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Small Modular Reactors for Nuclear Power: Hope or Mirage?

Nuclear Monitor Issue: 
Prof. M. V. Ramana ‒ Simons Chair in Disarmament, Global and Human Security, University of British Columbia, Vancouver.

In October 2017, just after Puerto Rico was battered by Hurricane Maria, US Secretary of Energy Rick Perry asked the audience at a conference on clean energy in Washington, D.C.: "Wouldn't it make abundant good sense if we had small modular reactors that literally you could put in the back of a C-17, transport to an area like Puerto Rico, push it out the back end, crank it up and plug it in? ... It could serve hundreds of thousands".1

As exemplified by Secretary Perry's remarks, small modular reactors (SMRs) have been suggested as a way to supply electricity for communities that inhabit islands or in other remote locations.

More generally, many nuclear advocates have suggested that SMRs can deal with all the problems confronting nuclear power, including unfavorable economics, risk of severe accidents, disposing of radioactive waste and the linkage with weapons proliferation. Of these, the key problem responsible for the present status of nuclear energy has been its inability to compete economically with other sources of electricity. As a result, the share of global electricity generated by nuclear power has dropped from 17.5% in 1996 to 10.5% in 2016 and is expected to continue falling.

The inability of nuclear power to compete economically results from two related problems. The first problem is that building a nuclear reactor requires high levels of capital, well beyond the financial capacity of a typical electricity utility, or a small country. This is less difficult for state-owned entities in large countries like China and India, but it does limit how much nuclear power even they can install.

The second problem is that, largely because of high construction costs, nuclear energy is expensive. Electricity from fossil fuels, such as coal and natural gas, has been cheaper historically ‒ especially when costs of natural gas have been low, and no price is imposed on carbon. But, in the past decade, wind and solar energy, which do not emit carbon dioxide either, have become significantly cheaper than nuclear power. As a result, installed renewables have grown tremendously, in drastic contrast to nuclear energy.2

How are SMRs supposed to change this picture? As the name suggests, SMRs produce smaller amounts of electricity compared to currently common nuclear power reactors. A smaller reactor is expected to cost less to build. This allows, in principle, smaller private utilities and countries with smaller GDPs to invest in nuclear power. While this may help deal with the first problem, it actually worsens the second problem because small reactors lose out on economies of scale. Larger reactors are cheaper on a per megawatt basis because their material and work requirements do not scale linearly with generation capacity.

SMR proponents argue that they can make up for the lost economies of scale by savings through mass manufacture in factories and resultant learning. But, to achieve such savings, these reactors have to be manufactured by the thousands, even under very optimistic assumptions about rates of learning.3 Rates of learning in nuclear power plant manufacturing have been extremely low; indeed, in both the United States and France, the two countries with the highest number of nuclear plants, costs rose with construction experience.

For high learning rates to be achieved, there must be a standardized reactor built in large quantities. Currently dozens of SMR designs are at various stages of development; it is very unlikely that one, or even a few designs, will be chosen by different countries and private entities, discarding the vast majority of designs that are currently being invested in. All of these unlikely occurrences must materialize if small reactors are to become competitive with large nuclear power plants, which are themselves not competitive.

There is a further hurdle to be overcome before these large numbers of SMRs can be built. For a company to invest in a factory to manufacture reactors, it would have to be confident that there is a market for them. This has not been the case and hence no company has invested large sums of its own money to commercialize SMRs. An example is the Westinghouse Electric Company, which worked on two SMR designs, and tried to get funding from the US Department of Energy (DOE). When it failed in that effort, Westinghouse stopped working on SMRs and decided to focus its efforts on marketing the AP1000 reactor and the decommissioning business. Explaining this decision, Danny Roderick, then president and CEO of Westinghouse, announced: "The problem I have with SMRs is not the technology, it's not the deployment ‒ it's that there's no customers. ... The worst thing to do is get ahead of the market".4

Given this state of affairs, it should not be surprising that no SMR has been commercialized. Timelines have been routinely set back. In 2001, for example, a DOE report on prevalent SMR designs concluded that "the most technically mature small modular reactor (SMR) designs and concepts have the potential to be economical and could be made available for deployment before the end of the decade provided that certain technical and licensing issues are addressed". Nothing of that sort happened; there is no SMR design available for deployment in the United States so far.

Similar delays have been experienced in other countries too. In Russia, the first SMR that is expected to be deployed is the KLT-40S, which is based on the design of reactors used in the small fleet of nuclear-powered icebreakers that Russia has operated for decades. This programme, too, has been delayed by more than a decade and the estimated costs have ballooned.2

South Korea even licensed an SMR for construction in 2012 but no utility has been interested in constructing one, most likely because of the realization that the reactor is too expensive on a per-unit generating-capacity basis. Even the World Nuclear Association stated: "KAERI planned to build a 90 MWe demonstration plant to operate from 2017, but this is not practical or economic in South Korea" (my emphasis).

Likewise, China is building one twin-reactor high-temperature demonstration SMR and some SMR feasibility studies are underway5, but plans for 18 additional SMRs have been "dropped" according to the World Nuclear Association, in part because the estimated cost of generating electricity is significantly higher than the generation cost at standard-sized light-water reactors.6

On the demand side, many developing countries claim to be interested in SMRs but few seem to be willing to invest in the construction of one. Although many agreements and memoranda of understanding have been signed, there are still no plans for actual construction. Good examples are the cases of Jordan, Ghana and Indonesia, all of which have been touted as promising markets for SMRs, but none of which are buying one.

Another potential market that is often proffered as a reason for developing SMRs is small and remote communities. There again, the problem is one of numbers. There are simply not enough remote communities, with adequate purchasing capacity, to be able to make it financially viable to manufacture SMRs by the thousands so as to make them competitive with large reactors, let alone other sources of power. Neither nuclear reactor companies, nor any governments that back nuclear power, are willing to spend the hundreds of millions, if not a few billions, of dollars to set up SMRs just so that these small and remote communities will have nuclear electricity.

Meanwhile, other sources of electricity supply, in particular combinations of renewables and storage technologies such as batteries, are fast becoming cheaper. It is likely that they will become cheap enough to produce reliable and affordable electricity, even for these remote and small communities ‒ never mind larger, grid-connected areas ‒ well before SMRs are deployable, let alone economically competitive.

