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Friday, June 4, 2021

MOX fuel

From Wikipedia, the free encyclopedia

Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material, usually consisting of plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium (LEU) fuel used in the light water reactors that predominate nuclear power generation.

For example, a mixture of 7% plutonium and 93% natural uranium reacts similarly, although not identically, to LEU fuel. MOX usually consists of two phases, UO2 and PuO2, and/or a single phase solid solution (U,Pu)O2. The content of PuO2 may vary from 1.5 wt.% to 25–30 wt.% depending on the type of nuclear reactor.

One attraction of MOX fuel is that it is a way of utilizing surplus weapons-grade plutonium, an alternative to storage of surplus plutonium, which would need to be secured against the risk of theft for use in nuclear weapons. On the other hand, some studies warned that normalising the global commercial use of MOX fuel and the associated expansion of nuclear reprocessing will increase, rather than reduce, the risk of nuclear proliferation, by encouraging increased separation of plutonium from spent fuel in the civil nuclear fuel cycle.

Overview

In every uranium-based nuclear reactor core there is both fission of uranium isotopes such as uranium-235, and the formation of new, heavier isotopes due to neutron capture, primarily by uranium-238. Most of the fuel mass in a reactor is uranium-238. By neutron capture and two successive beta decays, uranium-238 becomes plutonium-239, which, by successive neutron capture, becomes plutonium-240, plutonium-241, plutonium-242, and (after further beta decays) other transuranic or actinide nuclides. Plutonium-239 and plutonium-241 are fissile, like uranium-235. Small quantities of uranium-236, neptunium-237 and plutonium-238 are formed similarly from uranium-235.

Normally, with the fuel being changed every three years or so, most of the plutonium-239 is "burned" in the reactor. It behaves like uranium-235, with a slightly higher cross section for fission, and its fission releases a similar amount of energy. Typically, about one percent of the spent fuel discharged from a reactor is plutonium, and some two-thirds of the plutonium is plutonium-239. Worldwide, almost 100 tonnes of plutonium in spent fuel arises each year. A single recycling of plutonium increases the energy derived from the original uranium by some 12%, and if the uranium-235 is also recycled by re-enrichment, this becomes about 20%. With additional recycling the percentage of fissile (usually meaning odd-neutron number) nuclides in the mix decreases and even-neutron number, neutron-absorbing nuclides increase, requiring the total plutonium and/or enriched uranium percentage to be increased. Today in thermal reactors plutonium is only recycled once as MOX fuel; spent MOX fuel, with a high proportion of minor actinides and even plutonium isotopes, is stored as waste.

Existing nuclear reactors must be re-licensed before MOX fuel can be introduced because using it changes the operating characteristics of a reactor, and the plant must be designed or adapted slightly to take it; for example, more control rods are needed. Often only a third to half of the fuel load is switched to MOX, but for more than 50% MOX loading, significant changes are necessary and a reactor needs to be designed accordingly. The System 80 reactor design, notably deployed at the U.S. Palo Verde Nuclear Generating Station near Phoenix, Arizona, was designed for 100% MOX core compatibility, but so far has always operated on fresh low enriched uranium. In theory, the three Palo Verde reactors could use the MOX arising from seven conventionally fueled reactors each year and would no longer require fresh uranium fuel.

According to Atomic Energy of Canada Limited (AECL), CANDU reactors could use 100% MOX cores without physical modification. AECL reported to the United States National Academy of Sciences committee on plutonium disposition that it has extensive experience in testing the use of MOX fuel containing from 0.5 to 3% plutonium.

The content of un-burnt plutonium in spent MOX fuel from thermal reactors is significant – greater than 50% of the initial plutonium loading. However, during the burning of MOX the ratio of fissile (odd numbered) isotopes to non-fissile (even) drops from around 65% to 20%, depending on burn up. This makes any attempt to recover the fissile isotopes difficult and any bulk Pu recovered would require such a high fraction of Pu in any second generation MOX that it would be impractical. This means that such a spent fuel would be difficult to reprocess for further reuse (burning) of plutonium. Regular reprocessing of biphasic spent MOX is difficult because of the low solubility of PuO2 in nitric acid. As of 2015, the only commercial demonstration of twice recycled, high burnup fuel occurred in the Phénix fast reactor.

Current applications

A used MOX, which has 63 GW days (thermal) of burnup and has been examined with a scanning electron microscope using electron microprobe attachment. The lighter the pixel in the right hand side the higher the plutonium content of the material at that spot

Reprocessing of commercial nuclear fuel to make MOX is done in the United Kingdom and France, and to a lesser extent in Russia, India and Japan. China plans to develop fast breeder reactors and reprocessing. Reprocessing of spent commercial-reactor nuclear fuel is not permitted in the United States due to nonproliferation considerations. All of these nations have long had nuclear weapons from military-focused research reactor fuels except Japan.

The United States was building a MOX plant at the Savannah River Site in South Carolina. Although the Tennessee Valley Authority (TVA) and Duke Energy expressed interest in using MOX reactor fuel from the conversion of weapons-grade plutonium, TVA (currently the most likely customer) said in April 2011 that it would delay a decision until it could see how MOX fuel performed in the nuclear accident at Fukushima Daiichi. In May 2018, the Department of Energy reported that the plant would require another $48 billion to complete, on top of the $7.6 billion already spent. Construction was cancelled.

Thermal reactors

About 30 thermal reactors in Europe (Belgium, the Netherlands, Switzerland, Germany and France) are using MOX and an additional 20 have been licensed to do so. Most reactors use it as about one third of their core, but some will accept up to 50% MOX assemblies. In France, EDF aims to have all its 900 MWe series of reactors running with at least one-third MOX. Japan aimed to have one third of its reactors using MOX by 2010, and has approved construction of a new reactor with a complete fuel loading of MOX. Of the total nuclear fuel used today, MOX provides 2%.

Licensing and safety issues of using MOX fuel include:

  • As plutonium isotopes absorb more neutrons than uranium fuels, reactor control systems may need modification.
  • MOX fuel tends to run hotter because of lower thermal conductivity, which may be an issue in some reactor designs.
  • Fission gas release in MOX fuel assemblies may limit the maximum burn-up time of MOX fuel.

