Category Archives: Power Generating Technology – Nuclear

Remembering the Importance of the Boiling Reactor Experiments (BORAX) Conducted in Idaho in the 1950s & Early 1960s

Peter Lobner

Seventy years ago, the U.S. Atomic Energy Commission (AEC) conducted a series of tests at the National Reactor Testing Station (NRTS, now Idaho National Laboratory) with the Boiling Reactor Experiment (BORAX)-series of reactors. These small test reactors established the engineering foundation for commercial light water-cooled, boiling water reactors (BWRs), which are operating today in many nations around the world.

In June 2024, the American Nuclear Society (ANS) published a brief overview of the BORAX program and reported:

“Prior to 1952, it was thought that boiling in a light water reactor core would result in destructive instabilities. Samuel Untermeyer proposed that reactivity feedbacks from steam formation would instead help to stabilize the chain reaction, and so Argonne (National Laboratory) designed the BORAX series of reactors to investigate the concept.”

You can watch an AEC video on the BORAX-I experiments here. This 19-minute video is notable particularly because it shows BORAX-I operating open-loop (venting steam from the operating boiling water reactor to the atmosphere) and it shows the effects of a series of increasingly severe reactivity transient tests, the last of which was designed to be a destructive test of the BORAX-I reactor.

BORAX-I final test. Source: Argonne

The BORAX-I series of transient tests demonstrated that “the boiling water reactor concept was viable and could be developed into a workable power reactor.”

In addition to BORAX-I, there were four more test reactors in the BORAX-series. All are briefly described on the Argonne National Laboratory website here.

The next test reactor in the BORAX series, BORAX-II, initially operated open-loop. After a steam and power conversion system was added to enable closed-loop operation and up to 2 MWe electric power generation, it was renamed BORAX-III. The town of Arco, Idaho, became the first community in the Nation to receive its entire supply of electric power from a nuclear reactor on 17 July 1955, when BORAX-III was temporarily connected to the local grid.  ANL reported 500 kW was used to power the BORAX facility, 1000 kW was used to power the Central Facilities Area at NRTS, and 500 kW was available to power the city of Arco.

Arco commemorative sign. Source: Author photo

BORAX-IV was a closed-loop BWR that operated from 1956 to 1958 and was used primarily to test uranium and thorium oxide fuel and measure the impact of small fuel defects on radioactivity levels in steam plant equipment. ANL concluded, “On the basis of these experiments, it was predicted that a boiling reactor, fueled with ceramic fuel, can safely operate for long periods of time with many fuel cladding defects.”

The last test reactor in the series, BORAX-V, introduced an integral nuclear superheat system, which raised the saturated steam conditions exiting the core to high-pressure, dry steam conditions similar to a conventional (fossil-fueled) superheated steam power plant. This feature was used later in the 17.5 MWe BONUS (Boiling Nuclear Superheat) reactor, which was built under the AEC-sponsored Power Demonstration Reactor Program. BONUS was designed by General Nuclear Engineering Corp. and operated by the Puerto Rico Water Resources Authority from 1965 to 1968. You can watch a 1967 AEC video on the BONUS reactor here

The boiling nuclear superheat feature demonstrated in BORAX-V was used in one other Power Demonstration Reactor Program reactor, the 203 MWt Pathfinder, which operated from 1962 to 1968. However, this feature was not incorporated into later U.S. commercial BWR designs by General Electric.

The BORAX-series of test reactors was followed by the Experimental Boiling Water Reactor (EBWR), which was built in 1961 at Argonne National Laboratory in Illinois. EBWR was designed for steady-state power operation, initially at 20 MWt (5 MWe). Higher-power steady-state operations were conducted in the 20 to 40 MWt range, with short-term operation at up to 61.7 MWt (limited by feedwater pump capacity). Stable operation of EBWR at 100 MWt was expected to be possible. You’ll find an ANL video overview of the EBWR here.

EBWR. Source: Argonne flickr gallery

In its video, ANL reported, 

“Operations with EBWR proved that a direct cycle boiling water reactor system could operate, even at power levels five times its rated heat output, without serious radioactive contamination of the steam turbine. EBWR, sometimes referred to as CP-7, was operated until 1967. 

EBWR, operated with a largely plutonium core, provided valuable information on plutonium recycle operation of water reactors—it generated plutonium-based electricity for Argonne’s physical plant in 1966. 

When closed down the following year, EBWR had established a reputation as the forerunner of many commercial nuclear energy plants. One of those is the (General Electric-designed) Commonwealth Edison facility at Dresden, IL, which in 1960, became the first privately operated nuclear energy plant.”

You’ll find an overview and comparison of General Electric’s commercial BWR/1 to BWR/6 reactors in report NUREG/CR-5640, which is listed below.

For more information:





GE commercial BWRs

The NRC will allow the Diablo Canyon 1 & 2 nuclear power plants to continue operating while considering their belated license renewal applications

Peter Lobner

This is good news for all Californians and California businesses that depend on the State’s rather fragile electrical grid as their primary source of electric power! 

On 2 March 2023, the U.S. Nuclear Regulatory Commission (NRC) granted an exemption to Pacific Gas & Electric Co. (PG&E) that would allow the Diablo Canyon 1 & 2 nuclear power plants to continue operating while the NRC considers its license renewal application. The NRC press release stated:

“The exemption granted today will allow those licenses to remain in effect provided PG&E submits a sufficient license renewal application for the reactors by Dec. 31, 2023. The NRC will continue its normal inspection and oversight of the facility throughout the review to ensure continued safe operation. If granted, the license renewal would authorize continued operation for up to 20 years.”

Diablo Canyon Nuclear Power Plant. 
Source: Pacific Gas & Electric Company

You can read the full NRC press release here:

You can track the status of the Diablo Canyon license renewal process on the Nuclear Regulatory Commission website here:

You may recall that, in 2016, many environmental groups and state legislators claimed victory in getting the commitment from PG&E to close the Diablo Canyon nuclear power plant early.  Here’s just one example of that sentiment at the time:

“In a major victory for environmentalists, California is going nuclear-free, ending atomic energy’s more than half-century history in the state. On Tuesday, one of the state’s largest utilities agreed to a proposal endorsed by environmental groups and labor unions to shutter California’s last operating nuclear power plant, Diablo Canyon, by 2025.” (Source: Democracy Now, 22 June 2016).

In my 2016 post, “The Nuclear Renaissance is Over in the U.S.,” I noted: 

“On 21 June 2016, PGE issued a press release announcing that they will withdraw their application to the NRC for a 20-year license extension for the Diablo Canyon 1 & 2 nuclear power plants and will close these plants by 2025 when their current operating licenses expire.  PGE will walk away from about 41 GW-years of carbon-free electric power generation.”

Almost seven years ago, it was quite apparent to many that the early closure of Diablo Canyon would not be good for California or the environment.  It took that long for the state government to understand the situation and support the current effort to get the Diablo Canyon operating licenses extended.  Better late than never.  However, in their shortsighted view, the state government seems to be supporting a license extension only through 2030. If the legislators have their way, California will reclaim only a small portion of the carbon-free electric power generation that would be available from the 20 year operating license extensions that the NRC may grant.