Reprinted with minor editing from National University of Singapore, ESI Bulletin, Vol.10, Issue 6, Dec. 2017.

1. Rod Adams, 29 Sept 2017, 'Perry's Vision of Nuclear Generator Movable by Cargo Plane Successfully Tested During Kennedy Admin',
2. Mycle Schneider and Antony Froggatt, 2017, 'The World Nuclear Industry Status Report 2017', www.
3. Alexander Glaser et al., June 2015, 'Small Modular Reactors: A Window on Nuclear Energy', Energy Technology Distillate, no. 2 (Princeton, N.J.: Andlinger Center for Energy and the Environment at Princeton University),
4. Anya Litvak, 1 Feb 2014, 'Westinghouse Backs off Small Nuclear Plants',
5. World Nuclear Association, 19 Sept 2017, 'China plans further high temperature reactor innovation',

6. World Nuclear Association, 21 March 2016, 'First vessel installed in China's HTR-PM unit',

UK: Power from SMRs 30% more expensive than large reactors

Nuclear Monitor Issue: 
Jim Green ‒ Nuclear Monitor editor

Electricity from the first small modular reactor (SMR) in Britain would be 30% more expensive than power from large reactors according to a report by the consultancy Atkins for the UK Department for Business, Energy and Industrial Strategy, because of reduced economies of scale and the costs of deploying first-of-a-kind technology.1,2

The Atkins report said there is "a great deal of uncertainty with regards to the economics" of the smaller reactors.2 The report estimates that the levelized cost of electricity for an SMR based on a pressurized water reactor design would be £86‒124/MWh with a central estimate of £101/MWh, and adds this caveat: "However it is recognised that SMR is a new technology and there is a substantial risk that these costs will be higher than this if costs accumulate during development or if financing costs are initially higher than they are for large nuclear."2

Chris Lewis from the consultancy EY said: "While the study recognises that the economics to build SMRs are challenging, measures can be taken to achieve greater cost reduction through the standardisation of technology, greater modularisation, and the ability to standardise design and repeat manufacturing."1

The Department for Business, Energy and Industrial Strategy announced on December 7 that it is making available up to £56 million over the next three years to support R&D into SMRs and to assess their feasibility and accelerate the development of promising designs.3

The government support is a small fraction of the funding required to develop SMRs. Nearly US$500 million was wasted on the mPower SMR project in the US ‒ including US$111 of government funding ‒ before the project was abandoned.4

And the £56 million on offer in the UK is a small fraction of support promised in 2015, when chancellor George Osborne said that at least £250m would be spent by 2020 on an "ambitious" programme to "position the UK as a global leader in innovative nuclear technologies".5

Industry sources told the Guardian that the government funding is a relatively small sum and they are unsure whether it will be enough to make a difference. "It's a pretty half-hearted, incredibly British, not-quite-good-enough approach," one said.4 An energy industry source questioned how credible most of the SMR developers were: "Almost none of them have got more than a back of a fag packet design drawn with a felt tip."5

Paul Dorfman, a research fellow at University College London, said: "The real question the government must ask is this: given the ongoing steep reduction in all renewable energy costs, and since SMR research and development is still very much ongoing, by the time SMRs comes to market, can they ever be cost competitive with renewable energy? The simple answer to that is a resounding no."5

Pete Roche wrote in September:6

"We now know thanks to Andy Stirling and Philip Johnstone of Sussex University that the government wants to use the civilian nuclear programme to generate expertise, and technology, for military use, especially reactors for Trident nuclear submarines. Lord Hutton gave the game away in his introduction to the SMR Consortium report when he wrote: 'A UK SMR programme would support all 10 'pillars' of the Government's Industrial Strategy and assist in sustaining the skills required for the Royal Navy's submarine programme.'

"Senior civil servants revealed that the government's decision to build a new generation of civil nuclear power stations starting with Hinkley Point is linked to maintaining enough skills to keep Britain's nuclear deterrent. The disclosure came at a hearing of the Commons Public Accounts Committee looking at the huge cost of building Hinkley Point power station which critics see as uneconomic and not properly costed.

"Stephen Lovegrove told the committee 'I was in regular discussion with Jon Thompson, former Permanent Secretary at the MOD, to say that as a nation we are going into a fairly intense period of nuclear activity … We are building the new SSBNs (nuclear armed nuclear submarines) and completing the Astutes … We are completing the build of the nuclear submarines which carry conventional weaponry. We have at some point to renew the warheads, so there is very definitely an opportunity here for the nation to grasp in terms of building up its nuclear skills.'

"With regard to Hinkley, Stirling and Johnstone say there is a 'remarkable persistence and intensity of UK Government attachments to what is increasingly recognised as an economically untenable project.' The persistence of this nuclear attachment looks to be at least partly due to a perceived need to subsidise the costs of operating and renewing the UK nuclear-propelled submarine fleet."


1. Adam Vaughan, 8 Dec 2017, 'Power from mini nuclear plants 'would cost more than from large ones'',

2. Atkins, 21 July 2016, 'SMR Techno-Economic Assessment Project 1: Comprehensive Analysis and Assessment Techno-Economic Assessment, Final Report, Volume 1, For The Department of Energy and Climate Change',

See also UK Department for Business, Energy & Industrial Strategy, 'Small Modular Reactors: Techno-Economic Assessment',

3. World Nuclear News, 7 Dec 2017, 'UK to support 'next-generation' nuclear technology',

4. Nuclear Monitor #840, 21 March 2017, 'U.S. small reactor project just got smaller',

5. Adam Vaughan, 4 Dec 2017, 'UK government to release funding for mini nuclear power stations',

6. Pete Roche, Nov 2017, 'SMRs', NuClear News, No.101,

Small nuclear power reactors for Canada: Future or folly?

Nuclear Monitor Issue: 
M.V. Ramana ‒ Liu Institute for Global Issues, University of British Columbia

Nuclear energy companies are proposing small nuclear reactors as a safer and cheaper source of electricity.1 In June, Canadian Nuclear Laboratories put out a "call for a discussion around Small Modular Reactor (SMRs) in Canada" and the role the organization "can play in bringing this technology to market."2

The news release asserts that SMRs are "a potential alternative to large-scale nuclear reactors," would be effective at "decreasing up-front capital costs through simpler, less complex plants" and are "inherently safe" designs.2 All of this warrants examination.