About 30% of the plutonium originally loaded into MOX fuel is consumed by use in a thermal reactor. In theory, if one third of the core fuel load is MOX and two-thirds uranium fuel, there is zero net gain of plutonium in the spent fuel, and the cycle could be repeated; however, there remains multiple difficulties in reprocessing spent MOX fuel. As of 2010, plutonium is only recycled once in thermal reactors, and spent MOX fuel is separated from the rest of the spent fuel to be stored as waste.

All plutonium isotopes are either fissile or fertile, although plutonium-242 needs to absorb 3 neutrons before becoming fissile curium-245; in thermal reactors isotopic degradation limits the plutonium recycle potential. About 1% of spent nuclear fuel from current LWRs is plutonium, with approximate isotopic composition 52% 239
94
Pu
, 24% 240
94
Pu
, 15% 241
94
Pu
, 6% 242
94
Pu
and 2% 238
94
Pu
when the fuel is first removed from the reactor.

Fast reactors

Because the fission-to-capture ratio of neutron cross-section with high energy or fast neutrons changes to favour fission for almost all of the actinides, including 238
92
U
, fast reactors can use all of them for fuel. All actinides, including TRU or transuranium actinides can undergo neutron induced fission with unmoderated or fast neutrons. A fast reactor is more efficient for using plutonium and higher actinides as fuel. Depending on how the reactor is fueled it can either be used as a plutonium breeder or burner.

These fast reactors are better suited for the transmutation of other actinides than thermal reactors. Because thermal reactors use slow or moderated neutrons, the actinides that are not fissionable with thermal neutrons tend to absorb the neutrons instead of fissioning. This leads to buildup of heavier actinides and lowers the number of thermal neutrons available to continue the chain reaction.

Fabrication

The first step is separating the plutonium from the remaining uranium (about 96% of the spent fuel) and the fission products with other wastes (together about 3%). This is undertaken at a nuclear reprocessing plant.

Dry mixing

MOX fuel can be made by grinding together uranium oxide (UO2) and plutonium oxide (PuO2) before the mixed oxide is pressed into pellets, but this process has the disadvantage of forming much radioactive dust. MOX fuel, consisting of 7% plutonium mixed with depleted uranium, is equivalent to uranium oxide fuel enriched to about 4.5% 235
92
U
, assuming that the plutonium has about 60–65% 239
94
Pu
. If weapons-grade plutonium were used (>90% 239
94
Pu
), only about 5% plutonium would be needed in the mix.

Coprecipitation

A mixture of uranyl nitrate and plutonium nitrate in nitric acid is converted by treatment with a base such as ammonia to form a mixture of ammonium diuranate and plutonium hydroxide. After heating in a mixture of 5% hydrogen and 95% argon will form a mixture of uranium dioxide and plutonium dioxide. Using a base, the resulting powder can be run through a press and converted into green colored pellets. The green pellet can then be sintered into mixed uranium and plutonium oxide pellet. While this second type of fuel is more homogenous on the microscopic scale (scanning electron microscope) it is possible to see plutonium rich areas and plutonium poor areas. It can be helpful to think of the solid as being like a salami (more than one solid material present in the pellet).

Americium content

Plutonium from reprocessed fuel is usually fabricated into MOX within less than five years of its production to avoid problems resulting from impurities produced by the decay of short-lived isotopes of plutonium. In particular, plutonium-241 decays to americium-241 with a 14-year half-life. Because americium-241 is a gamma ray emitter, its presence is a potential occupational health hazard. It is possible, however, to remove the americium from the plutonium by a chemical separation process. Even under the worst conditions, the americium/plutonium mixture is less radioactive than a spent-fuel dissolution liquor, so it should be relatively straightforward to recover the plutonium by PUREX or another aqueous reprocessing method.

Curium content

It is possible that both americium and curium could be added to a U/Pu MOX fuel before it is loaded into a fast reactor. This is one means of transmutation. Work with curium is much harder than americium because curium is a neutron emitter, the MOX production line would need to be shielded with both lead and water to protect the workers.

Also, the neutron irradiation of curium generates the higher actinides, such as californium, which increase the neutron dose associated with the used nuclear fuel; this has the potential to pollute the fuel cycle with strong neutron emitters. As a result, it is likely that curium will be excluded from most MOX fuels.

Thorium MOX

MOX fuel containing thorium and plutonium oxides is also being tested. According to a Norwegian study, "the coolant void reactivity of the thorium-plutonium fuel is negative for plutonium contents up to 21%, whereas the transition lies at 16% for MOX fuel." The authors concluded, "Thorium-plutonium fuel seems to offer some advantages over MOX fuel with regards to control rod and boron worths, CVR and plutonium consumption."

Economics of nuclear power plants

From Wikipedia, the free encyclopedia
 
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. On 29 June 2019, it was announced that the start-up was once again being pushed back, making it unlikely it could be started before the end of 2022. In July 2020, the French Court of Audit finalised an eighteen-month in-depth analysis of the project, concluding that the total estimated cost reaches up to €19.1 billion which is more than 5 times the original cost estimate. Similarly, the cost of the EPR being built at Olkiluoto, Finland, has escalated dramatically from €3 billion to over €12 billion , and the project is well behind schedule. Originally to commence operation in 2009 and that is now unlikely to be before 2022. The initial low cost forecasts for these megaprojects exhibited "optimism bias".

New nuclear power plants typically have high capital expenditure for building the plant. Fuel, operational, and maintenance costs are relatively small components of the total cost. The long service life and high capacity factor of nuclear power plants allow sufficient funds for ultimate plant decommissioning and waste storage and management to be accumulated, with little impact on the price per unit of electricity generated. Other groups disagree with these statements. Additionally, measures to mitigate climate change such as a carbon tax or carbon emissions trading, would favor the economics of nuclear power over fossil fuel power. Other groups argue that nuclear power is not the answer to climate change.

Nuclear power construction costs have varied significantly across the world and in time. Large and rapid increases in cost occurred during the 1970s, especially in the United States. There were no construction starts of nuclear power reactors between 1979 and 2012 in the United States, and since then more new reactor projects have gone into bankruptcy than have been completed. Recent cost trends in countries such as Japan and Korea have been very different, including periods of stability and decline in costs.