I’d like see the California legislature and the associated complex web of state agencies that have a stake in this matter unanimously acknowledge that nuclear power is an important contributor toward energy de-carbonization.  In addition, I’d like to see that same group acknowledge that nuclear power plants are important for delivering reliable 24/7 generating capacity to the CALISO grid, and thereby helping maintain stability on a grid with a large fraction of variable-output, renewable generators.  If those factors are important to California’s government, then perhaps there is a future for nuclear power in the state, including the new generation of small, modular reactors (SMRs). California state support for nuclear power generation would open many exciting options for modernizing and decarbonizing electric power generation, transmission and distribution throughout the state, while ensuring that reliable electric power is available to all residents and business, many of which are seeking to decarbonize their activities by replacing their fossil fuel use with electricity that is available as needed, 24/7.

You can call that my California dream.

For more information:

DoD’s Project Pele microreactor is being developed by BWXT with a target for initial operation at a DoD facility in 2027

Peter Lobner

In 2016 the Defense Science Board (DSB) identified energy as a critical enabler of future military operations. The DoD’s Strategic Capabilities Office (SCO) launched Project Pele with the objective to design, build, and demonstrate a prototype mobile nuclear reactor to provide reliable and resilient electric power, while minimizing risk of nuclear proliferation, environmental damage, or harm to nearby personnel or populations. 

The Pele reactor will be the first electricity-generating Generation IV nuclear reactor built in the United States. Check out the DoD Office of the Under Secretary of Defense, Research and Engineering (OUSD(R&E)) website for the Project Pele Environmental Impact Statement (EIS) here:

In June 2022, Department of Defense (DoD) selected BWXT to produce a single prototype Pele mobile microreactor, which will be a Brayton-cycle high-temperature gas-cooled reactor (HTGR) capable of generating an electrical output of 1 MWe to 5 MWe. See the story in Power magazine here:

The Pele reactor will use High-Assay, Low-Enriched Uranium (HALEU, <20% enriched) fuel in the form of TRstructural ISOtropic (TRISO) coated fuel pellets (each about the size of a poppy seed). 

Cross-section of a TRISO particle, greatly magnified.
Source: DOE

The reactor will be assembled and initially operated at the Idaho National Laboratory (INL), under the safety oversight of the Department of Energy (DOE).  The Pele reactor is expected to be transportable by rail, truck or cargo aircraft.

Pele reactor modes of transportation. Source: GAO

There’s a good status update on Project Pele in a February 2023 article on the Energy Intelligence website, “Interview: Pentagon’s Jeff Waksman on Project Pele Microreactor,” at the following link:

For more information

Ulstein’s Nuclear-powered Thor and its All-electric Companion Vessel Are a Zero-Carbon Solution for Marine Tourism

Peter Lobner

1. Introduction

In June 2022, the Norwegian firm Ulstein ( announced their conceptual design of a Replenishment, Research and Rescue (3R) vessel named Thor that will be powered by a thorium molten salt reactor (MSR). This vessel can function as a seaborne mobile charging station for a small fleet of electrically-powered expedition / cruise ships that are designed to operate in environmentally sensitive areas such as the Arctic and Antarctic. Other environmentally sensitive areas include the West Norwegian Fjords, which are UNESCO World Heritage sites that will be closed in 2026 to all ships that are not zero-emission. In the future, similar regulations could be in place to protect other environmentally sensitive regions of the world, thereby reinforcing Ulstein’s business case behind Thor and its all-electric companion vessels.

Ulstein’s Thor MSR-powered vessel (left) and 
Sif electrically-powered expedition / cruise vessel (right). 
Source: Ulstein

2. The MSR-powered Thor charging station

Thor is a 149-meter (500-foot) long, zero-emission, nuclear-powered vessel that features Ulstein’s striking, backwards-sloping X-bow, which is claimed to result in a smoother ride, higher speed while using less energy, and less mechanical wear than a ship with a conventional bow. 

For its R3 mission, Thor would be outfitted with work boats, cranes, a helicopter landing pad, unmanned aerial vehicles (UAVs), unmanned surface vessels, firefighting equipment, rescue booms, a lecture hall and laboratories.

As a charging station, Thor would be sized to recharge four all-electric vessels simultaneously.

Thor.  Source: Ulstein

Thor also could serve as a floating power station, replacing diesel power barges in some developing countries or in some disaster areas while the local electric power infrastructure is being repaired.

Ulstein projects that an operational Thor vessel could be launched in “10 to 15 years.” However, the development and licensing of a marine MSR is on the critical path for that schedule.  

Thor, starboard side views.  Source, both graphics: Ulstein

3. The all-electric Sif expedition / cruise ship

Sif, named after the goddess who was Thor’s wife, is a design concept for a 100-meter (330-foot) long, all-electric, zero-emission expedition / cruise ship designed to operate with minimal impact in environmentally sensitive areas. The ship will be powered by a new generation of solid batteries that are expected to offer greater capacity and resistance to fire than lithium-ion batteries used commonly today.  It will be periodically recharged at sea by Thor.

The ship can accommodate 80 passengers and 80 crew. 

Sif, starboard side view.  Source, both graphics: Ulstein

4. A marine MSR power plant

The pressurized water reactor (PWR) is the predominant marine nuclear power plant in use today, primarily in military vessels, but also in Russian icebreakers and a floating nuclear power plant in the Russian Arctic. 

Ulstein reported that it has been exploring MSR technology because of its favorable operating and safety characteristics. For example, an MSR operates at atmospheric pressure (unlike a PWR) and passive features and systems maintain safety in an emergency. If the core overheats, the molten salt fuel/coolant mixture automatically drains out of the reactor and into a containment vessel where it safely solidifies and can be reused.  You’ll find a good overview of MSR technology here:

While a few experimental MSRs have operated in the past, no MSR has been subject to a commercial nuclear licensing review, even for a land-based application. Ulstein favors a thorium-fueled MSR. The thorium-uranium-233 fuel cycle introduces additional technical and nuclear licensing uncertainties because of the lack of operational and nuclear regulatory precedents.

Several firms are developing MSR concepts. However, the combination of a marine MSR and a thorium fuel cycle remains elusive. Two uranium-fueled marine MSR design concepts are described below.

Seaborg Technologies

The Danish firm Seaborg Technologies (, founded in 2014, is developing a compact MSR (CMSR) with a rating of about 250 MWt / 100 MWe for use in power barges (floating nuclear power plants) of their own design (see my 16 May 2021 post). The thermal-spectrum CMSR uses uranium-235 fuel in a molten proprietary salt, with a separate sodium hydroxide (NaOH) moderator.  

A Seaborg Technologies CMSR module could generate 100 MWe. Dump tank shown below reactor. Source: Seaborg via NEI (2022)

Seaborg’s development time line calls for a commercial CMSR prototype to be built in 2024, with commercial production of power barges beginning in 2026. 

Source: Seaborg (2022)

In April 2022, Seaborg and the Korean shipbuilding firm Samsung Heavy Industries signed a partnership agreement for manufacturing and selling turnkey CMSR power barges. 

On 10 June 2022, Seaborg was selected by the European Innovation Council to receive a significant (potentially up to €17.5 million) innovation grant to help accelerate their work on the CMSR.

CORE-POWER and the Southern Company consortium

The UK firm CORE-POWER Ltd. (, founded in 2018, began with a concept for a compact uranium-235 fueled, molten chloride salt reactor named the m-MSR for marine applications. This modular, inherently safe, 15 MWe micro-reactor system was designed as a zero-carbon replacement power source for the fossil-fueled power plants in many existing commercial marine vessels.  It also was intended for use as the original power source for new vessels, as proposed for the Earth 300 Eco-Yacht design concept unveiled by entrepreneur Aaron Olivera in April 2021 (see my 17 April 2021 post). The power output of a modular CORE-POWER m-MSR installation could be scaled to meet operational needs by adding reactor modules in compact arrangements suitable for shipboard installation. 