As a physicist who has researched and written about various policy issues related to nuclear energy and different nuclear reactor designs for nearly two decades, I believe that one should be skeptical of these claims.

SMRs produce small amounts of electricity compared to currently common nuclear power reactors. In Canada, the last set of reactors commissioned were the four at Darlington, east of Toronto, which entered service between 1990 and 1993. These are designed to feed 878 megawatts into the electric grid.

In contrast, the first two nuclear power reactors commissioned in Canada were the Nuclear Power Demonstration reactor at Rolphton, Ont., in 1962, and Douglas Point, Ont., in 1968. These fed 22 and 206 megawatts respectively to the grid.

In other words, reactors have increased in size and power-generating capacity over time. For perspective, normal summer-time peak demand for electricity in Ontario is estimated at over 22,000 megawatts.3

Cost considerations key

The reason for the increase in reactor output is simple: Nuclear power has always been an expensive way to generate electricity. Historically, small reactors built in the United States all shut down early because they couldn't compete economically.4 One of the few ways that nuclear power plant operators could reduce costs was to capitalize on economies of scale ‒ taking advantage of the fact that many of the expenses associated with constructing and operating a reactor do not change in proportion to the power generated.

Building a 800-megawatt reactor requires less than four times the quantity of concrete or steel as a 200-megawatt reactor, and does not need four times as many people to operate it. But it does generate four times as much electricity, and revenue.

Small modular reactors are even smaller. The NuScale reactor being developed by NuScale Power in the United States is to feed just 47.5 megawatts into the grid.5 This reduction is chiefly due to the main practical problem with nuclear power: reactors are expensive to build.

Consider the experience in Ontario: In 2008, the province's government asked reactor vendors to bid for the construction of two more reactors at the Darlington site. The bid from Atomic Energy of Canada Ltd. was reported to be $26 billion for two 1200-megawatt CANDU reactors ‒ more than three times what the government had assumed.6 The province abandoned its plans.7

Not surprisingly, with costs so high, few reactors are being built. The hope offered by the nuclear industry is that going back to building smaller reactors might allow more utilities to invest in them.

NuScale Power says a 12-unit version of its design that feeds 570 MW to the grid will cost "less than $3 billion."8 But because the reactor design is far from final, the figure is not reliable. There is a long and well-documented history of reactors being much more expensive than originally projected.9 This year, Westinghouse Electric Company ‒ historically the largest builder of nuclear power plants in the world ‒ filed for Chapter 11 bankruptcy protection in the United States precisely because of such cost overruns.10

Cost overruns aside, smaller reactors might be cheaper but they also produce much less electricity and revenue. As a result, generating each unit of electricity will be more expensive.

Design aims to reduce costs

The second part of the SMR abbreviation, "Modular," is again an attempt to control costs. The reactor is to be mostly constructed within a factory with limited assembly of factory-fabricated "modules" at the site of the power plant itself. It may even be possible to completely build a SMR in a factory and ship it to the reactor site.

Modular construction has been increasingly incorporated into all nuclear reactor building, including large reactors. However, since some components of a large reactor are physically voluminous, they have to be assembled on site. Again, modularity is no panacea for cost increases, as Westinghouse found out in recent years.11

Safety in scale?

SMR developers say the technology poses a lower risk of accidents, as Canadian Nuclear Laboratories suggests when it asserts "inherent safety" as a property of SMRs. Intuitively, smaller reactors realize safety benefits since a lower power reactor implies less radioactive material in the core, and therefore less energy potentially released in an accident.

The problem is that safety is only one priority for designers. They must also consider about other priorities, including cost reductions. These priorities drive reactor designs in different directions, making it practically impossible to optimize all of them simultaneously.12

The main priority preventing safe deployment is economics. Most commercial proposals for SMRs involve cost-cutting measures, such as siting multiple reactors in close proximity. This increases the risk of accidents, or the impact of potential accidents on people nearby.

At Japan's Fukushima Daiichi plant, explosions at one reactor damaged the spent fuel pool in a co-located reactor. Radiation leaks from one unit made it difficult for emergency workers to approach the other units.

Looking ahead

The future for nuclear energy in Canada is not rosy. Canada's National Energy Board's latest Canada's Energy Future 2016 report that projects supply and demand to the year 2040 states: "No new nuclear units are anticipated to be built in any province during the projection period."13 It notes annual nuclear generation is forecast to decline nearly 12.5% from 98 terawatt-hours in 2014 to 77 in 2040.

Promoters of SMRs argue that investing in small reactors will change this bleak picture. But technical and economic factors, as well as the experience of small nuclear reactors built in an earlier era, all suggest that this is a mislaid hope.

Reprinted from The Conversation: 'Small nuclear power reactors: Future or folly?', 25 July 2017,















U.S. small reactor project just got smaller

Nuclear Monitor Issue: 
Jim Green ‒ Nuclear Monitor editor

The mPower small modular reactor (SMR) project in the USA just got much smaller: it has been abandoned.

mPower was conceived in 2008 and announced to the world in June 2009. In July 2010, Babcock & Wilcox announced an alliance with Bechtel called Generation mPower. At the same time, Babcock & Wilcox announced that it would build an mPower test facility in Virginia, part-funded by a US$5 million grant from the Virginia Tobacco Indemnification and Community Revitalisation Commission.1

Generation mPower planned to apply to the Nuclear Regulatory Commission (NRC) for design certification by 2013.1 The company aimed for NRC certification and a reactor construction permit in 2018, and commercial operation of the first two units in 2022.2

The idea was to produce scaled-down (195 MWe) pressurized light water reactors (PWR), drawing on decades of worldwide experience with (larger) PWRs and thus making NRC licensing simpler and quicker.3

Experienced, cashed-up companies ... a conventional reactor design ... R&D funding support from Virginia and from the federal Department of Energy ... what could go wrong?

It didn't take long for the project to fall apart. In 2013 Babcock & Wilcox said it intended to sell a majority stake in the mPower joint venture, but in February 2014 announced it was unable to find a buyer. In April 2014, Babcock & Wilcox announced it was sharply reducing investment in mPower to US$15 million annually, citing the inability "to secure significant additional investors or customer engineering, procurement and construction contracts to provide the financial support necessary to develop and deploy mPower reactors".1

More than 200 engineers, project managers, administrators, and sales-people were sacked in 2014.4

The Tennessee Valley Authority had been named as a lead customer and plans were developed to build up to six mPower reactors at TVA's Clinch River site at Oak Ridge, Tennessee.5 But in 2014, TVA ended the agreement to share design and licensing costs.