In more economically developed countries, a slowdown in electricity demand growth in recent years has made large-scale power infrastructure investments difficult. Very large upfront costs and long project cycles carry large risks, including political decision making and intervention such as regulatory ratcheting. In Eastern Europe, a number of long-established projects are struggling to find financing, notably Belene in Bulgaria and the additional reactors at Cernavoda in Romania, and some potential backers have pulled out. Where cheap gas is available and its future supply relatively secure, this also poses a major problem for clean energy projects. Former Exelon CEO John Rowe said in 2012 that new nuclear plants in the United States "don't make any sense right now" and would not be economic as long as gas prices remain low.

Current bids for new nuclear power plants in China were estimated at between $2800/kW and $3500/kW, as China planned to accelerate its new build program after a pause following the Fukushima disaster. However, more recent reports indicated that China will fall short of its targets. While nuclear power in China has been cheaper than solar and wind power, these are getting cheaper while nuclear power costs are growing. Moreover, third generation plants are expected to be considerably more expensive than earlier plants. Therefore, comparison with other power generation methods is strongly dependent on assumptions about construction timescales and capital financing for nuclear plants. Analysis of the economics of nuclear power must take into account who bears the risks of future uncertainties. To date all operating nuclear power plants were developed by state-owned or regulated utility monopolies where many of the risks associated with political change and regulatory ratcheting were borne by consumers rather than suppliers. Many countries have now liberalized the electricity market where these risks, and the risk of cheap competition from subsidised energy sources emerging before capital costs are recovered, are borne by plant suppliers and operators rather than consumers, which leads to a significantly different evaluation of the risk of investing in new nuclear power plants.

Two of the four EPRs under construction (the Olkiluoto Nuclear Power Plant in Finland and Flamanville in France), which are the latest new builds in Europe, are significantly behind schedule and substantially over cost. Following the 2011 Fukushima Daiichi nuclear disaster, costs are likely to go up for some types of currently operating and new nuclear power plants, due to new requirements for on-site spent fuel management and elevated design basis threats.

Overview

Olkiluoto 3 under construction in 2009. It is the first EPR design, but problems with workmanship and supervision have created costly delays which led to an inquiry by the Finnish nuclear regulator STUK. In December 2012, Areva estimated that the full cost of building the reactor will be about €8.5 billion, or almost three times the original delivery price of €3 billion.

Although the price of new plants in China is lower than in the Western world John Quiggin, an economics professor, maintains that the main problem with the nuclear option is that it is not economically viable. Professor of science and technology Ian Lowe has also challenged the economics of nuclear power. However, nuclear supporters continue to point to the historical success of nuclear power across the world, and they call for new reactors in their own countries, including proposed new but largely uncommercialised designs, as a source of new power. Nuclear supporters point out that the IPCC climate panel endorses nuclear technology as a low carbon, mature energy source which should be nearly quadrupled to help address soaring greenhouse gas emissions.

Some independent reviews keep repeating that nuclear power plants are necessarily very expensive, and anti-nuclear groups frequently produce reports that say the costs of nuclear energy are prohibitively high.

In 2012 in Ontario, Canada, costs for nuclear generation stood at 5.9¢/kWh while hydroelectricity, at 4.3¢/kWh, cost 1.6¢ less than nuclear. By September 2015, the cost of solar in the United States dropped below nuclear generation costs, averaging 5¢/kWh. Solar costs continued to fall, and by February 2016, the City of Palo Alto, California, approved a power-purchase agreement (PPA) to purchase solar electricity for under 3.68¢/kWh, lower than even hydroelectricity. Utility-scale solar electricity generation newly contracted by Palo Alto in 2016 costs 2.22¢/kWh less than electricity from the already-completed Canadian nuclear plants, and the costs of solar energy generation continue to drop. However, solar power has very low capacity factors compared to nuclear, and solar power can only achieve so much market penetration before (expensive) energy storage and transmission become necessary.

Countries including Russia, India, and China, have continued to pursue new builds. Globally, around 50 nuclear power plants were under construction in 20 countries as of April 2020, according to the IAEA. China has 10 reactors under construction. According to the World Nuclear Association, the global trend is for new nuclear power stations coming online to be balanced by the number of old plants being retired.

In the United States, nuclear power faces competition from the low natural gas prices in North America. Former Exelon CEO John Rowe said in 2012 that new nuclear plants in the United States "don’t make any sense right now" and won't be economic as long as the natural gas glut persists. In 2016, Governor of New York Andrew Cuomo directed the New York Public Service Commission to consider ratepayer-financed subsidies similar to those for renewable sources to keep nuclear power stations profitable in the competition against natural gas.

A 2019 study by the economic think tank DIW found that nuclear power has not been profitable anywhere in the World. The study of the economics of nuclear power has found it has never been financially viable, that most plants have been built while heavily subsidised by governments, often motivated by military purposes, and that nuclear power is not a good approach to tackling climate change. It found, after reviewing trends in nuclear power plant construction since 1951, that the average 1,000MW nuclear power plant would incur an average economic loss of 4.8 billion euros ($7.7 billion AUD). This has been refuted by another study.

Capital costs

"The usual rule of thumb for nuclear power is that about two thirds of the generation cost is accounted for by fixed costs, the main ones being the cost of paying interest on the loans and repaying the capital..."

Capital cost, the building and financing of nuclear power plants, represents a large percentage of the cost of nuclear electricity. In 2014, the US Energy Information Administration estimated that for new nuclear plants going online in 2019, capital costs will make up 74% of the levelized cost of electricity; higher than the capital percentages for fossil-fuel power plants (63% for coal, 22% for natural gas), and lower than the capital percentages for some other nonfossil-fuel sources (80% for wind, 88% for solar PV).

Areva, the French nuclear plant operator, offers that 70% of the cost of a kWh of nuclear electricity is accounted for by the fixed costs from the construction process. Some analysts argue (for example Steve Thomas, Professor of Energy Studies at the University of Greenwich in the UK, quoted in the book The Doomsday Machine by Martin Cohen and Andrew McKillop) that what is often not appreciated in debates about the economics of nuclear power is that the cost of equity, that is companies using their own money to pay for new plants, is generally higher than the cost of debt. Another advantage of borrowing may be that "once large loans have been arranged at low interest rates – perhaps with government support – the money can then be lent out at higher rates of return".

"One of the big problems with nuclear power is the enormous upfront cost. These reactors are extremely expensive to build. While the returns may be very great, they're also very slow. It can sometimes take decades to recoup initial costs. Since many investors have a short attention span, they don't like to wait that long for their investment to pay off."