A set of six small, compact CORE-POWER m-MSR modules
could generate 90 MWe. Dump tank not shown. Source: CORE-POWER

In November 2020, CORE-POWER announced that it had joined an international consortium to develop MSRs. This team includes the US nuclear utility company Southern Company (, US small modular reactor developer TerraPower ( and nuclear technology company Orano USA ( In the consortium, TerraPower is responsible for the fast-spectrum Molten Chloride Fast Reactor (MCFR). CORE-POWER is responsible for maritime readiness and regulatory approvals.

This consortium applied to the US Department of Energy (DOE) to participate in cost-share risk reduction awards under the Advanced Reactor Demonstration Program (ARDP), to develop a prototype MCFR as a proof-of-concept for a medium-scale commercial-grade reactor. In December 2020, the consortium was awarded $90.4 million, with the goal of demonstrating the first MCFR in 2024.  DOE reported, “They expect to begin testing in a $20 million integrated effects test facility starting in 2022. The team has successfully scaled up the salt manufacturing process to enable immediate testing. Data generated from the test facility will be used to validate thermal hydraulics and safety analysis codes for licensing of the reactor.”In February 2021, CORE-POWER presented the MCFR development schedule in the following chart, which shows the MCFR becoming available for deployment in marine propulsion in about 2035.  This is within the 10 to 15 year timescale projected by Ulstein for their first Thor vessel.

Source: CORE-POWER (2021)

5. In conclusion

A seaborne nuclear-powered “charging station” supporting a small fleet of all-electric marine vessels provides a zero-carbon solution for operating in protected, environmentally sensitive areas that otherwise would be off limits to visitors. Ulstein’s concept for the MSR-powered Thor R3 vessel and the Sif companion vessel is a clever approach for implementing that strategy.

It appears that a uranium-fueled marine MSR could be commercially available in the 10 to 15 year time frame Ulstein projects for deploying Thor and Sif.  The technical and nuclear regulatory uncertainties associated with a thorium-fueled marine MSR will require a considerably longer time frame. 

6. For additional information 

Ulstein Thor & Sif


Seaborg CMSR


Could Nuclear-Powered Crypto Currency Mining Become a Trend?

Peter Lobner, updated 8 March 2024

The term “bitcoin mining” has become a colloquial expression, but the actual activity involved in mining a crypto currency isn’t intuitively obvious to the casual observer. Marcus Lu, reporting for Visual Capitalist, can help us out here.  He explained:

“When people mine bitcoins, what they’re really doing is updating the ledger of Bitcoin transactions, also known as the blockchain. This requires them to solve numerical puzzles which have a 64-digit hexadecimal solution known as a hash. Miners may be rewarded with bitcoins, but only if they arrive at the solution before others. It is for this reason that Bitcoin mining facilities—warehouses filled with computers—have been popping up around the world. These facilities enable miners to scale up their hashrate, also known as the number of hashes produced each second. A higher hashrate requires greater amounts of electricity, and in some cases can even overload local infrastructure.”

So your basic crypto currency miner needs a lot of computer processing power, electric power and an internet service provider.  To get started, all of that requires some hard currency, unless you can find a work-around. Now, a few recent headlines make a bit more sense:

  • “1,069 Bitcoin Miners Steamrolled In Malaysia for Stealing Energy,” 17 July 2021
  • “Illegal Crypto Mining Farm With Almost 5,000 Computers Busted in Ukraine – The illegal operation cost between $186,000 and $259,300 in electricity to the state each month.” 12 July 2021
  • “Police find bitcoin mine using stolen electricity in West Midlands (UK),” 28 May 2021
  • “U.S. small towns take on energy-guzzling bitcoin miners,” 13 May 2021
  • “Cryptocurrency miners grapple with major energy crunch in Kazakhstan,” 27 November 2021

These headlines suggest that crypto currency mining can generate significant wealth, and, for some, this prospect is worth the risk of being caught stealing a lot of electricity.  

Sam Ling, writing for Miner Daily in May 2021, describes his methodology for estimating the cost to mine a bitcoin, which depends on many factors, including the cost of electricity and the cost, processing power and lifetime of the computers.  Ling estimates: “It currently costs between $7,000-$11,000 USD to mine a bitcoin. …… As the price of BTC is $56,000, it remains very profitable to mine bitcoin.” You’ll find more details here:

Of course, there are many legitimate businesses mining bitcoins.  You’ll find a list of the top bitcoin mining firms here:

At the industrial-size end of the crypto mining facility spectrum, US power company Talen Energy announced in July 2021 that it is planning to develop a nuclear-powered crypto mining facility and data center adjacent to its two unit, 2,494 MWe Susquehanna Steam Electric Station in Pennsylvania. The first phase of the crypto mining facility will require 164 MW of power and is due to come online in Q2 2022. When complete, the crypto mining facility will require 300 MW of on-site power supplied from the nuclear power plants via two independent substations.  The potential exists to expand the crypto mining facility to 1,000 MW capacity in the future.

The planned Talen Energy crypto mining facility at the Susquehanna Steam Electric Station.  Source: DataCenterDynamics via Interesting Engineering

In May 2021, Nic Carter reported in the Harvard Business Review, “According to the Cambridge Center for Alternative Finance (CCAF), Bitcoin currently consumes around 110 Terawatt-Hours per year — 0.55% of global electricity production, or roughly equivalent to the annual energy draw of small countries like Malaysia or Sweden.”  That would put current global crypto currency mining energy consumption at about 30th place among all nations in the world.  In the future, energy consumption for crypto currency mining is certain to increase, perhaps dramatically.  Is there an upper limit?

The current trend in tracked by Digiconomist with their Bitcoin Energy Consumption Index, which provides the latest estimate of the total energy consumption of the Bitcoin network. The following chart is from their website here:

While the Susquehanna Steam Electric Station is fortunate to have a gained a new customer for their electric power, Exelon Generation reported in June 2021 that three of its Illinois nuclear power plants, Byron, Dresden, and Quad Cities, did not clear the PJM Interconnection capacity auction. This means that these Exelon nuclear plants have lost a customer for their future electric power generation. The issue is complex, but appears to be rooted in power auction rules that are, at least in part, inconsistent with the nation’s goal of reducing the overall carbon footprint of electric power generation. Exelon explained:

“Byron and Dresden, despite being efficient and reliable units, face revenue shortfalls in the hundreds of millions of dollars because of declining energy prices and market rules that allow fossil fuel plants to underbid clean resources in the PJM Interconnection capacity auction.”

In mid-September 2021, Illinois Gov. J.B. Pritzker signed an energy bill (Senate Bill 2408) that included provisions for Exelon to receive the financial incentives it needed to keep the Byron and Dresden nuclear plants open.  Exelon subsequently confirmed that the plants will continue operating for at least six more years (thru 2027).

Exelon is not the only US nuclear power utility with this type of issue. Several more US nuclear power plants are at risk of retiring prematurely instead of seeking a license extension to operate for another 20 years generating zero-carbon electricity.  S&P Global Platts provides a good overview of the seriousness of the current situation in the following infographic:

Source: S&P Global Platts, 3 May 2021

Congress and the state governments need to act now to protect the nuclear power plants at high risk of premature closure, and ensure their continued operation as generators of zero-carbon electricity.