In November 2012, the US Department of Energy (DOE) announced that it would subsidize mPower development in a five-year cost-share agreement. The DOE's contribution would be capped at US$226 million, of which US$111 million was subsequently paid. That funding tap was switched off after Generation mPower downsized the project in 2014, but the company was not required to repay any of the DOE funding.2

The Generation mPower companies spent more than US$375 million on mPower to February 2016.2 Add that to the DOE's US$111 million contribution, and overall expenditure was nudging US$500 million.

In March 2016, Babcock & Wilcox and Bechtel came to an arrangement whereby Bechtel would attempt to secure further funding from third parties, including the DOE.2 However those efforts have been abandoned. On 3 March 2017, Bechtel notified Babcock & Wilcox that it was unable to secure sufficient funding and was invoking a settlement provision to terminate the joint agreement. Generation mPower will terminate the program in the next few months.3

Bechtel spokesperson Fred deSousa said: "Bringing a new reactor program through the design, engineering and regulatory process is a very complex and expensive proposition. It needed a plant owner with an identified location and an investor willing to wait a significant period of time for a return, and these were not available."6

Rod Adams ‒ who worked for B&W mPower as the Process and Procedure Development Lead from 2010 to 2013 ‒ gives some reasons for the demise of mPower:3

  • The financial crisis of 2008.
  • The continuing reduction in natural gas prices.
  • Management challenges associated with a fundamentally unequal partnership between two large, established companies, each with their own culture.
  • "The aggressive effort to market the Fukushima events as a nuclear catastrophe in order to suppress a growing interest in nuclear energy development".
  • "The entry of activist investors that purchased a large portion of B&W's stock and forced a major reevaluation of the project and the overall corporate structure".

Adams' statement about aggressive efforts to market Fukushima as a nuclear catastrophe is a cheap shot at environmentalists and other nuclear critics. His statement about "activist investors" is more intriguing. That's a story he discussed in a 2014 article.4 He notes that the February 2014 announcement to sharply reduce investment in mPower followed the purchase of Babcock & Wilcox shares by Wall Street investment funds. Those investment funds purchased enough stock to impose a restructuring plan that directed spending away from mPower. Their motives, according to Adams, were to prioritize short-term profits over medium-term investments, and to protect their investments in fossil fuels by killing off a potential competitor. And their statements about a lack of customer and investor interest were a concocted cover story.

So mPower was wedged between aggressive anti-nuclear marketeers and fossil-fueled corporate interests. Perhaps. Adams also offers a tendentious conspiracy theory about a "sabotage effort from within the nuclear industry".4

A future for SMRs?

SMRs continue to be the subject of endless hype. There's quite a bit of R&D ‒ in the US, the UK, South Korea, China and elsewhere. But only a few SMRs are under construction: one in Argentina, a twin-reactor floating nuclear power plant in Russia, and three SMRs in China (including two high-temperature gas-cooled reactors).2

The broad picture for SMRs is much the same as that for fast neutron reactors: lots of hot air, some R&D, but few concrete plans and even fewer concrete pours.7 Michael McGough from NuScale, a US SMR company, said: "It's one thing to talk about it. It's another thing to actually build it and do it."8

A February 2017 Lloyd's Register report surveyed almost 600 energy industry professionals and experts and the dominant view was that SMRs have a "low likelihood of eventual take-up, and will have a minimal impact when they do arrive".9,10 Likewise, a 2014 Nuclear Energy Insider report, drawing on interviews with more than 50 "leading specialists and decision makers", pointed to a "pervasive sense of pessimism" resulting from abandoned and scaled-back SMR programs.11

No company or country is seriously considering building the massive supply chain that is at the very essence of the concept of SMRs ‒ mass, modular construction. Yet without that supply chain, SMRs will be expensive curiosities. As pro-nuclear commentator Dan Yurman noted in January 2016, "the real challenge will be to book enough orders to bring investors to the table to build factories to turn out SMRs on a cost effective production line basis."12

Thomas W. Overton, associate editor of POWER magazine, wrote in a September 2014 article: "At the graveyard wherein resides the "nuclear renaissance" of the 2000s, a new occupant appears to be moving in: the small modular reactor (SMR). ... The SMR concept disdains ... economies of scale in favor of others: large-scale standardized manufacturing that will churn out dozens, if not hundreds, of identical plants, each of which would ultimately produce cheaper kilowatt-hours than large one-off designs. It's an attractive idea. But it's also one that depends on someone building that massive supply chain, since none of it currently exists. ... That money would presumably come from customer orders − if there were any."13

So how many orders would a manufacturer need to go the financial markets to get funding to build a supply chain to make lots of SMRs? Dan Yurman writes: "The answer, according to David Orr, head of nuclear business development for Rolls-Royce in the UK, ... is a minimum of about four dozen units and six dozen would be better. Those are high numbers which make some proponents of SMRs unhappy. The reason is this estimate means that turning out the first 50 or so SMRs for any firm in the business could be a high wire act."12

A recent article from two pro-nuclear lobby groups, Third Way and Breakthrough Institute, argues that with small reactor concepts, "there is ample opportunity for learning by doing and economies of multiples for several reactor classes and designs".14 But the mPower project cost close to US$500 million. That sort of expensive failure can't be repeated indefinitely.

NuScale has progressed further than mPower ‒ it recently submitted an application to the NRC for design certification. To get to this point has cost US$500 million and taken two million labor-hours over eight years.15 NRC certification will likely take an additional three years.15 NuScale estimates that by the time it gets through the NRC licensing process, it will have spent US$1 billion overall (including a significant DOE contribution for R&D).16

And then NuScale will face the problem that there is a long way from NRC certification to the completion of its first SMR, and further still from the first reactor to mass production for a mass market.

NuScale says the aim is to replace "economy-of-scale with economy-of-the-assembly-line".17 But the risk is that SMR developers will end up with neither. In the absence of a mass supply chain, costs will be exorbitant. The construction cost of Argentina's 25 MWe CAREM reactor is estimated at US$446 million, which equates to a whopping US$17.8 billion / gigawatt (GW).18 Estimated construction costs for the Russian floating SMR have increased more than four-fold and now equate to over US$10 billion / GW.19 For comparison, the estimated cost of the planned Hinkley Point EPR reactors in the UK is US$7 billion / GW or US$9.5 billion / GW including finance.