Because of the large capital costs for the initial nuclear power plants built as part of a sustained build program, and the relatively long construction period before revenue is returned, servicing the capital costs of first few nuclear power plants can be the most important factor determining the economic competitiveness of nuclear energy. The investment can contribute about 70% to 80% of the costs of electricity. Timothy Stone, businessman and nuclear expert, stated in 2017 "It has long been recognised that the only two numbers which matter in [new] nuclear power are the capital cost and the cost of capital." The discount rate chosen to cost a nuclear power plant's capital over its lifetime is arguably the most sensitive parameter to overall costs. Because of the long life of new nuclear power plants, most of the value of a new nuclear power plant is created for the benefit of future generations.

The recent liberalization of the electricity market in many countries has made the economics of nuclear power generation less attractive, and no new nuclear power plants have been built in a liberalized electricity market. Previously a monopolistic provider could guarantee output requirements decades into the future. Private generating companies now have to accept shorter output contracts and the risks of future lower-cost competition, so they desire a shorter return on investment period. This favours generation plant types with lower capital costs or high subsidies, even if associated fuel costs are higher. A further difficulty is that due to the large sunk costs but unpredictable future income from the liberalized electricity market, private capital is unlikely to be available on favourable terms, which is particularly significant for nuclear as it is capital-intensive. Industry consensus is that a 5% discount rate is appropriate for plants operating in a regulated utility environment where revenues are guaranteed by captive markets, and 10% discount rate is appropriate for a competitive deregulated or merchant plant environment; however the independent MIT study (2003) which used a more sophisticated finance model distinguishing equity and debt capital had a higher 11.5% average discount rate.

As states are declining to finance nuclear power plants, the sector is now much more reliant on the commercial banking sector. According to research done by Dutch banking research group Profundo, commissioned by BankTrack, in 2008 private banks invested almost €176 billion in the nuclear sector. Champions were BNP Paribas, with more than €13,5 billion in nuclear investments and Citigroup and Barclays on par with both over €11,4 billion in investments. Profundo added up investments in eighty companies in over 800 financial relationships with 124 banks in the following sectors: construction, electricity, mining, the nuclear fuel cycle and "other".

A 2016 study argued that while costs did increase in the past for reactors built in the past, this does not necessarily mean there is an inherent trend of cost escalation with nuclear power, as prior studies tended to examine a relatively small share of reactors built and that a full analysis shows that cost trends for reactors varied substantially by country and era.

Cost overruns

Construction delays can add significantly to the cost of a plant. Because a power plant does not earn income and currencies can inflate during construction, longer construction times translate directly into higher finance charges. Modern nuclear power plants are planned for construction in five years or less (42 months for CANDU ACR-1000, 60 months from order to operation for an AP1000, 48 months from first concrete to operation for an EPR and 45 months for an ESBWR) as opposed to over a decade for some previous plants. However, despite Japanese success with ABWRs, two of the four EPRs under construction (in Finland and France) are significantly behind schedule.

In the United States many new regulations were put in place in the years before and again immediately after the Three Mile Island accident's partial meltdown, resulting in plant startup delays of many years. The NRC has new regulations in place now, and the next plants will have NRC Final Design Approval before the customer buys them, and a Combined Construction and Operating License will be issued before construction starts, guaranteeing that if the plant is built as designed then it will be allowed to operate—thus avoiding lengthy hearings after completion.

In Japan and France, construction costs and delays are significantly diminished because of streamlined government licensing and certification procedures. In France, one model of reactor was type-certified, using a safety engineering process similar to the process used to certify aircraft models for safety. That is, rather than licensing individual reactors, the regulatory agency certified a particular design and its construction process to produce safe reactors. U.S. law permits type-licensing of reactors, a process which is being used on the AP1000 and the ESBWR.

In Canada, cost overruns for the Darlington Nuclear Generating Station, largely due to delays and policy changes, are often cited by opponents of new reactors. Construction started in 1981 at an estimated cost of $7.4 Billion 1993-adjusted CAD, and finished in 1993 at a cost of $14.5 billion. 70% of the price increase was due to interest charges incurred due to delays imposed to postpone units 3 and 4, 46% inflation over a 4-year period and other changes in financial policy. No new nuclear reactor has since been built in Canada, although a few have been and are undergoing refurbishment and environment assessment is complete for 4 new generation stations at Darlington with the Ontario government committed in keeping a nuclear base load of 50% or around 10GW.

In the United Kingdom and the United States cost overruns on nuclear plants contributed to the bankruptcies of several utility companies. In the United States these losses helped usher in energy deregulation in the mid-1990s that saw rising electricity rates and power blackouts in California. When the UK began privatizing utilities, its nuclear reactors "were so unprofitable they could not be sold." Eventually in 1996, the government gave them away. But the company that took them over, British Energy, had to be bailed out in 2004 to the extent of 3.4 billion pounds.

Operating costs

In general, coal and nuclear plants have the same types of operating costs (operations and maintenance plus fuel costs). However, nuclear has lower fuel costs but higher operating and maintenance costs.

Fuel costs

Nuclear plants require fissile fuel. Generally, the fuel used is uranium, although other materials may be used. In 2005, prices on the world market for uranium averaged US$20/lb (US$44.09/kg). On 2007-04-19, prices reached US$113/lb (US$249.12/kg). On 2008-07-02, the price had dropped to $59/lb.

Fuel costs account for about 28% of a nuclear plant's operating expenses. As of 2013, half the cost of reactor fuel was taken up by enrichment and fabrication, so that the cost of the uranium concentrate raw material was 14 percent of operating costs. Doubling the price of uranium would add about 10% to the cost of electricity produced in existing nuclear plants, and about half that much to the cost of electricity in future power plants. The cost of raw uranium contributes about $0.0015/kWh to the cost of nuclear electricity, while in breeder reactors the uranium cost falls to $0.000015/kWh.

As of 2008, mining activity was growing rapidly, especially from smaller companies, but putting a uranium deposit into production takes 10 years or more. The world's present measured resources of uranium, economically recoverable at a price of US$130/kg according to the industry groups Organisation for Economic Co-operation and Development (OECD), Nuclear Energy Agency (NEA) and International Atomic Energy Agency (IAEA), are enough to last for "at least a century" at current consumption rates.