Perhaps the planned Talen Energy crypto currency mining venture points to an odd synergism between miners and nuclear power plant operators. Instead of retiring nuclear power plants that are struggling financially, it may make sense to the owners to build crypto mining facilities and reap the profits from crypto currency sales. Taken to its extreme, you can imagine a nuclear power plant diverting all of its zero-carbon electric power output to its own very profitable crypto mining facility. Just imagine how many Bitcoins could be generated by diverting all US nuclear power plant electricity generation (about 20% of total US electricity generation) to power crypto currency miners. 

Going back to my question “Is there an upper limit?,” I’m afraid only time will tell.  

8 March 2024 update: Talen Energy data center sold

The completed Talen Energy data center building at the Susquehanna nuclear plant. Source: Talen Energy

Talen Energy’s bitcoin mining adventure was not successful. In May 2022, the firm filed for Chapter 11 bankruptcy in connection with a financial restructuring of the firm. After exiting bankruptcy in 2023, the firm sought to sell its Susquehanna data center as a means to pay off debts and generally improve its cash flow. On 4 March 2024, Talen Energy announced the sale of its Susquehanna data center campus for $650 million to cloud service provider Amazon Web Services (AWS). By virtue of its existing Power Purchase Agreement (PPA) with Susquehanna, Talen Energy remains as an energy retailer, positioned between the Susquehanna nuclear power plant and the AWS-owned data center. Talen will providing fixed-price electricity to the AWS data center, which has a contractual commitment to ramp up its power demand as the data center is expanded over several years. AWS has a one-time option to cap its power demand at 480 MW. Talen will be able to supply up to 960 MW of power under the terms of its PPA with Susquehanna. 

For more information

Nuclear power plants at risk of closure

Bitcoin miner energy theft & adverse impacts on electrical grids

Floating Nuclear Power Plants Will be Operating at Several Sites Around the World by the End of the 2020s

Peter Lobner

1. Introduction

This post is an update and supplement to the information on floating nuclear power plants (FNPPs) in my July 2018 post, “Marine Nuclear Power: 1939 – 2018,” at the following link:

An FNPP is a transportable barge housing one or more nuclear power reactors that can deliver electric power and other services, such as low temperature process heat and/or desalinated water, to users at a wide variety of coastal or offshore sites. FNPPs are a zero-carbon energy solution that has particular value in remote locations where the lack of adequate electrical power and other basic services are factors limiting development and/or the quality of life.

After being manufactured in a shipyard, the completed FNPP is fueled, tested and then towed to the selected site, where a safe mooring provides the interfaces to connect to the local / regional electrical grid and other user facilities.

The US operated the first FNPP, Sturgis, in the Panama Canal from 1968 to 1975.  Sturgiswas equipped with a 45 MWt / 10 MWe Martin Marietta MH-1A pressurized water reactor (PWR) that was developed under the Army Nuclear Power Program. 

Sturgis moored in the Panama Canal. Source: Army Corps of Engg’s

Sturgis supplied electric power to the Panama Canal Zone grid, replacing the output of Gatun Hydroelectric Plant. This allowed more water from Gatun Lake to be available to fill canal locks, enabling 2,500 more ships per year to pass through the canal. After decommissioning, dismantling was finally completed in 2019.

2. Akademik Lomonosov – The first modern FNPP

It wasn’t until 2019 that another FNPP, Russia’s Akademik Lomonosov, supplied power to a terrestrial electricity grid, 44 years after Sturgis.  The Lomonosov is a one-of-a-kind, modern FNPP designed for operation in the Arctic.  With two KLT-40S PWRs, Lomonosov supplies up to 70 MWe of electric power to the isolated Chukotka regional power grid or up to 50 Gcal/h of low temperature process heat at reduced electrical output to users in the industrial city of Pevek, near the eastern end of Russia’s Northern Sea Route. 

Akademik Lomonosov at Pevek. Source: Sputnik / Pavel Lvov

Lomonosov started providing electricity to the grid on 19 December 2019 and regular commercial operation began on 22 May 2020.

3. FNPPs under development by several nations

Several nations are developing new FNPP designs along with plans for their serial production for domestic and/or export sale.  The leading contenders are presented in the following chart. 

Floating Nuclear Power Plants in Operation & Under Development

Akademik Lomonosov and the first four new FNPP designs in the above chart use small PWRs in various compact configurations. PWRs have been the dominant type of power reactor worldwide since their introduction in naval reactors and commercial power reactors in the 1950s. The Seaborg power barges will use compact molten salt reactors (CMSRs) that have functional similarities to the Molten Salt Reactor Experiment (MSRE) that was tested in the US in the early 1960s.


Russia is developing their 2nd-generation “optimized floating power unit” (OPEB) to deliver 100 MWe electric power, low temperature process heat and water desalination to support their domestic economic development in the Arctic. In November 2020, Rosatom director for development and international business, Kirill Komarov, reported that there was demand for FNPPs along the entire length of Russia’s Northern Sea Route, where a large number of projects are being planned. This was reinforced in May 2021, when Russia’s President Vladimir Putin endorsed a plan to deploy OPEBs to supply a new power line at Cape Nagloynyn, Chaunskaya Bay, to support the development of the Baimskaya copper project in Chukotka.  The development plan calls for 350 MWe of new generation from nuclear or liquid natural gas (LNG) generators.  Baimskaya currently is supplied from Pevek, where the Lomonosov is based.

Chaunskaya Bay & Pevek in Russia’s Arctic Far East. Source:  Google maps

A version of the OPEB also is intended for international export and has been designed with the flexibility to operate in hot regions of the world.  Bellona reported that “Rosatom has long claimed that unspecified governments in North Africa, the Middle East and Southeast Asia are interested in acquiring floating nuclear plants.”


In the 1960s, China Shipbuilding Industry Corporation (CSIC) set up the 719 Research Institute, also known as the Wuhan Second Ship Design Institute or CSIC 719, to develop applications for nuclear power technology in marine platforms. CSIC has become China’s biggest constructor of naval vessels, including nuclear submarines. 

About a decade ago, China considered importing FNPP technology from Russia.  In 2015, China’s National Development and Reform Commission (NDRC) agreed with a CSIC 719 design plan to develop an indigenous offshore marine nuclear power platform. This plan included both floating nuclear power plants and seabed-sited nuclear power plants. Today, part of this plan is being realized in the FNPP programs at China National Nuclear Corporation (CNNC) and China General Nuclear Power (CGN), two staunch competitors in China’s nuclear power business sector.

China included the development of CNNC’s 125 MWe ACP100S and CGN’s 65 MWe ACPR50S marine PWR plants in its 13th five-year plan for 2016 to 2020. The NDRC subsequently approved both marine reactor designs. 

As an example of the magnitude of China’s domestic offshore market for FNPPs, the total installed fossil fuel-powered generation in China’s offshore Bohai oilfield was estimated to be about 1,000 MWe in 2020 and growing.  Replacing just these generators and providing heating and desalination services for offshore facilities represents a near-term market for a dozen or more FNPPs.  Other domestic application include providing these same services at remote coastal sites and offshore islands. China has announced its intention to construct a batch 20 FNPPs for domestic use. The Nuclear Power Institute of China (NPIC) has recommended installing the country’s first FNPP at a coastal site on the Yellow Sea near Yantai, Shandong Province. South Korea raised its objection to this siting plan in 2019.  

Possible site for China’s first FNPP.
Source: Pulse (22 Mar 2019)

Other possible FNPP deployment sites may include contested islands that China has begun developing the South China Sea.  This is a very sensitive political issue that may partially account for why there has been very little recent news on the CNNC and CGN FNPP programs.  Based on their development plans discussed about five years ago, it seemed that China’s first FNPP would be completed in the early 2020s. 