1. B&W mPower,

2. World Nuclear Association, March 2017, 'Small Nuclear Power Reactors',

3. Rod Adams, 13 March 2017, 'Bechtel And BWXT Quietly Terminate mPower Reactor Project',

4. Rod Adams, 9 May 2014, 'B&W mPower cover story about lack of interest is bogus',

5. World Nuclear News, 14 April 2014, 'Funding for mPower reduced',

6. Margaret Carmel, 15 March 2017, 'BWXT, Bechtel shelve mPower program',

7. Nuclear Monitor #831, 5 Oct 2016, 'The slow death of fast reactors',

8. John Fialka, 7 March 2017, 'In nuclear poker, who's betting on small reactors?',

9. Lloyd's Register, February 2017, 'Technology Radar – A Nuclear Perspective: Executive summary',

10. World Nuclear News, 9 Feb 2017, Nuclear more competitive than fossil fuels: report',

11. Nuclear Energy Insider, 2014, "Small Modular Reactors: An industry in terminal decline or on the brink of a comeback?",

12. Dan Yurman, 21 Jan 2016, 'The UK plans to become a global center for small nuclear reactors. Can it succeed?',

13. Thomas W. Overton, 1 Sept 2014, 'What Went Wrong with SMRs?',

14. Josh Freed, Todd Allen, Ted Nordhaus, and Jessica Lovering, 28 Feb 2017, 'Do We Need An Airbus for Nuclear?',

15. Andrew Follett, 17 March 2017, 'After Years Of Delays, Gov't Finally To Review 1st Advanced Nuclear Reactor',

16. 4 May 2016, 'NuScale announces roadmap for SMR operation at Idaho site by 2024',

17. NuScale, 'Construction Cost for a NuScale Nuclear Power Plant',

18. World Nuclear News, 10 Feb 2014, 'Construction of CAREM underway',

19. Charles Digges, 25 May 2015, 'New documents show cost of Russian floating nuclear power plant skyrockets',

Nuclear advocates fight back with wishful thinking

Nuclear Monitor Issue: 
Michael Mariotte − President of the Nuclear Information & Resource Service

It must be rough to be a nuclear power advocate these days: clean renewable energy is cleaning nuclear's clock in the marketplace; energy efficiency programs are working and causing electricity demand to remain stable and even fall in some regions; despite decades of industry effort radioactive waste remains an intractable problem; and Fukushima's fallout − both literal and metaphoric − continues to cast a pall over the industry's future.

Where new reactors are being built, they are − predictably − behind schedule and over-budget; while even many existing reactors, although their capital costs were paid off years ago, can't compete and face potential shutdown because of operating and maintenance costs that are proving to be too high to manage.

Not surprisingly, the nuclear industry is fighting back. After all, what other choice does it have? But a major new report by established nuclear advocates indicate that the only ammunition left in their arsenal is wishful thinking. The study, 'Projected Costs of Generating Electricity', is jointly produced by the International Energy Agency (IEA) and its sister organization in the OECD, the Nuclear Energy Agency (NEA).1

It's an update of a study last produced in 2010 and despite the headlines being pushed by the industry, which claim nuclear power is economically competitive with other generating technologies, it doesn't actually say that at all. But perhaps that's to be expected by an organization now headed by former US Nuclear Regulatory Commissioner William Magwood and devoted to the promotion of nuclear power.

As Jan Haverkamp of Greenpeace International explains:

"You can see the NEA's bias very clearly in slide 112 (part of the public presentation on the report's release), where the title is: "Nuclear: an attractive low-carbon technology in the absence of cost overruns and with low financing costs" ... which shows clearly where the problem is. To call this "attractive" but then sidelining two of the inherent financial issues with the resource is tendentious to say the least. Apart from not including costs like those for clean-up after severe accidents, an insecure cost idea of waste management, and a preferential liability capping scheme with government back-up."

Exactly. If you assume there are no economic problems with nuclear power, then it looks just great. The problem is that in real life, nuclear power's financing costs are not low − they are extremely high because nuclear reactors are considered, for good reason, by investors to be very risky undertakings. One reason they are risky, and thus incur high financing costs, is that they are notorious for their cost overruns.

As if to slap its Paris-based companion the NEA in its face with cold reality, Electricite de France underscored new nuclear power's fundamental economic problems, announcing that the EPR reactor it is building in Flamanville, France, is another year behind schedule and its cost is now projected at triple its original 2007 estimate.3

The IEA/NEA study calculates the levelized lifetime cost of electricity for reactors based on a 60-year lifespan at an 85% capacity factor, even though the study itself admits the global capacity factor in 2013 was only 82.4% and has dropped a bit since the 2010's study reference point of 2008. So the study thus assumes a lifetime that no reactor has yet reached, and that many reactors globally will not even attempt to reach (see below), at a capacity factor higher than has been attained and when the trend is in the opposite direction. Even manipulating the numbers like that, however, only gets the IEA/NEA back to its starting point of needing both the unattainable low financing costs and absence of cost overruns to make new nuclear appear economic.

As for that 60-year lifespan, while most U.S. reactors already have received license extensions allowing their 60-year operation, that is not the case globally (nor is it at all clear that a piece of paper allowing operation will be sufficient on either an economic or safety basis to enable operation). And a new report from a company called Globaldata projects that the number of reactors expected to seek license extensions globally will decline until 2025 (at least).4 Globaldata senior analyst Reddy Nagatham said: "This will be most notable in Europe, where the capacity of NPPs starting PLEX operations is expected to drop almost sevenfold from approximately 8.3 GW this year to 1.2 GW by the end of 2025."

Of course, the shorter a reactor's lifetime, the higher its lifetime cost of electricity will be.

As Greenpeace's Jan Haverkamp points out, the IEA/NEA appears to have a specific endgame in mind: "This study clearly targets the Paris COP [UN climate conference in December 2015] and tries to instill the idea that nuclear needs to get subsidies in the form of credit guarantees and price guarantees and then that will be the silver bullet."

And that brings us back to that more familiar refrain from the nuclear industry: give us more ratepayer bailouts and more taxpayer subsidies and everything will be just fine. The problem for the industry is that fewer and fewer people are singing that song.