According to the World Nuclear Association, "the world's present measured resources of uranium (5.7 Mt) in the cost category less than three times present spot prices and used only in conventional reactors, are enough to last for about 90 years. This represents a higher level of assured resources than is normal for most minerals. Further exploration and higher prices will certainly, on the basis of present geological knowledge, yield further resources as present ones are used up." The amount of uranium present in all currently known conventional reserves alone (excluding the huge quantities of currently-uneconomical uranium present in "unconventional" reserves such as phosphate/phosphorite deposits, seawater, and other sources) is enough to last over 200 years at current consumption rates. Fuel efficiency in conventional reactors has increased over time. Additionally, since 2000, 12–15% of world uranium requirements have been met by the dilution of highly enriched weapons-grade uranium from the decommissioning of nuclear weapons and related military stockpiles with depleted uranium, natural uranium, or partially-enriched uranium sources to produce low-enriched uranium for use in commercial power reactors. Similar efforts have been utilizing weapons-grade plutonium to produce mixed oxide (MOX) fuel, which is also produced from reprocessing used fuel. Other components of used fuel are currently less commonly utilized, but have a substantial capacity for reuse, especially so in next-generation fast neutron reactors. Over 35 European reactors are licensed to use MOX fuel, as well as Russian and American nuclear plants. Reprocessing of used fuel increases utilization by approximately 30%, while the widespread use of fast breeder reactors would allow for an increase of "50-fold or more" in utilization.

Waste disposal costs

All nuclear plants produce radioactive waste. To pay for the cost of storing, transporting and disposing these wastes in a permanent location, in the United States a surcharge of a tenth of a cent per kilowatt-hour is added to electricity bills. Roughly one percent of electrical utility bills in provinces using nuclear power are diverted to fund nuclear waste disposal in Canada.

In 2009, the Obama administration announced that the Yucca Mountain nuclear waste repository would no longer be considered the answer for U.S. civilian nuclear waste. Currently, there is no plan for disposing of the waste and plants will be required to keep the waste on the plant premises indefinitely.

The disposal of low level waste reportedly costs around £2,000/m³ in the UK. High level waste costs somewhere between £67,000/m³ and £201,000/m³. General division is 80%/20% of low level/high level waste, and one reactor produces roughly 12 m³ of high level waste annually.

In Canada, the NWMO was created in 2002 to oversee long term disposal of nuclear waste, and in 2007 adopted the Adapted Phased Management procedure. Long term management is subject to change based on technology and public opinion, but currently largely follows the recommendations for a centralized repository as first extensively outlined by AECL in 1988. It was determined after extensive review that following these recommendations would safely isolate the waste from the biosphere. The location has not yet been determined, and the project is expected to cost between $9 and $13 billion CAD for construction and operation for 60–90 years, employing roughly a thousand people for the duration. Funding is available and has been collected since 1978 under the Canadian Nuclear Fuel Waste Management Program. Very long term monitoring requires less staff since high-level waste is less toxic than naturally occurring uranium ore deposits within a few centuries.

The primary argument for pursuing IFR-style technology today is that it provides the best solution to the existing nuclear waste problem because fast reactors can be fueled from the waste products of existing reactors as well as from the plutonium used in weapons, as is the case of the discontinued EBR-II in Arco, Idaho, and in the operating, as of 2014, BN-800 reactor. Depleted uranium (DU) waste can also be used as fuel in fast reactors. Waste produced by a fast-neutron reactor and a pyroelectric refiner would consist only of fission products, which are produced at a rate of about one tonne per GWe-year. This is 5% as much as present reactors produce, and needs special custody for only 300 years instead of 300,000. Only 9.2% of fission products (strontium and caesium) contribute 99% of radiotoxicity; at some additional cost, these could be separated, reducing the disposal problem by a further factor of ten.

Decommissioning

At the end of a nuclear plant's lifetime, the plant must be decommissioned. This entails either dismantling, safe storage or entombment. In the United States, the Nuclear Regulatory Commission (NRC) requires plants to finish the process within 60 years of closing. Since it may cost $500 million or more to shut down and decommission a plant, the NRC requires plant owners to set aside money when the plant is still operating to pay for the future shutdown costs.

Decommissioning a reactor that has undergone a meltdown is inevitably more difficult and expensive. Three Mile Island was decommissioned 14 years after its incident for $837 million. The cost of the Fukushima disaster cleanup is not yet known, but has been estimated to cost around $100 billion. Chernobyl is not yet decommissioned, different estimates put the end date between 2013 and 2020.

Proliferation and terrorism

A 2011 report for the Union of Concerned Scientists stated that "the costs of preventing nuclear proliferation and terrorism should be recognized as negative externalities of civilian nuclear power, thoroughly evaluated, and integrated into economic assessments—just as global warming emissions are increasingly identified as a cost in the economics of coal-fired electricity".

"Construction of the ELWR was completed in 2013 and is optimized for civilian electricity production, but it has "dual-use" potential and can be modified to produce material for nuclear weapons."

Safety, security and accidents

2000 candles in memory of the Chernobyl disaster in 1986, at a commemoration 25 years after the nuclear accident, as well as for the Fukushima nuclear disaster of 2011.

Nuclear safety and security is a chief goal of the nuclear industry. Great care is taken so that accidents are avoided, and if unpreventable, have limited consequences. Accidents could stem from system failures related to faulty construction or pressure vessel embrittlement due to prolonged radiation exposure. As with any aging technology, risks of failure increase over time, and since many currently operating nuclear reactors were built in the mid 20th century, care must be taken to ensure proper operation. Many more recent reactor designs have been proposed, most of which include passive safety systems. These design considerations serve to significantly mitigate or totally prevent major accidents from occurring, even in the event of a system failure. Still, reactors must be designed, built, and operated properly to minimize accident risks. The Fukushima disaster represents one instance where these systems were not comprehensive enough, where the tsunami following the Tōhoku earthquake disabled the backup generators that were stabilizing the reactor. According to UBS AG, the Fukushima I nuclear accidents have cast doubt on whether even an advanced economy like Japan can master nuclear safety. Catastrophic scenarios involving terrorist attacks are also conceivable.

An interdisciplinary team from MIT estimated that given the expected growth of nuclear power from 2005 to 2055, at least four core damage incidents would be expected in that period (assuming only current designs were used – the number of incidents expected in that same time period with the use of advanced designs is only one). To date, there have been five core damage incidents in the world since 1970 (one at Three Mile Island in 1979; one at Chernobyl in 1986; and three at Fukushima-Daiichi in 2011), corresponding to the beginning of the operation of generation II reactors.