In addition to their domestic applications, China has repeatedly expressed interest in selling their FNPPs to international customers.

South Korea & Denmark

In the absence of clear domestic FNPP markets in South Korea and Denmark, KEPCO E&C and Seaborg Technologies are focusing on the export market, primarily with developing nations.  

Details on modern FNPP designs 

You’ll find more details on these new FNPPs in my separate articles at the following links:

4. Maintaining FNPP fleets

All of the new FNPPs require regular reactor refueling and periodic maintenance overhauls during their long service lives.  The periodic overhauls ensure that the marine vessel, the reactor systems and ship’s systems remain in good condition for their planned service life, which could be 60 or more years.

The FNPPs with PWRs have refueling intervals ranging from about 2 years (ACP100S) to as long as 10 years (RITM-200). Some of the PWR refuelings will be conducted dockside, while others will be conducted in a shipyard during a periodic maintenance overhaul. For Russian FNPPs, such overhauls (referred to as “factory repairs”) are scheduled to occur at 12-year intervals for the Lomonosov and 20-year intervals for the OPEB.

The fundamentally different Seaborg CMSR, with molten salt fuel, is refueled regularly while the reactor is operating.  Periodic maintenance overhauls would still be expected to ensure the condition of the marine vessel, the reactor systems and ship’s systems.

With a fleet of FNPPs in service, most will be operating, while some are in the shipyard for their periodic maintenance overhauls.  In addition, new FNPPs would be entering service periodically. When it is time to service an FNPP in a shipyard, it will be replaced by a different (existing or new) FNPP that is brought in to take its place.

At the end of its service life, an FNPP will be returned to a shipyard to be decommissioned, decontaminated and then dismantled, like Sturgis. Russia already has established special long-term spent fuel and radioactive waste storage facilities in mainland Russia. China, South Korea and Denmark will need to make similar provisions for the end-of-life processing and safe disposition of their retired FNPPs.

5. Economic issues

In March 2019, Jim Green wrote on what he called “the questionable economics of SMRs” in his article, “An obituary for small modular reactors.” One of his conclusions was that, “…in truth there is no market for SMRs.”  Another conclusion was that “No-one wants to pay for SMRs. No company, utility, consortium or national government is seriously considering building the massive supply chain that is at the very essence of the concept of SMRs ‒ mass, modular factory construction. Yet without that supply chain, SMRs will be expensive curiosities.” 

I might agree that this could be the case for land-based SMRs, but marine FNPPs are a different matter.  In remote areas being considered for FNPP deployment, there probably are fewer energy options, energy price competition is a lesser concern, and an extended fuel supply chain is undesirable or impractical. Examples include FNPP applications supporting resource development along Russia’s Northern Sea Route and in China’s offshore waters.  The domestic markets in both nations probably can support production runs of 10s of FNPPs.  While this isn’t “mass production” in the sense of many heavy industries, it would certainly be a big enough production run to change the manufacturing paradigm in the marine nuclear industry and provide a real validation of the economics of SMRs.

6. International nuclear regulatory / legal / political issues

Deployment of the first modern FNPP, the Akademik Lomonosov, in the Arctic was accomplished under Russian domestic nuclear laws and regulations and, after the reactors were fueled, the transit to its destination was accomplished within Russian territorial waters. The final destination, Pevek, is about 980 km (609 miles) from the Bering Strait and the nearest international boundary.  Not without controversy, particularly among Scandinavian nations, Lomonosov’s deployment was straightforward after the vessel completed all stages of licensing and regulatory reviews required in Russia.  Now Lomonosov has been commissioned and is setting an example for the rest of the world by operating successfully in a remote Arctic port.

Except for Russia’s nuclear-powered icebreaking vessels, there have been no other civilian nuclear vessels in service since Japan’s Mutsu retired in 1992. For almost 30 years, there has been no need to establish and maintain a comprehensive international civilian nuclear vessel regulatory and legal framework. 

In her August 2020 article, “Legal framework for nuclear ships,” Iris Bjelica Vlajić reports that the main international documents regulating the use of civil nuclear ships are:

  • UN Convention on the Law of the Sea (UNCLOS)
  • IMO Convention for the Safety of Life at Sea (SOLAS)
  • IMO Convention on The Liability of Operators of Nuclear Ships and the Code of Safety for Nuclear Merchant Ships

Further FNPP deployment along Russia’s arctic coast and initial FNPP deployment in China’s territorial coastal waters can be accomplished under the respective nation’s domestic nuclear laws and regulations.  It’s easy to imagine that a range of international issues will arise as FNPP deployment becomes more widespread, in situations like the following

  • An FNPP is deployed to a site close to an international border.
  • An FNPP is deployed in a sensitive international ecosystem.
  • A fueled FNPP from any nation needs to transit an international strait or an exclusive economic zone (EEZ) of another nation enroute to its destination.
  • An FNPP is deployed to an island that is contested by one or more other nations (i.e., several islands and island groups in the South China Sea).

There has been speculation recently that the sensitivity of the last issue, above, may be contributing to increased secrecy in the last couple of years related to China’s FNPP programs.

As FNPP deployment expands, the international community will be playing catch-up as the UN, IMO, IAEA and others contribute to developing a modern nuclear regulatory and legal framework for FNPPs.

7. Conclusions

In the next decade, I think it’s very likely that two or more of the new FNPP designs will enter service.  The leading contenders seem to be Russia’s OPEB and China’s ACP100S FNPP.   It remains to be seen if economic issues and/or international nuclear regulatory / legal / political issues will stand in the way of eventual FNPP deployments to sites around the world.  

8. For more information


US – Sturgis



South Korea

Denmark – Seaborg


Other FNPP designs and concepts for “transportable reactor units” (only the nuclear steam supply section of an FNPP) and seabed-sited nuclear power plants are included in my 2018 post: “Marine Nuclear Power: 1939 – 2018:”

The Sad Tale of New York’s “Greener Grid” and the Closure of Two Nuclear Power Plants

Peter Lobner, updated 29 July 2022

Goodbye Indian Point 2 and 3.  Your contributions of zero-carbon energy to New York’s “clean energy grid of the future” will be greatly missed.

In an average year, the 1,028-MWe Indian Point Unit 2 nuclear power plant and the 1,041-MWe Unit 3 operated at capacity factors of greater than 90% and delivered more than 18,000 GWh (thousand MWh) per year of zero-carbon electricity to the New York state electrical grid. Unit 2 was shutdown on 30 April 2020 and Unit 3 followed on 30 April 2021.  Prior to its final shutdown, Unit 3 had run continuously for 753 day, which set a new nuclear industry world record.  The ANS Newswire reported, “The plant’s closure is the result of a settlement agreement reached in 2017 by Entergy and the State of New York and environmental groups opposed to Indian Point’s operation. According to an April 28 (2021) news release from Entergy, its decision to accede to the shutdown was driven by a number of factors, including ‘sustained low current and projected wholesale energy prices that reduced revenues.’”

Now, Indian Point Units 2 and 3 are delivering exactly zero zero-carbon energy.  I imagine the environmental groups involved in the settlement agreement are hailing the shutdowns as great achievements.  I think the shutdowns represent remarkable shortsightedness (I’m using the kindest words I can think of) on the parts of Entergy and the State of New York.

