separation (AVLIS)

Atomic vapor laser isotope separation employs specially tuned lasers to separate isotopes of uranium using selective ionization of hyperfine transitions. The technique uses lasers tuned to frequencies that ionize 235U atoms and no others. The positively charged 235U ions are then attracted to a negatively charged plate and collected.

Molecular laser isotope separation (MLIS)

Molecular laser isotope separation uses an infrared laser directed at UF6, exciting molecules that contain a 235U atom. A second laser frees a fluorine atom, leaving uranium pentafluoride, which then precipitates out of the gas.

Separation of isotopes by laser excitation (SILEX)

Separation of isotopes by laser excitation is an Australian development that also uses UF6. After a protracted development process involving U.S. enrichment company USEC acquiring and then relinquishing commercialization rights to the technology, GE Hitachi Nuclear Energy (GEH) signed a commercialization agreement with Silex Systems in 2006. GEH has since built a demonstration test loop and announced plans to build an initial commercial facility. Details of the process are classified and restricted by intergovernmental agreements between United States, Australia, and the commercial entities. SILEX has been projected to be an order of magnitude more efficient than existing production techniques but again, the exact figure is classified. In August, 2011 Global Laser Enrichment, a subsidiary of GEH, applied to the U.S. Nuclear Regulatory Commission (NRC) for a permit to build a commercial plant. In September 2012, the NRC issued a license for GEH to build and operate a commercial SILEX enrichment plant, although the company had not yet decided whether the project would be profitable enough to begin construction, and despite concerns that the technology could contribute to nuclear proliferation.

Other techniques

Aerodynamic processes

Schematic diagram of an aerodynamic nozzle. Many thousands of these small foils would be combined in an enrichment unit.
 
The X-ray based LIGA manufacturing process was originally developed at the Forschungszentrum Karlsruhe, Germany, to produce nozzles for isotope enrichment.

Aerodynamic enrichment processes include the Becker jet nozzle techniques developed by E. W. Becker and associates using the LIGA process and the vortex tube separation process. These aerodynamic separation processes depend upon diffusion driven by pressure gradients, as does the gas centrifuge. They in general have the disadvantage of requiring complex systems of cascading of individual separating elements to minimize energy consumption. In effect, aerodynamic processes can be considered as non-rotating centrifuges. Enhancement of the centrifugal forces is achieved by dilution of UF6 with hydrogen or helium as a carrier gas achieving a much higher flow velocity for the gas than could be obtained using pure uranium hexafluoride. The Uranium Enrichment Corporation of South Africa (UCOR) developed and deployed the continuous Helikon vortex separation cascade for high production rate low enrichment and the substantially different semi-batch Pelsakon low production rate high enrichment cascade both using a particular vortex tube separator design, and both embodied in industrial plant. A demonstration plant was built in Brazil by NUCLEI, a consortium led by Industrias Nucleares do Brasil that used the separation nozzle process. However all methods have high energy consumption and substantial requirements for removal of waste heat; none are currently still in use.

Electromagnetic isotope separation

Schematic diagram of uranium isotope separation in a calutron shows how a strong magnetic field is used to redirect a stream of uranium ions to a target, resulting in a higher concentration of uranium-235 (represented here in dark blue) in the inner fringes of the stream.

In the electromagnetic isotope separation process (EMIS), metallic uranium is first vaporized, and then ionized to positively charged ions. The cations are then accelerated and subsequently deflected by magnetic fields onto their respective collection targets. A production-scale mass spectrometer named the Calutron was developed during World War II that provided some of the 235U used for the Little Boy nuclear bomb, which was dropped over Hiroshima in 1945. Properly the term 'Calutron' applies to a multistage device arranged in a large oval around a powerful electromagnet. Electromagnetic isotope separation has been largely abandoned in favour of more effective methods.

Chemical methods

One chemical process has been demonstrated to pilot plant stage but not used for production. The French CHEMEX process exploited a very slight difference in the two isotopes' propensity to change valency in oxidation/reduction, using immiscible aqueous and organic phases. An ion-exchange process was developed by the Asahi Chemical Company in Japan that applies similar chemistry but effects separation on a proprietary resin ion-exchange column.

Plasma separation

Plasma separation process (PSP) describes a technique that makes use of superconducting magnets and plasma physics. In this process, the principle of ion cyclotron resonance is used to selectively energize the 235U isotope in a plasma containing a mix of ions. The French developed their own version of PSP, which they called RCI. Funding for RCI was drastically reduced in 1986, and the program was suspended around 1990, although RCI is still used for stable isotope separation.