According to the Paul Scherrer Institute, the Chernobyl incident is the only incident ever to have caused any fatalities. The report that UNSCEAR presented to the UN General Assembly in 2011 states that 29 plant workers and emergency responders died from effects of radiation exposure, two died from causes related to the incident but unrelated to radiation, and one died from coronary thrombosis. It attributed fifteen cases of fatal thyroid cancer to the incident. It said there is no evidence the incident caused an ongoing increase in incidence of solid tumors or blood cancers in Eastern Europe.

In terms of nuclear accidents, the Union of Concerned Scientists have claimed that "reactor owners ... have never been economically responsible for the full costs and risks of their operations. Instead, the public faces the prospect of severe losses in the event of any number of potential adverse scenarios, while private investors reap the rewards if nuclear plants are economically successful. For all practical purposes, nuclear power's economic gains are privatized, while its risks are socialized".

However, the problem of insurance costs for worst-case scenarios is not unique to nuclear power: hydroelectric power plants are similarly not fully insured against a catastrophic event such as the Banqiao Dam disaster, where 11 million people lost their homes and from 30,000 to 200,000 people died, or large dam failures in general. Private insurers base dam insurance premiums on worst-case scenarios, so insurance for major disasters in this sector is likewise provided by the state. In the US, insurance coverage for nuclear reactors is provided by the combination of operator-purchased private insurance and the primarily operator-funded Price Anderson Act.

Any effort to construct a new nuclear facility around the world, whether an existing design or an experimental future design, must deal with NIMBY or NIABY objections. Because of the high profiles of the Three Mile Island accident and Chernobyl disaster, relatively few municipalities welcome a new nuclear reactor, processing plant, transportation route, or deep geological repository within their borders, and some have issued local ordinances prohibiting the locating of such facilities there.

Nancy Folbre, an economics professor at the University of Massachusetts, has questioned the economic viability of nuclear power following the 2011 Japanese nuclear accidents:

The proven dangers of nuclear power amplify the economic risks of expanding reliance on it. Indeed, the stronger regulation and improved safety features for nuclear reactors called for in the wake of the Japanese disaster will almost certainly require costly provisions that may price it out of the market.

The cascade of problems at Fukushima, from one reactor to another, and from reactors to fuel storage pools, will affect the design, layout and ultimately the cost of future nuclear plants.

In 1986, Pete Planchon conducted a demonstration of the inherent safety of the Integral Fast Reactor. Safety interlocks were turned off. Coolant circulation was turned off. Core temperature rose from the usual 1000 degrees Fahrenheit to 1430 degrees within 20 seconds. The boiling temperature of the sodium coolant is 1621 degrees. Within seven minutes the reactor had shut itself down without action from the operators, without valves, pumps, computers, auxiliary power, or any moving parts. The temperature was below the operating temperature. The reactor was not damaged. The operators were not injured. There was no release of radioactive material. The reactor was restarted with coolant circulation but the steam generator disconnected. The same scenario recurred. Three weeks later, the operators at Chernobyl repeated the latter experiment, ironically in a rush to complete a safety test, using a very different reactor, with tragic consequences. Safety of the Integral Fast Reactor depends on the composition and geometry of the core, not efforts by operators or computer algorithms.

Insurance

Insurance available to the operators of nuclear power plants varies by nation. The worst case nuclear accident costs are so large that it would be difficult for the private insurance industry to carry the size of the risk, and the premium cost of full insurance would make nuclear energy uneconomic.

Nuclear power has largely worked under an insurance framework that limits or structures accident liabilities in accordance with the Paris convention on nuclear third-party liability, the Brussels supplementary convention, the Vienna convention on civil liability for nuclear damage, and in the United States the Price-Anderson Act. It is often argued that this potential shortfall in liability represents an external cost not included in the cost of nuclear electricity.

However, the problem of insurance costs for worst-case scenarios is not unique to nuclear power: hydroelectric power plants are similarly not fully insured against a catastrophic event such as the Banqiao Dam disaster, where 11 million people lost their homes and from 30,000 to 200,000 people died, or large dam failures in general. Private insurers base dam insurance premiums on worst-case scenarios, so insurance for major disasters in this sector is likewise provided by the state.

In Canada, the Canadian Nuclear Liability Act requires nuclear power plant operators to obtain $650 million (CAD) of liability insurance coverage per installation (regardless of the number of individual reactors present) starting in 2017 (up from the prior $75 million requirement established in 1976), increasing to $750 million in 2018, to $850 million in 2019, and finally to $1 billion in 2020. Claims beyond the insured amount would be assessed by a government appointed but independent tribunal, and paid by the federal government.

In the UK, the Nuclear Installations Act 1965 governs liability for nuclear damage for which a UK nuclear licensee is responsible. The limit for the operator is £140 million.

In the United States, the Price-Anderson Act has governed the insurance of the nuclear power industry since 1957. Owners of nuclear power plants are required to pay a premium each year for the maximum obtainable amount of private insurance ($450 million) for each licensed reactor unit. This primary or "first tier" insurance is supplemented by a second tier. In the event a nuclear accident incurs damages in excess of $450 million, each licensee would be assessed a prorated share of the excess up to $121,255,000. With 104 reactors currently licensed to operate, this secondary tier of funds contains about $12.61 billion. This results in a maximum combined primary+secondary coverage amount of up to $13.06 billion for a hypothetical single-reactor incident. If 15 percent of these funds are expended, prioritization of the remaining amount would be left to a federal district court. If the second tier is depleted, Congress is committed to determine whether additional disaster relief is required. In July 2005, Congress extended the Price-Anderson Act to newer facilities.

The Vienna Convention on Civil Liability for Nuclear Damage and the Paris Convention on Third Party Liability in the Field of Nuclear Energy put in place two similar international frameworks for nuclear liability. The limits for the conventions vary. The Vienna convention was adapted in 2004 to increase the operator liability to €700 million per incident, but this modification is not yet ratified.

Cost per kWh

The cost per unit of electricity produced (kWh) will vary according to country, depending on costs in the area, the regulatory regime and consequent financial and other risks, and the availability and cost of finance. Costs will also depend on geographic factors such as availability of cooling water, earthquake likelihood, and availability of suitable power grid connections. So it is not possible to accurately estimate costs on a global basis.

