Small modular nuclear reactors: a history of failure

Dozens of ‘small modular reactor’ designs are being promoted but precious few will reach the construction stage and the likelihood of SMRs being built in large numbers is negligible.

Small modular reactors (SMRs) have been the subject of endless hype in recent years but in fact, no SMRs have ever been built, none are being built now and in all likelihood none will ever be built because of the prohibitive costs.

SMRs are defined as reactors with a capacity of 300 megawatts (MW) or less with serial factory production of reactor components (or ‘modules’). No SMRs have been built, but dozens of small (<300 MW) power reactors have been built in numerous countries, without factory production of reactor components.

Before looking at the troubled history of small reactors, it’s important to note the context for the explosion in SMR hype. The hype for new types of reactors is largely a result of the stunning failure of conventional reactor construction projects.

In the U.S., the only current reactor construction project is the Vogtle project in Georgia (two AP1000 reactors). The latest cost estimate of $34 billion is more than double the estimate when construction began – $14-15.5 billion.

The V.C. Summer project in South Carolina (two AP1000 reactors) was abandoned in 2017 after the expenditure of around $9 billion. U.S. nuclear giant Westinghouse filed for bankruptcy shortly after the abandonment of the South Carolina project, and its parent company Toshiba only survived by selling off its most profitable assets.

In 2006, Westinghouse said it could build an AP1000 reactor for as little as $1.4 billion, 12 times lower than the current estimate for Vogtle.

In the late 2000s, the estimated construction cost for one EPR reactor in the U.K. was £2 billion (US$2.52 billion). The current cost estimate for two EPR reactors under construction at Hinkley Point ‒ the only reactor construction project in the UK ‒ is up to £46 billion (US$58 billion). Thus the current cost estimate is 11.5 times greater than the initial estimate of £2 billion per reactor.

The only current reactor construction project in France is one EPR reactor under construction at Flamanville. The current cost estimate of €19.1 billion (US$20.8 billion) is nearly six times greater than the original estimate of €3.3 billion (US$3.58). (Lower figures cited by EDF and others typically exclude finance costs.)

The costs of reactors in the U.S., the U.K. and France range from $17 billion to $29 billion per reactor. The ballooning cost estimates have increased 12-fold, 11.5-fold and 6-fold, respectively.

Globally, nuclear power generation has been stagnant for 30 years. Nuclear power’s share of global electricity generation has nearly halved from 17.5% in 1996 to 9.2% now. Renewables have climbed to 30.2% and the International Energy Agency (IEA) expects renewables to reach 42% by 2028.

The global nuclear power renaissance never happened, partly because of the international fallout of the Fukushima disaster and partly because of the catastrophic cost overruns with conventional reactor projects.

It is in this context that the industry has pivoted to promoting SMRs. However, history suggests it is false hope.

The history of small reactors

The history of small reactors is a history of failure. The U.S. Army built and operated eight small reactors beginning in the 1950s, but they proved unreliable and expensive and the program was shut down in 1977. In addition, 17 small civilian reactors were built in the US in the 1950s and 1960s, but all have since shut down.

Twenty-six small Magnox reactors were built in the U.K. but all have shut down and no more will be built. The only operating Magnox is a mini-Magnox in North Korea: the design was made public at an Atoms for Peace conference and North Korea uses its 5 MW Magnox to produce plutonium for nuclear weapons.

India operates 14 small pressurized heavy water reactors, each with a capacity of about 200 MW. Professor M.V. Ramana noted in his 2012 book, “The Power of Promise: Examining Nuclear Energy in India,” that despite a standardized approach to designing, constructing and operating these reactors, many suffered cost overruns and lengthy delays. There are no plans to build more of these small reactors in India.

Elsewhere, the history of small reactors is just as underwhelming. This includes three small reactors in Canada (all shut down), six in France (all shut down) and four in Japan (all shut down).

Ramana concludes his history of small reactors with this downbeat assessment: “Without exception, small reactors cost too much for the little electricity they produce, the result of both their low output and their poor performance.”