Small modular reactors and Generation IV reactors

Nor should the industry look for help from the trendy new kids on the block: small modular reactors (SMRs) and Generation IV technologies. The report predicts that electricity costs from SMRs will typically be 50−100% higher than for current large reactors, although it holds out some hope that large volume production of SMRs could help reduce costs − if that large volume production is comprised of "a sufficiently large number of identical SMR designs ... built and replicated in factory assembly workshops." Not very likely unless the industry accepts a socialist approach to reactor manufacturing, which is even less likely than that the approach would lead to any significant cost savings.

As for Generation IV reactors, the report at its most optimistic can only say: "In terms of generation costs, generation IV technologies aim to be at least as competitive as generation III technologies ... though the additional complexity of these designs, the need to develop a specific supply chain for these reactors and the development of the associated fuel cycles will make this a challenging task."

So, at best the Generation IV reactors are aiming to be as competitive as the current − and economically failing − Generation III reactors. And even realizing that inadequate goal will be "challenging." The report might as well have recommended to Generation IV developers not to bother.

Another problem with the report is that the IEA − perhaps at the urging of the NEA − simply assumes that the electrical grid of the future will be the same as it is today, despite the rapid pace of change across the world but especially in the IEA's European home base.

In fact, if there is a real takeaway from the report, it is from the headline on the IEA's website rather than any nuclear publication: 'Joint IEA-NEA report details plunge in costs of producing electricity from renewables.'5

Yes, while the nuclear industry has been attempting to frame the report as good news for nuclear power, the real findings of the report are in the stunning drop in renewables costs. Onshore wind, according to the report, is the cheapest power source of any examined. Solar power, except residential rooftop, is increasingly competitive and will drop further, unencumbered by the high financing charges and cost overruns experienced by nuclear.

It's good to see IEA say something favorable about renewables. As we reported last year, the organization has been notoriously wrong on the deployment of renewables over the years, greatly underprojecting their growth and compiling a simply embarrassing record.6


1. International Energy Agency (IEA) and OECD Nuclear Energy Agency (NEA), 2015, 'Projected Costs of Generating Electricity':

Media release:

Executive Summary:

Purchase full report:


3. WNN, 3 Sept 2015, 'Flamanville EPR timetable and costs revised',

4. Phil Allan, 2 Sept 2015, 'Fukushima fallout leading to decline in nuclear generation',

5. IEA, 31 Aug 2015, 'Joint IEA-NEA report details plunge in costs of producing electricity from renewables',

6. Michael Mariotte, 17 July 2014, 'IEA "experts" not particularly expert',

US Government Accountability Office pours cold water on advanced reactor concepts

Nuclear Monitor Issue: 
Jim Green - Nuclear Monitor editor

The US Government Accountability Office (GAO) has released a report on the status of small modular reactors (SMRs) and other new reactor concepts in the US.

Let's begin with the downbeat conclusion of the GAO report:

"While light water SMRs and advanced reactors may provide some benefits, their development and deployment face a number of challenges. Both SMRs and advanced reactors require additional technical and engineering work to demonstrate reactor safety and economics, although light water SMRs generally face fewer technical challenges than advanced reactors because of their similarities to the existing large LWR [light water] reactors. Depending on how they are resolved, these technical challenges may result in higher-cost reactors than anticipated, making them less competitive with large LWRs or power plants using other fuels. ...

"Both light water SMRs and advanced reactors face additional challenges related to the time, cost, and uncertainty associated with developing, certifying or licensing, and deploying new reactor technology, with advanced reactor designs generally facing greater challenges than light water SMR designs. It is a multi-decade process, with costs up to $1 billion to $2 billion, to design and certify or license the reactor design, and there is an additional construction cost of several billion dollars more per power plant.

"Furthermore, the licensing process can have uncertainties associated with it, particularly for advanced reactor designs. A reactor designer would need to obtain investors or otherwise commit to this development cost years in advance of when the reactor design would be certified or available for licensing and construction, making demand (and customers) for the reactor uncertain. For example, the price of competing power production facilities may make a nuclear plant unattractive without favorable rates set by a public authority or long term prior purchase agreements, and accidents such as Fukushima as well as the ongoing need for a long-term solution for spent nuclear fuel may affect the public perception of reactor safety. These challenges will need to be addressed if the capabilities and diversification of energy sources that light water SMRs and advanced reactors can provide are to be realized."

Many of the same reasons explain the failure of the Next Generation Nuclear Plant Project. Under the Energy Policy Act of 2005, the US Department of Energy (DoE) was to deploy a prototype 'next generation' reactor using advanced technology to generate electricity, produce hydrogen, or both, by the end of fiscal year 2021. However, in 2011, DoE decided not to proceed with the deployment phase of the project.

Small modular reactors

Four companies have considered developing SMRs in the US in recent years. NuScale has a cost-sharing agreement such that the DoE will pay as much as half of NuScale's costs − up to $217 million (€194m) over five years − for SMR design certification. NuScale expects to submit a design certification application to NRC in late 2016, and may begin operating its first SMR in 2023 or 2024. (However the timeframe is unrealistic, and the project may be abandoned − as other SMR projects have.)

The other three companies are a long way behind NuScale:

  • mPower, a subsidiary of Babcock & Wilcox, enjoyed a cost-sharing agreement with the DoE but in 2014 scaled back its R&D efforts because of a lack of committed customers and a lack of investors.
  • Holtec says it is continuing R&D work, but does not have a detailed schedule.
  • In 2014 Westinghouse suspended its efforts to certify its SMR design, because of a lack of committed customers (and the lack of a DoE cost-sharing agreement).

The GAO report states that the development of light water SMRs may proceed without serious difficulties as they are based on existing light water reactor technology. That said, standardization is a key pillar of SMR rhetoric, and members of an expert group convened by the GAO noted that component standardization has proven challenging for the construction of the larger Westinghouse AP1000 that has some modular components.

Another pillar of SMR rhetoric is mass production (to make them economic), and the development of a massive construction chain to allow for mass production is a radically different proposition to NuScale's plan to build just one reactor over the next decade.

Not-so-advanced reactor concepts

According to the GAO report, SMRs and new reactor concepts "face some common challenges such as long time frames and high costs associated with the shift from development to deployment − that is, in the construction of the first commercial reactors of a particular type."