New York Independent System Operator, Inc. (NYISO) operates the New York state electrical grid, which is divided into two main parts, “downstate”, which includes New York City and the Indian Point Units 2 and 3 nuclear power plants, and “upstate,” which includes the Nine Mile Point and Ginna nuclear power plants. I credit NYISO with providing the public with excellent reports that summarize their annual grid and electrical market performance.  In their Power Trends 2021 report, NYISO states: “The NYISO is committed to offering the tools, skills, independent perspectives, and experience necessary to transition to a zero-emission power system by 2040.” 

I’ll refer to two of those NYISO Power Trend reports to illustrate the impact of closing the Indian Point 2 and 3 nuclear power plants on progress toward New York’s “clean energy grid of the future.”  Using their own graphics, let’s take a look at how NYISO was doing in 2019 (with both Indian Point Unit 2 & 3 operating), 2020 (Unit 2 shutdown in April), and their projected performance in summer 2021 (after Unit 3 shutdown). 

2019:  New York statewide: 58% zero-emission; Upstate: 88% zero-emission; Downstate: 29% zero-emission

Source: NYISO Power Trends 2020

2020:  New York statewide: 55% zero-emission; Upstate: 90% zero-emission; Downstate: 21% zero-emission

Source: NYISO Power Trends 2021

2021:  New York statewide (projected, summer): 25% zero-emission; Upstate: 67% zero-emission; Downstate: 2% zero-emission

Source: NYISO Power Trends 2021

Anyone who can draw a tend chart from 2019 to 2021 using the above three years of data and then extrapolate to the State’s goal of a zero-emission power system by 2040 can see that New York’s plans for its “clean energy grid of the future” have come off the rails.  The slope of the curve to get from where NYISO is today to the State’s 2040 goal has gotten a lot steeper, and that translates directly into the cost of achieving that goal.  Surely the New York ratepayers served by NYISO will pay the price in the years ahead as the State works to improve its zero-emission performance. Even getting back to where they were in 2019 would be a big improvement.

So, I reiterate that the Indian Point Unit 2 and 3 shutdowns represent remarkable shortsightedness on the parts of Entergy and the State of New York, both of which have undervalued two reliable sources of bulk zero-emission electric power generation, and have failed to appreciate Indian Point’s potential long-term contribution to achieving the State’s 2040 zero-emission power system goal (at a rate of more than 18,000 GWh per year).  New York State has failed to step up and provide economic incentives to enable Entergy to compete effectively against fossil fuel generators that have been benefiting for more than a decade from the low cost of natural gas fuel. In the wholesale market, the fossil generators can undercut nuclear generators and drive the cost of electricity down to levels that no longer support the continued operation of zero-emission nuclear power plants.  These trends can be seen in the following NYISO chart.

Source: NYISO Power Trends 2021

Beyond the significant loss of zero-carbon electrical generation capacity, the closure of a nuclear power plant will have significant local and statewide impacts through the loss of many full-time and temporary jobs, associated wages, and income and property taxes.  You’ll find a thorough discussion of these issues in the May 2021 ANS Nuclear Newswire article, “The consequences of closure: The local cost of shutting down a nuclear power plant,” at the following link:

R.I.P. Indian Point Units 2 and 3.

Update – 29 July 2022

In July 2022, the American Nuclear Society reported, “Stats show that closing Indian Point was a ‘mistake’ for New York.”  I’d say that’s putting it mildly.

For more information:

Many European Union (EU) “Green Deal” Energy Advocates are Hypocrites

Updated 16 December 2019, 20 March & 5 May 2020

Peter Lobner

In a 12 December 2019 NUCNET article, David Dalton, reporting on the United Nations Framework Convention on Climate Change (COP25) in Madrid, summarized the following points made by International Atomic Energy Agency (IAEA) director-general Rafael Mariano Grossi:

  • The world is “well off the mark” from reaching the climate goals of the Paris Agreement.
  • Around two-thirds of the world’s electricity still is generated through burning fossil fuels.
  • Greater use of low-carbon nuclear power is needed to ensure the global transition to clean energy includes a baseload backup to variable renewable energy sources such as solar and wind.
  • Greater deployment of a diverse mix of low-carbon sources such as hydro, wind and solar, as well as nuclear power, and battery storage, will be needed to reverse that trend and set the world on track to meet climate goals.

I concur with these points and feel that Mr. Grossi has laid out a reasonable and responsible position on the future role of nuclear power in “green” energy solutions that are focused on the primary goal of  reducing worldwide carbon dioxide emissions.  The commercial nuclear power industry has demonstrated the ability to reliably generate carbon-free electricity, 24 hours a day, seven days a week, in units of a thousand megawatts or more per power plant.  Except for the largest hydroelectric facilities, no other component of a carbon-neutral energy infrastructure offers such capabilities, which are essential for delivering 24/7 service to large users and stabilizing the grid.  Unfortunately, Mr. Grossi’s view is not shared by many EU energy advocates seeking to get member states to agree to the EU “Green Deal.”

You can read David Dalton’s complete article here:

The EU Energy Union and the “Green Deal”

The European Energy Union is the implementation of the 2019 Juncker Commission’s Priority #3 recommendation for a resilient energy union with a forward-looking climate change policy.  You can read a summary of the Commission’s recommendations here:

The Energy Union has quite a challenge, starting with the EU’s energy mix (circa 2016) as shown in the following chart:

EU 2016 energy mix.  Source:  EU Statistical Pocketbook 2018

Complicating matters, the EU currently imports nearly 40% of its natural gas from Russia. 

The European Union’s Green Deal is described as “a new growth strategy that aims to transform the EU into a fair and prosperous society, with a modern, resource-efficient and competitive economy where there are no net emissions of greenhouse gases in 2050 and where economic growth is decoupled from resource use.”  You’ll find the EU’s 11 December 2019 detailed description of the Green Deal here:

For more information, see the EU “Green Deal” website here:

To enforce this “Green Deal,” the EU intends to adopt a “climate law” that is scheduled to be presented to Member States in March 2020.

The EU’s “Green Deal” is strongly biased against almost anything except renewable energy sources

On 11 December 2019, Reuters reported that, “European Union states have blocked a set of new rules governing which financial products can be called ‘green’ and ‘sustainable’, EU officials said, in a major setback for the bloc’s climate ambitions.”  The Reuters report noted that EU lawmakers wanted nuclear and fossil fuel funding clearly excluded from the definition of “green” investments. You can read this Reuters report here:

This EU position is a particular problem for France, where nuclear power provided 71.7% of total French generating capacity in 2018 and about 90% of total electrical capacity was provided by low-carbon sources (nuclear + renewables).  In October 2019, Électricité de France announced that it is planning to make a decision in 2021 on building several more large nuclear power plants, which will be needed in the next decade as its oldest 900 MWe pressurized water reactor (PWR) plants start reaching their retirement age.

In contrast, nuclear power provided 11.8% of total German generating capacity in 2018 and about 47% of total electrical capacity was provided by low-carbon sources (nuclear + renewables), while 48.3% of total generating capacity was provided by a fossil fuel sources.  Germany plans to decommission the last of its seven remaining nuclear power plants, representing an aggregate of 9,256 MWe of carbon-free electric generating capacity, in the next three years, by December 2022.  It will be a challenge for new renewable energy sources to be deployed in time to make up for the lost carbon-free generating capacity from nuclear power.  It is notable that Germany gets 7% of its total generating capacity from burning biomass, which the EU, in its great wisdom, defines as a carbon-neutral renewable energy source.  More on that later.

How does the EU define “clean energy”?