Commodity prices rose in 2008, and so all types of plants became more expensive than previously calculated. In June 2008 Moody's estimated that the cost of installing new nuclear capacity in the United States might possibly exceed $7,000/KWe in final cost. In comparison, the reactor units already under construction in China have been reported with substantially lower costs due to significantly lower labour rates.

In 2009, MIT updated its 2003 study, concluding that inflation and rising construction costs had increased the overnight cost of nuclear power plants to about $4,000/kWe, and thus increased the power cost to $0.084/kWh. The 2003 study had estimated the cost as $0.067/kWh.

A 2013 study indicates that the cost competitiveness of nuclear power is "questionable" and that public support will be required if new power stations are to be built within liberalized electricity markets.

In 2014, the US Energy Information Administration estimated the levelized cost of electricity from new nuclear power plants going online in 2019 to be $0.096/kWh before government subsidies, comparable to the cost of electricity from a new coal-fired power plant without carbon capture, but higher than the cost from natural gas-fired plants.

In 2019 the US EIA revised the levelized cost of electricity from new advanced nuclear power plants going online in 2023 to be $0.0775/kWh before government subsidies, using a regulated industry 4.3% cost of capital (WACC - pre-tax 6.6%) over a 30-year cost recovery period. Financial firm Lazard also updated its levelized cost of electricity report costing new nuclear at between $0.118/kWh and $0.192/kWh using a commercial 7.7% cost of capital (WACC - pre-tax 12% cost for the higher-risk 40% equity finance and 8% cost for the 60% loan finance) over a 40 year lifetime.

Comparisons with other power sources

Nuke, coal, gas generating costs.png

Generally, a nuclear power plant is significantly more expensive to build than an equivalent coal-fueled or gas-fueled plant. If natural gas is plentiful and cheap operating costs of conventional power plants is less. Most forms of electricity generation produce some form of negative externality — costs imposed on third parties that are not directly paid by the producer — such as pollution which negatively affects the health of those near and downwind of the power plant, and generation costs often do not reflect these external costs.

A comparison of the "real" cost of various energy sources is complicated by a number of uncertainties:

  • The cost of climate change through emissions of greenhouse gases is hard to estimate. Carbon taxes may be enacted, or carbon capture and storage may become mandatory.
  • The cost of environmental damage caused by any energy source through land use (whether for mining fuels or for power generation), air and water pollution, solid waste production, manufacturing-related damages (such as from mining and processing ores or rare earth elements), etc.
  • The cost and political feasibility of disposal of the waste from reprocessed spent nuclear fuel is still not fully resolved. In the United States, the ultimate disposal costs of spent nuclear fuel are assumed by the U.S. government after producers pay a fixed surcharge.
  • Operating reserve requirements are different for different generation methods. When nuclear units shut down unexpectedly they tend to do so independently, so the "hot spinning reserve" must be at least the size of the largest unit. On the other hand, some renewable energy sources (such as solar/wind power) are intermittent power sources with uncontrollably varying outputs, so the grid will require a combination of demand response, extra long-range transmission infrastructure, and large-scale energy storage. (Some firm renewables such as hydroelectricity have a storage reservoir and can be used as reliable back-up power for other power sources.)
  • Potential governmental instabilities in the plant's lifetime. Modern nuclear reactors are designed for a minimum operational lifetime of 60 years (extendible to 100+ years), compared to the 40 years (extendible to 60+ years) that older reactors were designed for.
  • Actual plant lifetime (to date, no nuclear plant has been shut down solely due to reaching its licensed lifetime. Over 87 reactors in the United States have been granted extended operating licenses to 60 years of operation by the NRC as of December 2016, and subsequent license renewals could extend that to 80 years. Modern nuclear reactors are also designed to last longer than older reactors as outlined above, allowing for even further increased plant lifetimes.)
  • Due to the dominant role of initial construction costs and the multi-year construction time, the interest rate for the capital required (as well as the timeline that the plant is completed in) has a major impact on the total cost of building a new nuclear plant.

Lazard's report on the estimated levelized cost of energy by source (10th edition) estimated unsubsidized prices of $97–$136/MWh for nuclear, $50–$60/MWh for solar PV, $32–$62/MWh for onshore wind, and $82–$155/MWh for offshore wind.

However, the most important subsidies to the nuclear industry do not involve cash payments. Rather, they shift construction costs and operating risks from investors to taxpayers and ratepayers, burdening them with an array of risks including cost overruns, defaults to accidents, and nuclear waste management. This approach has remained remarkably consistent throughout the nuclear industry's history, and distorts market choices that would otherwise favor less risky energy investments.

In 2011, Benjamin K. Sovacool said that: "When the full nuclear fuel cycle is considered — not only reactors but also uranium mines and mills, enrichment facilities, spent fuel repositories, and decommissioning sites — nuclear power proves to be one of the costliest sources of energy".

In 2014, Brookings Institution published The Net Benefits of Low and No-Carbon Electricity Technologies which states, after performing an energy and emissions cost analysis, that "The net benefits of new nuclear, hydro, and natural gas combined cycle plants far outweigh the net benefits of new wind or solar plants", with the most cost effective low carbon power technology being determined to be nuclear power. Moreover, Paul Joskow of MIT maintains that the "Levelized cost of electricity" (LCOE) metric is a poor means of comparing electricity sources as it hides the extra costs, such as the need to frequently operate back up power stations, incurred due to the use of intermittent power sources such as wind energy, while the value of baseload power sources are underpresented.

A 2017 focused response to these claims, particularly "baseload" or "back up", by Amory Lovins in 2017, countered with statistics from operating grids.

Other economic issues

Kristin Shrader-Frechette analysed 30 papers on the economics of nuclear power for possible conflicts of interest. She found of the 30, 18 had been funded either by the nuclear industry or pro-nuclear governments and were pro-nuclear, 11 were funded by universities or non-profit non-government organisations and were anti-nuclear, the remaining 1 had unknown sponsors and took the pro-nuclear stance. The pro-nuclear studies were accused of using cost-trimming methods such as ignoring government subsidies and using industry projections above empirical evidence where ever possible. The situation was compared to medical research where 98% of industry sponsored studies return positive results.

Nuclear power plants tend to be competitive in areas where other fuel resources are not readily available — France, most notably, has almost no native supplies of fossil fuels. France's nuclear power experience has also been one of paradoxically increasing rather than decreasing costs over time.