Just two SMR plants are said to be operating – neither meeting the “modular” definition of serial factory production of reactor components. These so-called SMRs exhibit familiar problems of massive cost blowouts and multi-year delays.

The construction cost of Russia’s floating twin-reactor plant increased six-fold and the OECD’s Nuclear Energy Agency estimates that the electricity it produces costs $200 per megawatt-hour (MWh). The reactor is used to power fossil fuel mining operations in the Arctic.

The other operating SMR – loosely defined – is China’s demonstration twin-reactor high-temperature gas-cooled reactor (HTGR). The World Nuclear Association states that the cost of the demonstration HTGR was $6,000 per kilowatt, three times higher than early cost estimates and two to three times higher than the cost of China’s larger Hualong reactors per kilowatt.

NucNet reported in 2020 that China dropped plans to manufacture 20 HTGRs after levelised cost estimates rose to levels higher than conventional large reactors. Likewise, the World Nuclear Association states that plans for 18 additional HTGRs at the same site as the demonstration HTGR have been “dropped”. China’s demonstration HTGR demonstrates yet again that the economics of small reactors doesn’t stack up.

Three SMRs are under construction – again with the qualification that there’s nothing ‘modular’ about these projects.

Argentina’s CAREM reactor has been a disaster. Construction began in 2014 and the National Atomic Energy Commission now hopes to complete the reactor in 2027 ‒ nearly 50 years after the project was conceived. The cost estimate in 2021 was $750 million for a reactor with a capacity of just 32 MW. That’s a huge expense for a reactor with the capacity of a handful of large wind turbines.

In 2021, China began construction of a 125 MW pressurized water reactor. According to China National Nuclear Corporation, construction costs per kilowatt will be twice the cost of large reactors, and levelised costs will be 50% higher than large reactors.

Also in 2021, construction of the 300 MW demonstration lead-cooled BREST fast neutron reactor began in Russia. The cost estimate has more than doubled to 100 billion rubles (US$1.1 billion) and no doubt it will continue to climb.

NuScale Power

In 2012, the US Department of Energy (DOE) offered up to $452 million to cover “the engineering, design, certification and licensing costs for up to two U.S. SMR designs.” The two SMR designs that were selected by the DOE for funding were NuScale Power and Generation mPower.

NuScale recently abandoned its flagship project in Idaho. The company secured subsidies amounting to around $4 billion from the U.S. government comprising a $1.4 billion subsidy from the DOE and an estimated $30 per megawatt-hour (MWh) subsidy in the Inflation Reduction Act. Despite that government largesse, NuScale didn’t come close to securing sufficient funding to get the project off the ground.

NuScale’s most recent cost estimates were through the roof: $9.3 billion for a 462 MW plant comprising six 77 MW reactors. That equates to $20,100 per kilowatt and a levelised cost of $89 per MWh. Without the Inflation Reduction Act subsidy of $30/MWh, the figure would be $129 per MWh.

Incredibly, NuScale still hopes to build SMRs but the company is burning cash and facing the real threat of bankruptcy.

Generation mPower

Generation mPower ‒ a collaboration between Babcock & Wilcox and Bechtel ‒ was the other SMR design prioritized by the U.S. DOE. mPower was to be a 195 MW pressurized light water reactor.

In 2012, the DOE announced that it would subsidize mPower in a five-year cost-share agreement. The DOE’s contribution would be capped at $226 million, of which $111 million was subsequently paid. The following year, Babcock & Wilcox said it intended to sell a majority stake in the joint venture, but was unable to find a buyer.

In 2014, Babcock & Wilcox announced it was sharply reducing investment in mPower to $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.”

The mPower project was abandoned in 2017. The joint venture companies spent more than $375 million on the project, in addition to the DOE’s $111 million contribution.