The EU’s definition of “clean energy” is rather elusive.  On the EU Green Deal website, the Clean Energy fact sheet identifies the following three “key principle:” 

  • Prioritize energy efficiency and develop a power sector based largely on renewable sources
  • Secure and affordable EU energy supply
  • Fully integrated, interconnected and digitalized EU energy market

Only “renewable sources” are actually defined as sources for “clean energy.”  Nuclear power is not identified as a “clean” energy source.  I was unable to find on the EU Green Deal website any performance metrics related to “clean” energy source performance relative to carbon emissions.

Here’s the link to the EU Clean Energy Fact Sheet:

Another EU description of “clean energy” can be found the “Clean Energy for all Europeans” program, which focuses on the following:

  • Energy efficiency first, focusing on energy saving opportunities and “smarter” / “greener” buildings.
  • More renewables, with a new target of at least 32% in renewable energy by 2030
  • Better governance of the Energy Union, including a new energy “rulebook” under which each EU Member State drafts a National Energy and Climate Plan (NECP)
  • More rights for consumers to produce, store or sell their own energy
  • Smarter and more efficient electricity market

The Clean Energy for all Europeans program is described here:

The focus is on a distributed electric power infrastructure that takes advantage of many ways to improve energy efficiency, manage power consumption and generate power from distributed renewable energy sources.  Nuclear power is not mentioned at all in this document.  However, “large scale biopower” from agricultural and forest sources is addressed. 

How does the EU define “renewable energy sources”?

The latest EU directive on the promotion of energy use from renewable sources is Directive (EU) 2018/2001, dated 11 December 2018.  The definition of “renewable energy sources” traces back to Directive 2003/54/EC, dated 26 June 2003:

“Renewable energy sources” means renewable non-fossil energy sources (wind, solar, geothermal, wave, tidal, hydropower, biomass, landfill gas, sewage treatment plant gas and biogases)

So, fossil energy sources are excluded and nuclear energy sources are not included.

This seems logical but the devil is in the details.  The main problem is that EU energy policy equates “renewable” with being “carbon free,” when, for some renewable energy sources, this is far from the truth.  As an example, existing EU policy treats burning wood fuel in power plants as carbon-neutral while this fuel generates 15 to 20% more carbon dioxide per megawatt than the coal fuel it replaces.  This has resulted in a trend among EU coal-burning power plants to switch to wood pellets and claim the emission credit while actually polluting more than before.  See my 7 January 2017 post, “Hey, EU!! Wood may be a Renewable Energy Source, but it isn’t a Clean Energy Source,” for details.  The direct link to this post is here:

Fortunately, this matter may be on its way to being addressed in an EU court.  A 4 March 2019 article by Karen Savage, writing for Climate Liability News, reports, “The suit, which was filed in the European General Court in Luxembourg, asks the court to prevent EU countries from counting forest wood as a renewable energy source under the 2018 revised Renewable Energy Directive known as RED II.”  Major sources of wood pellets used in EU power plants are in the southeast U.S., where greatly increased logging activities are depleting established, slow-growth hardwood forests.  So the EU is OK with a “clean” energy policy that, in practice, increases current pollution locally in the EU while simultaneously stripping hardwood forests in a location outside of the EU. It seems to me that this is an environmental “double whammy” that can only make sense on paper, but not in practice.  You can read Karen Savage’s article here:


Regarding the EU Green Deal and Energy Union, I’m certain that the devil is in the details, and EU Member States need to have the opportunity to assess these details so there is no misunderstanding when EU climate laws are passed.  

The EU’s Green Deal has major flaws and needs to be recast to acknowledge the important role that nuclear power can play as a large, carbon-free source of electric power while also helping to ensure 24/7 grid stability.  Failing to recognize the role of nuclear power as a carbon-free source of electric power will serve to highlight the strong bias and hypocrisy of an EU energy leadership that has lost its way.  It also would serve as another example of why Brexit makes sense.

Even fossil power, with appropriate advanced environmental controls, should have a role in the Green Deal.  For example, a rapid shift away from coal to natural gas would significantly decrease near-term carbon dioxide emissions.  Similarly, abandoning the laughable EU policy on “carbon-neutral” biomass would eliminate a significant source of carbon dioxide emissions within the EU, and it would save environmentally valuable hardwood forests in the southeast U.S. and elsewhere.

Update: 16 December 2019 – Finally, some common sense prevailed, but only under very intense political pressure and, probably, fear of failure

In an article by Samuel Petrequin, “EU leaders include nuclear energy in green transition,” the Associated Press reported: 

“EU heads of state and government agreed that nuclear energy will be recognized as a way to fight climate change as part of a deal that endorsed the climate target. While Poland did not immediately agree to the plan, the concessions on nuclear energy were enough for the Czech Republic and Hungary to give their approval.  The two nations had the support of France, which relies on nuclear power for 60% of its electricity. They managed to break the resistance of skeptical countries, including Luxembourg, Austria and Germany to get a clear reference to nuclear power in the meeting’s conclusions. ‘Nuclear energy is clean energy,’ Czech Prime Minister Andrej Babiš said. ‘I don’t know why people have a problem with this.’”

You can read the complete AP article here:

The European Council memorandum contains only a single reference to “nuclear,” more in the form of a resigned acknowledgement rather than an endorsement.  

“The European Council acknowledges the need to ensure energy security and to respect the right of the Member States to decide on their energy mix and to choose the most appropriate technologies. Some Member States have indicated that they use nuclear energy as part of their national energy mix.”

You can read the European Council memorandum here:

Congratulations to the representatives from France, Czech Republic, Hungary, Poland and others for fighting the hard political fight and winning a place for nuclear power in the EU’s Green Deal.  But be watchful because the EU anti-nuclear forces are still there.

Update:  20 March 2020 – Yes, the EU anti-nuclear forces are still there.

On 10 March 2020 the European Commission issued a press release announcing its new industrial strategy, “Making Europe’s businesses future-ready: A new Industrial Strategy for a globally competitive, green and digital Europe.”  You can read the press release and download related documents here:

While the plan highlights the need to “secure a sufficient and constant supply of low-carbon energy at competitive prices,” the word “nuclear” is notably absent from the EU’s industrial strategy.  Not much of a surprise, considering the EU’s behavior on the Green New Deal.

The next day, on 11 March, the Brussels-based nuclear industry group Foratom called on the EU decision-makers to support the nuclear sector’s important role within the EU economy.  Foratom’s Director General,  Yves Desbazeille, noted, “Not only is it (nuclear) low-carbon, it is also flexible, dispatchable and cost-effective”.

Foratom highlighted the following key attributes of nuclear energy in the context of the EU industrial strategy:

  • Maintain the competitiveness of Europe’s industry as energy often accounts for a significant share of manufacturing costs,
  • Decarbonize industry and thus contribute towards the 2050 carbon neutrality target,
  • Provide industry with the energy it needs when it needs it, which is particularly important for processes which run 24/7,
  • Other industries by offering alternative sources of decarbonized energy such as hydrogen and heat (sector coupling).

You can read Foratom’s complete statement here:

This is further evidence that EU nuclear energy advocates are fighting an uphill battle for recognition by the entrenched EU bureaucracy that nuclear power is a zero-carbon source of power and it can make an important (and maybe essential) contribution to meeting the EU’s 2050 carbon neutrality goal.

Best wishes to Foratom in their efforts to secure a place in the EU industrial strategy for nuclear power.