The report notes the US government's generous financial support for utilities developing SMRs and advanced reactor concepts − DoE provided US$152.5 million (€137m) in fiscal year 2015 alone. Advanced reactor concepts attracting DoE largesse are the high temperature gas cooled reactor, the sodium cooled fast reactor, and to a lesser extent the molten salt reactor (specifically, a sub-type known as the fluoride salt cooled high temperature reactor).

DoE and Nuclear Regulatory Commission (NRC) officials do not expect applications for advanced reactors for at least five years. In other words, an application may (or may not) be submitted some time between five years and five centuries from now.

Advanced reactor designers told the GAO that they have been challenged to find investors due to the lengthy timeframe, costs, and uncertainty. Advanced reactor concepts face greater technical challenges than light water SMRs because of fundamental design differences. Thus designers have significantly more R&D issues to resolve, including in areas such as materials studies and fuel certification, coolant chemistry studies, and safety analysis. Some members of the expert group convened by the GAO noted a potential need for new test facilities to support this work. Furthermore, according to reactor designers, certifying or licensing an advanced reactor may be particularly time-consuming and difficult, adding to the already considerable economic uncertainty for the applicants.

The process of developing and certifying a specific reactor design can take 10 years or more for design work and nearly 3.5 years, as a best case, for NRC certification. Even that timeframe is more hope than expectation. Recent light water reactor design certifications, for the Westinghouse AP1000 and the GE Hitachi ESBWR, have taken about 15 and 11 years respectively. Both the AP1000 and ESBWR are modifications of long-established reactor types, so considerably longer timeframes can be expected for advanced concepts.

The cost to develop and certify a design can range from US$1−2 billion (€0.9−1.8b). Developers hope that costs can be reduced as they move from certification to the construction of a first-of-a-kind plant to the construction of multiple plants. But the GAO report notes that those hopes may be unfounded:

"[S]ome studies suggest that existing, large LWRs have not greatly benefitted from industry-wide standardization or learning to date for reasons including intermittent development and production. In fact, some studies have found that "reverse or negative learning" occurs when increased complexity or operation experience leads to newer safety standards. On a related point, another reactor designer said that the cost and schedule difficulties associated with building the first new design that has been certified by the NRC and started construction in the United States in three decades − the Westinghouse AP1000, a recently designed large LWR − have made it harder for light water SMRs to obtain financing because high-profile problems have made nuclear reactors in general less attractive. ... The AP1000 was the first new design that has been certified by the NRC and started construction in the United States in three decades. However, construction problems, including supply chain and regulatory issues, have resulted in cost and schedule increases."

US Government Accountability Office, July 2015, 'Nuclear Reactors: Status and challenges in development and deployment of new commercial concepts', GAO-15-652,

Small Modular Reactors: no solution for costs, safety and waste problems

Nuclear Monitor Issue: 

The same industry that promised that nuclear power would be "too cheap to meter" is now touting another supposed cure-all for America's power needs:  the small modular reactor (SMR).  The small modular reactor is being pitched by the nuclear power industry as a sort of production-line auto alternative to hand-crafted sports car, with supposed cost savings from the "mass manufacturing" of modestly sized reactors that could be scattered across the United States on a relatively quick basis. The facts about SMRs are far less rosy. 

Proponents of nuclear power are advocating for the development of small modular reactors (SMRs) as the solution to the problems facing large reactors, particularly soaring costs, safety, and radioactive waste.  “Small modular reactors” are defined by the US Department of Energy (DOE) as reactors that would produce 300MWe or less and are made in modules that can be transported. Unfortunately, small-scale reactors can’t solve these problems, and would likely exacerbate them.

There has been a proliferation of proposed Small Modular Reactor designs, but none have applied for certification by the Nuclear Regulatory Com­mission (NRC) yet. The NRC says that it expects to receive its first SMR design certification appli­cation in 2012. The factsheet addresses SMR designs for which the NRC may receive design certification applications in FY2011. It does not include some designs that are being researched but that are not on the NRC list, notably the travelling wave reactor. IEER will produce a separate report later in 2010 on this reactor.

Inherently more expensive?
SMR proponents claim that small size will en­able mass manufacture in a factory, enabling considerable savings relative to field construc­tion and assembly that is typical of large reac­tors. In other words, modular reactors will be cheaper because they will be more like as­sembly line cars than hand-made Lamborghi­nis.

In the case of reactors, however, several offsetting factors will tend to neutralize this advantage and make the costs per kilowatt of small reactors higher than large reactors. First, in contrast to cars or smart phones or similar widgets, the materials cost per kilowatt of a reactor goes up as the size goes down. This is because the surface area per kilowatt of capacity, which dominates materi­als cost, goes up as reactor size is decreased. Similarly, the cost per kilowatt of secondary containment, as well as independent systems for control, instrumentation, and emergency management, increases as size decreases. Cost per kilowatt also increases if each reac­tor has dedicated and independent systems for control, instrumentation, and emergency management. For these reasons, the nuclear industry has been building larger and larger reactors in an effort to try to achieve economies of scale and make nuclear power economically competitive.

Proponents argue that because these nuclear projects would consist of several smaller reactor modules instead of one large reactor, the construction time will be shorter and therefore costs will be reduced. How­ever, this argument fails to take into account the implications of installing many reactor modules in a phased manner at one site, which is the proposed approach at least for the United States. In this case, a large contain­ment structure with a single control room would be built at the beginning of the project that could accommodate all the planned capacity at the site. The result would be that the first few units would be saddled with very high costs, while the later units would be less expensive.

The realization of economies of scale would depend on the construction period of the entire project, possibly over an even longer time span than present large-reactor projects. If the later-planned units are not built, for instance due to slower growth than anticipated, the earlier units would likely be more expensive than present reactors, just from the diseconomies of the containment, site preparation, instrumentation and control system expenditures. Alternatively, a contain­ment structure and instrumentation and control could be built for each reactor. This would greatly increase unit costs and per kilo­watt capital costs. Some designs (such as the PBMR) propose no secondary containment, but this would increase safety risks.

These cost increases are unlikely to be offset even if the entire reactor is manufac­tured at a central facility and some economies are achieved by mass manufacturing com­pared to large reactors assembled on site.

Furthermore, estimates of low prices must be regarded with skepticism due to the history of past cost escalations for nuclear reactors and the potential for cost increases due to require­ments arising in the process of NRC certifica­tion. Some SMR designers are proposing that no prototype be built and that the necessary licensing tests be simulated. Whatever the process, it will have to be rigorous to ensure safety, especially given the history of some of proposed designs.