Separative work unit

"Separative work" – the amount of separation done by an enrichment process – is a function of the concentrations of the feedstock, the enriched output, and the depleted tailings; and is expressed in units that are so calculated as to be proportional to the total input (energy / machine operation time) and to the mass processed. Separative work is not energy. The same amount of separative work will require different amounts of energy depending on the efficiency of the separation technology. Separative work is measured in Separative work units SWU, kg SW, or kg UTA (from the German Urantrennarbeit – literally uranium separation work)

  • 1 SWU = 1 kg SW = 1 kg UTA
  • 1 kSWU = 1 tSW = 1 t UTA
  • 1 MSWU = 1 ktSW = 1 kt UTA

Cost issues

In addition to the separative work units provided by an enrichment facility, the other important parameter to be considered is the mass of natural uranium (NU) that is needed to yield a desired mass of enriched uranium. As with the number of SWUs, the amount of feed material required will also depend on the level of enrichment desired and upon the amount of 235U that ends up in the depleted uranium. However, unlike the number of SWUs required during enrichment, which increases with decreasing levels of 235U in the depleted stream, the amount of NU needed will decrease with decreasing levels of 235U that end up in the DU.

For example, in the enrichment of LEU for use in a light water reactor it is typical for the enriched stream to contain 3.6% 235U (as compared to 0.7% in NU) while the depleted stream contains 0.2% to 0.3% 235U. In order to produce one kilogram of this LEU it would require approximately 8 kilograms of NU and 4.5 SWU if the DU stream was allowed to have 0.3% 235U. On the other hand, if the depleted stream had only 0.2% 235U, then it would require just 6.7 kilograms of NU, but nearly 5.7 SWU of enrichment. Because the amount of NU required and the number of SWUs required during enrichment change in opposite directions, if NU is cheap and enrichment services are more expensive, then the operators will typically choose to allow more 235U to be left in the DU stream whereas if NU is more expensive and enrichment is less so, then they would choose the opposite.

Downblending

The opposite of enriching is downblending; surplus HEU can be downblended to LEU to make it suitable for use in commercial nuclear fuel.

The HEU feedstock can contain unwanted uranium isotopes: 234U is a minor isotope contained in natural uranium; during the enrichment process, its concentration increases but remains well below 1%. High concentrations of 236U are a byproduct from irradiation in a reactor and may be contained in the HEU, depending on its manufacturing history. HEU reprocessed from nuclear weapons material production reactors (with an 235U assay of approx. 50%) may contain 236U concentrations as high as 25%, resulting in concentrations of approximately 1.5% in the blended LEU product. 236U is a neutron poison; therefore the actual 235U concentration in the LEU product must be raised accordingly to compensate for the presence of 236U.

The blendstock can be NU, or DU, however depending on feedstock quality, SEU at typically 1.5 wt% 235U may used as a blendstock to dilute the unwanted byproducts that may be contained in the HEU feed. Concentrations of these isotopes in the LEU product in some cases could exceed ASTM specifications for nuclear fuel, if NU, or DU were used. So, the HEU downblending generally cannot contribute to the waste management problem posed by the existing large stockpiles of depleted uranium. At present, 95 percent of the world's stocks of depleted uranium remain in secure storage.[citation needed]

A major downblending undertaking called the Megatons to Megawatts Program converts ex-Soviet weapons-grade HEU to fuel for U.S. commercial power reactors. From 1995 through mid-2005, 250 tonnes of high-enriched uranium (enough for 10,000 warheads) was recycled into low-enriched-uranium. The goal is to recycle 500 tonnes by 2013. The decommissioning programme of Russian nuclear warheads accounted for about 13% of total world requirement for enriched uranium leading up to 2008.

The United States Enrichment Corporation has been involved in the disposition of a portion of the 174.3 tonnes of highly enriched uranium (HEU) that the U.S. government declared as surplus military material in 1996. Through the U.S. HEU Downblending Program, this HEU material, taken primarily from dismantled U.S. nuclear warheads, was recycled into low-enriched uranium (LEU) fuel, used by nuclear power plants to generate electricity.

Global enrichment facilities

The following countries are known to operate enrichment facilities: Argentina, Brazil, China, France, Germany, India, Iran, Japan, the Netherlands, North Korea, Pakistan, Russia, the United Kingdom, and the United States. Belgium, Iran, Italy, and Spain hold an investment interest in the French Eurodif enrichment plant, with Iran's holding entitling it to 10% of the enriched uranium output. Countries that had enrichment programs in the past include Libya and South Africa, although Libya's facility was never operational. Australia has developed a laser enrichment process known as SILEX, which it intends to pursue through financial investment in a U.S. commercial venture by General Electric. It has also been claimed that Israel has a uranium enrichment program housed at the Negev Nuclear Research Center site near Dimona.

Codename

During the Manhattan Project, weapons-grade highly enriched uranium was given the codename oralloy, a shortened version of Oak Ridge alloy, after the location of the plants where the uranium was enriched. The term oralloy is still occasionally used to refer to enriched uranium.
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