Making a massive investment of capital in a project with long-term recovery might affect a company's credit rating.

A Council on Foreign Relations report on nuclear energy argues that a rapid expansion of nuclear power may create shortages in building materials such as reactor-quality concrete and steel, skilled workers and engineers, and safety controls by skilled inspectors. This would drive up current prices. It may be easier to rapidly expand, for example, the number of coal power plants, without this having a large effect on current prices.

Existing nuclear plants generally have a somewhat limited ability to significantly vary their output in order to match changing demand (a practice called load following). However, many BWRs, some PWRs (mainly in France), and certain CANDU reactors (primarily those at Bruce Nuclear Generating Station) have various levels of load-following capabilities (sometimes substantial), which allow them to fill more than just baseline generation needs. Several newer reactor designs also offer some form of enhanced load-following capability. For example, the Areva EPR can slew its electrical output power between 990 and 1,650 MW at 82.5 MW per minute.

The number of companies that manufacture certain parts for nuclear reactors is limited, particularly the large forgings used for reactor vessels and steam systems. In 2010, only four companies (Japan Steel Works, China First Heavy Industries, Russia's OMZ Izhora and Korea's Doosan Heavy Industries) manufacture pressure vessels for reactors of 1100 MWe or larger. Some have suggested that this poses a bottleneck that could hamper expansion of nuclear power internationally, however, some Western reactor designs require no steel pressure vessel such as CANDU derived reactors which rely on individual pressurized fuel channels. The large forgings for steam generators — although still very heavy — can be produced by a far larger number of suppliers.

For a country with both a nuclear power industry and a nuclear arms industry, synergies between the two can favor a nuclear power plant with an otherwise uncertain economy. For example, in the United Kingdom researchers have informed MPs that the government was using the Hinkley Point C project to cross-subsidise the UK military's nuclear-related activity by maintaining nuclear skills. In support of that, researchers from the University of Sussex Andy Stirling and Phil Johnstone stated that the costs of the Trident nuclear submarine programme would be prohibitive without “an effective subsidy from electricity consumers to military nuclear infrastructure”.

Recent trends

Brunswick Nuclear Plant discharge canal
 

The nuclear power industry in Western nations has a history of construction delays, cost overruns, plant cancellations, and nuclear safety issues despite significant government subsidies and support. In December 2013, Forbes magazine reported that, in developed countries, "reactors are not a viable source of new power". Even in developed nations where they make economic sense, they are not feasible because nuclear's “enormous costs, political and popular opposition, and regulatory uncertainty”. This view echoes the statement of former Exelon CEO John Rowe, who said in 2012 that new nuclear plants “don’t make any sense right now” and won't be economically viable in the foreseeable future. John Quiggin, economics professor, also says the main problem with the nuclear option is that it is not economically-viable. Quiggin says that we need more efficient energy use and more renewable energy commercialization. Former NRC member Peter A. Bradford and Professor Ian Lowe have recently made similar statements. However, some "nuclear cheerleaders" and lobbyists in the West continue to champion reactors, often with proposed new but largely untested designs, as a source of new power.

Significant new build activity is occurring in developing countries like South Korea, India and China. China has 25 reactors under construction, 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.

The 1.6 GWe EPR reactor is being built in Olkiluoto Nuclear Power Plant, Finland. A joint effort of French AREVA and German Siemens AG, it will be the largest pressurized water reactor (PWR) in the world. The Olkiluoto project has been claimed to have benefited from various forms of government support and subsidies, including liability limitations, preferential financing rates, and export credit agency subsidies, but the European Commission's investigation didn't find anything illegal in the proceedings. However, as of August 2009, the project is "more than three years behind schedule and at least 55% over budget, reaching a total cost estimate of €5 billion ($7 billion) or close to €3,100 ($4,400) per kilowatt". Finnish electricity consumers interest group ElFi OY evaluated in 2007 the effect of Olkiluoto-3 to be slightly over 6%, or €3/MWh, to the average market price of electricity within Nord Pool Spot. The delay is therefore costing the Nordic countries over 1.3 billion euros per year as the reactor would replace more expensive methods of production and lower the price of electricity.

Russia has launched the world's first floating nuclear power plant. The £100 million vessel, the Akademik Lomonosov, is the first of seven plants (70 MWe per ship) that Moscow says will bring vital energy resources to remote Russian regions. Startup of the first of the ships two reactors was announced in December 2018.

Following the Fukushima nuclear disaster in 2011, costs are likely to go up for currently operating and new nuclear power plants, due to increased requirements for on-site spent fuel management and elevated design basis threats. After Fukushima, the International Energy Agency halved its estimate of additional nuclear generating capacity built by 2035.

Many license applications filed with the U.S. Nuclear Regulatory Commission for proposed new reactors have been suspended or cancelled. As of October 2011, plans for about 30 new reactors in the United States have been reduced to 14. There are currently five new nuclear plants under construction in the United States (Watts Bar 2, Summer 2, Summer 3, Vogtle 3, Vogtle 4). Matthew Wald from The New York Times has reported that "the nuclear renaissance is looking small and slow".

In 2013, four aging, uncompetitive reactors were permanently closed in the US: San Onofre 2 and 3 in California, Crystal River 3 in Florida, and Kewaunee in Wisconsin. The Vermont Yankee plant closed in 2014. New York State is seeking to close Indian Point Nuclear Power Plant, in Buchanan, 30 miles from New York City. The additional cancellation of five large reactor uprates (Prairie Island, 1 reactor, LaSalle, 2 reactors, and Limerick, 2 reactors), four by the largest nuclear company in the United States, suggest that the nuclear industry faces "a broad range of operational and economic problems".

As of July 2013, economist Mark Cooper has identified some US nuclear power plants that face particularly significant challenges to their continued operation due to regulatory policies. These are Palisades, Fort Calhoun (meanwhile closed for economical reasons), Nine Mile Point, Fitzpatrick, Ginna, Oyster Creek (same as Ft. Calhoun), Vermont Yankee (same as Ft. Calhoun), Millstone, Clinton, Indian Point. Cooper said the lesson here for policy makers and economists is clear: "nuclear reactors are simply not competitive". An 2017 analysis by Bloomberg showed that over half of U.S. nuclear plants were running at a loss, first of all those at a single unit site.

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