The cost picture for sodium-cooled reac­tors is also rather grim. They have typically been much more expensive to build than light water reactors, which are currently estimated to cost between $6,000 and $10,000 per kilowatt in the US. The costs of the last three large breeder reactors have varied wild­ly.

In 2008 dollars, the cost of the Japanese Monju reactor (the most recent) was $27,600 per kilowatt (electrical); French Superphénix (start up in 1985) was $6,300; and the Fast Flux Test Facility (startup in 1980) at Hanford was $13,800. This gives an average cost per kilowatt in 2008 dollars of about $16,000, without taking into account the fact that cost escalation for nuclear reactors has been much faster than inflation. In other words, while there is no recent US experience with construction of sodium-cooled reactors, one can infer that (i) they are likely to be far more expensive than light water reactors, (ii) the financial risk of building them will be much greater than with light water reactors due to high variation in cost from one project to another and the high variation in capacity fac­tors that might be expected.

Even at the lower end of the capital costs, for Superphénix, the cost of power generation was extremely high — well over a dollar per kWh since it operated so little. Monju, despite being the most expensive has generated essentially no electricity since it was commissioned in 1994. There is no comparable experience with potassium-cooled reactors, but the chemi­cal and physical properties of potassium are similar to sodium.

Increased safety and proliferation problems
Mass manufacturing raises a host of new safety, quality, and licensing concerns that the NRC has yet to address. For instance, the NRC may have to devise and test new licensing and inspection procedures for the manufacturing facilities, including inspec­tions of welds and the like. There may have to be a process for recalls in case of major de­fects in mass-manufactured reactors, as there is with other mass-manufactured products from cars to hamburger meat. It is unclear how recalls would work, especially if transpor­tation offsite and prolonged work at a repair facility were required.

Some vendors, such as PBMR (Pty) Ltd. and Toshiba, are proposing to manufacture the reactors in foreign countries. In order to reduce costs, it is likely that manufacturing will move to countries with cheaper labor forces, such as China, where severe quality problems have arisen in many products from drywall to infant formula to rabies vaccine.


Despite 50 years of research by many countries, including the United States, the the­oretical promise of the PBMR has not come to fruition. The technical problems encountered early on have yet to be resolved, or apparent­ly, even fully understood. PMBR proponents in the US have long pointed to the South African program as a model for the US. Ironically, the US Department of Energy is once again pursuing this design at the very moment that the South African government has pulled the plug on the program due to escalating costs and problems.

Other issues that will affect safety are NRC requirements for operating and security personnel, which have yet to be determined. To reduce operating costs, some SMR vendors are advocating lowering the number of staff in the control room so that one operator would be responsible for three modules. In addition, the SMR designers and potential op­erators are proposing to reduce the number of security staff, as well as the area that must be protected. NRC staff is looking to design­ers to incorporate security into the SMR de­signs, but this has yet to be done. Ultimately, reducing staff raises serious questions about whether there would be sufficient personnel to respond adequately to an accident.

Of the various types of proposed SMRs, liq­uid metal fast reactor designs pose particular safety concerns. Sodium leaks and fires have been a central problem — sodium explodes on contact with water and burns on contact with air. Sodium-potassium coolant, while it has the advantage of a lower melting point than sodium, presents even greater safety issues, because it is even more flammable than molten sodium alone. Sodium-cooled fast reactors have shown essentially no posi­tive learning curve (i.e., experience has not made them more reliable, safer, or cheaper).

The world’s first nuclear reactor to generate electricity, the EBR I in Idaho, was a sodium-potassium-cooled reactor that suffered a partial meltdown. EBR II, which was sodium-cooled reactor, operated reasonably well, but the first US commercial prototype, Fermi I in Michigan had a meltdown of two fuel assem­blies and, after four years of repair, a sodium explosion. The most recent commercial prototype, Monju in Japan, had a sodium fire 18 months after its commissioning in 1994, which resulted in it being shut down for over 14 years. The French Superphénix, the largest sodium-cooled reactor ever built, was designed to demonstrate commercialization. Instead, it operated at an average of less than 7 percent capacity factor over 14 years before being permanently shut.

In addition, the use of plutonium fuel or uranium enriched to levels as high as 20 percent — four to five times the typical enrichment level for present commercial light water reactors — presents serious proliferation risks, especially as some SMRs are proposed to be exported to developing countries with small grids and/or installed in remote locations. Security and safety will be more difficult to maintain in coun­tries with no or underdeveloped nuclear regulatory infrastructure and in isolated areas. Burying the reactor underground, as proposed for some designs, would not sufficiently address security because some access from above will still be needed and it could increase the environmental impact to groundwater, for example, in the event of an accident.

More complex waste problem
Proponents claim that with longer opera­tion on a single fuel charge and with less production of spent fuel per reactor, waste management would be simpler. In fact, spent fuel management for SMRs would be more complex, and therefore more expensive, because the waste would be located in many more sites. The infrastructure that we have for spent fuel management is geared toward light-water reactors at a limited number of sites. In some proposals, the reactor would be buried underground, making waste retrieval even more complicated and com­plicating retrieval of radioactive materials in the event of an accident. For instance, it is highly unlikely that a reactor contain­ing metallic sodium could be disposed of as a single entity, given the high reactivity of sodium with both air and water. Decom­missioning a sealed sodium- or potassium-cooled reactor could present far greater technical challenges and costs per kilowatt of capacity than faced by present-day above-ground reactors.

Not a climate solution
Efficiency and most renewable technologies are already cheaper than new large reactors. The long time — a decade or more — that it will take to certify SMRs will do little or noth­ing to help with the global warming problem and will actually complicate current efforts underway. For example, the current sched­ule for commercializing the above-ground sodium cooled reactor in Japan extends to 2050, making it irrelevant to addressing the climate problem. Relying on assurances that SMRs will be cheap is contrary to the experi­ence about economies of scale and is likely to waste time and money, while creating new safety and proliferation risks, as well as new waste disposal problems.

(This is a shortened version of the factsheet on Small Modular Reactors produced by Arjun Makhijani and Michelle Boyd for the Institute for Energy and Environmental Research (IEER) and Physicians for Social Responsibility (PSR), September 2010. It is available at:

Contact: Leslie Anderson, +1 703 276-3256

Institute for Energy and Environmental ResearchPSR