The fallout from the NuScale and mPower failures

NuScale and mPower had everything going for them: large, experienced companies; conventional light-water reactor designs; and generous government subsidies. But they struggled to secure funding other than government subsidies.

Needless to say, non-government funding is even more difficult to secure for projects without the involvement of large companies; projects that envisage construction of unconventional reactors such as molten salt reactors, fast neutron reactors, etc.; and projects that haven’t secured generous government subsidies.

NuScale’s failure is particularly striking given the extent of the government subsidies and that NuScale had progressed further through the licensing process than other SMR designs – which isn’t saying much.

Other SMR failures

Many other plans to build small reactors have been abandoned. In 2013, American company Transatomic Power was promising that its “Waste-Annihilating Molten-Salt Reactor” would deliver safer nuclear power at half the price of power from conventional, large reactors. By the end of 2018, the company had given up on its “waste-annihilating” claims, run out of money and gone bust.

A study by Stanford and the University of British Columbia in 2022 showed that SMRs actually generate more radioactive waste than conventional nuclear power plants. 

MidAmerican Energy gave up on its plans for SMRs in Iowa in 2013 after failing to secure legislation that would require ratepayers to partially fund construction costs.

In 2018, TerraPower abandoned its plan for a prototype fast neutron reactor in China due to restrictions placed on nuclear trade with China by the Trump administration.

The French government abandoned the planned 100-200 MW ASTRID demonstration fast reactor in 2019.

The U.S. government abandoned consideration of ‘integral fast reactors‘ for plutonium disposition in 2015 and the U.K. government did the same in 2019. (Plutonium disposition means destroying weapons-usable plutonium through irradiation, or treating plutonium in such a way as to render it useless in nuclear weapons.)

“Advanced” nuclear power on the retreat

Dozens of SMR designs are being promoted worldwide ‒ mostly by start-ups with nothing more than a Powerpoint presentation. Precious few will reach the construction stage and the likelihood of SMRs being built in large numbers is negligible.

Likewise there are dim prospects for the broader ‘advanced’ or “Generation IV” nuclear sector, those comprising reactor concepts with a variety of different fuels, moderators or coolants.

A November article from the pro-nuclear Breakthrough Institute put the failure of NuScale’s Idaho project in context:

“The NuScale announcement follows several other setbacks for advanced reactors. Last month, X-Energy, another promising SMR company, announced that it was canceling plans to go public. This week, it was forced to lay off about 100 staff.

“In early 2022, Oklo’s first license application was summarily rejected by the Nuclear Regulatory Commission before the agency had even commenced a technical review of Oklo’s Aurora reactor.

“Meanwhile, forthcoming new cost estimates from TerraPower and XEnergy as part of the Department of Energy’s Advanced Reactor Deployment Program “are likely to reveal substantially higher cost estimates for the deployment of those new reactor technologies as well.”

The Breakthrough Institute notes that efforts to commercialize a new generation of advanced nuclear reactors “are simply not on track” and it warns nuclear advocates not to “whistle past this graveyard.”

Predictably, the Institute’s proposed solutions include vastly greater government subsidies and a weakening of safety standards and radiation protection standards.

The technical and extreme cost challenges of SMRs has been known and widely reported on for years, raising the question of why the hype continues to grow and, most importantly, why governments continue to subsidize this failed technology when investors rightly refuse to. 

More information on SMRs

• Friends of the Earth Australia: https://nuclear.foe.org.au/smr/

• WISE Nuclear Monitor 2019 report, https://wiseinternational.org/nuclear-monitor/872-873/nuclear-monitor-872-873-7-march-2019

• 'The 'advanced' nuclear power sector is fuelling climate change, and WMD proliferation', 11 Sept 2019, https://reneweconomy.com.au/the-advanced-nuclear-power-sector-is-fuelling-climate-change-and-wmds-40205/

• 'Nuclear power exits Australia's energy debate, enters culture wars', 13 June 2019, https://reneweconomy.com.au/nuclear-power-exits-australias-energy-debate-enters-culture-wars-47702/