Update 5 May 2020 – More support for EU nuclear power

SNETP (Sustainable Nuclear Energy Technology Platform) was established in 2007, with EC support, as a group of non-governmental organizations that promote and coordinate research on nuclear fission.  

On 24 April 2020, SNETP sent a letter, endorsed by more than 100 organizations, to the Vice-presidents of the European Commission and the EU Commissioner for Energy calling for a “just and timely assessment of nuclear energy in the EU Taxonomy of Sustainable Finance.”

When enacted, the EU’sTaxonomy Regulation is intended to be a tool to guide future energy investments by providing investors with information on which activities and technologies contribute to the EU’s sustainability goals.  In their March 2020 final recommendations, the technical expert group (TEG) currently advising the EC on sustainable energy finance did not include nuclear power as a low-carbon and sustainable electricity source.

You can download the SNETP letter and see the logos of the many endorsing organizations here:

Clearly, the battle lines have formed, with the anti-nuclear elements of the EU bureaucracy on one side and organizations like Foratom and SNETP on the other.  Against the behemoth EU bureaucracy, my best wishes go out to the underdogs, Foratom, SNETP, and other organizations and individuals that understand how nuclear power can play important roles in helping the EU achieve climate neutrality by 2050.

For more information:

75th Anniversary of the Kurchatov Institute

Peter Lobner

The I. V. Kurchatov Institute of Atomic Energy in Moscow was founded 75 years ago, in 1943, and is named for its founder, Soviet nuclear physicist Igor Vasilyevich Kurchatov.  Until 1955, the Institute was a secret organization known only as “Laboratory No. 2 of the USSR Academy of Sciences.”  The initial focus of the Institute was the development of nuclear weapons.

Kurchatov Institute 75thanniversary on Russian commemorative postage stamp.

I. V. Kurchatov and the team of scientists and engineers at the Institute led or supported many important historical Soviet nuclear milestones, including: 

  • 25 December 1946: USSR’s F-1 (Physics-1) reactor achieved initial criticality at Kurchatov Institute.  This was the 1st reactor built and operated outside the US.
  • 10 June 1948: USSR’s 1st plutonium production reactor achieved initial criticality (Unit A at Chelyabinak-65). The reactor was designed under the leadership of N. A. Dollezhal.
  • 29 August 1949: USSR’s 1st nuclear device, First Lightning [aka RDS-1, Izdeliye 501 (device 501) and Joe 1], was detonated at the Semipalatinsk test site in what is now Kazakhstan.  This was the 1st nuclear test other than by the US.
  • 27 June 1954: World’s 1st nuclear power plant, AM-1 (aka APS-1), was commissioned and connected to the electrical grid, delivering power in Obninsk.  AM-1 was designed under the leadership of N. A. Dollezhal.
  • 22 November 1955: USSR’s 1st thermonuclear device (RDS-37, a two-stage device) was detonated at the Semipalatinsk test site.  This also was the world’s 1stair-dropped thermonuclear device.
  • 5 December 1957: USSR’s 1st nuclear-powered icebreaker, Lenin, was launched.  This also was the world’s 1st nuclear-powered surface ship.
  • 4 July 1958: USSR’s 1st  nuclear-powered submarine, Project 627 SSN K-3, Leninskiy Komsomol, made its 1st underway on nuclear power.
  • 1958: World’s 1st Tokamak, T-1, initial operation at Kurchatov Institute.
I. V. Kurchatov and F-1 reactor on Russian commemorative postage stamp. Source:  Wikimedia Commons

I. V. Kurchatov served as the Institute’s director until his death in 1960 and was awarded Hero of Socialist Labor three times and Order of Lenin five times during his lifetime.

After I. V. Kurchatov’s death in 1960, the noted academician Anatoly P. Aleksandrov was appointed as the director of the Institute and continued in that role until 1989.  Aleksandrov already had a key role at the Institute, having been appointed by Stalin in September 1952 as the scientific supervisor for developing the USSR’s first nuclear-powered submarine and its nuclear power unit.

A. P. Aleksandrov and OK-150 reactor on Russian commemorative postage stamp. Source:  Wikimedia Commons

Until 1991, the Soviet Ministry of Atomic Energy oversaw the administration of Kurchatov Institute.  After the formation of the Russian Federation at the end of 1991, the Institute became a State Scientific Center reporting directly to the Russian Government.  Today, the President of Kurchatov Institute is appointed by the Russian Prime Minister, based on recommendations from Rosatom (the Russian State Energy Corporation), which was formed in 2007.

You’ll find a comprehensive history of Kurchatov Institute in a 2013 (70thanniversary) special issue of the Russian version of Scientific American magazine, which you can download here:

The evolution of Kurchatov Institute capabilities from its initial roles on the Soviet nuclear weapons program is shown in the following diagram.

Source: Special issue 2013,

Modern roles for Kurchatov Institute are shown in the following graphic.

Source: Special issue 2013,

In the past 75 years, the Kurchatov Institute has performed many major roles in the Soviet / Russian nuclear industry and, with a national security focus, continues to be a driving force in that industry sector.

Now, lets take a look at a few of the pioneering nuclear projects led or supported by Kurchatov Institute:

  • F-1 (Physics-1) reactor
  • Plutonium production reactors
  • Obninsk nuclear power plant AM-1
  • T-1 Tokamak

F-1 (Physics-1) reactor

The F-1 reactor designed by the Kurchatov Institute was a graphite-moderated, air-cooled, natural uranium fueled reactor with a spherical core about 19 feet (5.8 meters) in diameter. F-1 was the first reactor to be built and operated outside of the US.  It was a bit more compact than the first US reactor, the Chicago Pile, CP-1, which had an ellipsoidal core with a maximum diameter of about 24.2 feet (7.4 meters) and a height of 19 feet (5.8 meters).

The F-1 achieved initial criticality on 25 December 1946 and initially was operated at a power level of 10 watts.  Later, F-1 was able to operate at a maximum power level of 24 kW to support a wide range of research activities. In a 2006 report on the reactor’s 60thanniversary by RT News (, Oleg Vorontsov, Deputy Chief of the Nuclear Security Department reported, “Layers of lead as they are heated by uranium literally make F1 a self-controlling nuclear reactor. And the process inside is called – the safe-developing chain reaction of uranium depletion. If the temperature rises to 70 degrees Celsius (158° Fahrenheit), it slows down by its own! So it simply won’t let itself get out of control.” 

F-1 was never refueled prior to its permanent shutdown in November 2016, after 70 years of operation.

Top of the F-1 reactor core. Source:
F-1 reactor facility cross-section diagram.  The F-1 reactor is the igloo-shaped structure located in the open pit.  Source:
Graphite stacks of the F-1 reactor.  Source: Kurchatov Institute

Plutonium production reactors

The first generation of Soviet plutonium production reactors were graphite-moderated, natural uranium fueled reactors designed under the leadership of N.A. Dollezhal while he was at the Institute of Chemical Machinery in Moscow.  The Kurchatov Institute had a support role in the development of these reactors.The five early production reactors at Chelyabinsk-65 (later known as the Mayak Production Association) operated with a once-through primary cooling water system that discharged into open water ponds.

Simplified cross-section of a Russian graphite-moderated, water-cooled plutonium production reactor.  Source: PNL-9982

Four of the five later graphite-moderated production reactors at Tomsk had closed primary cooling systems that enabled them to also generate electric power and provide district heating (hot water) for the surrounding region.  You’ll find a good synopsis of the Soviet plutonium production reactors in the 2011 paper by Anatoli Diakov, “The History of Plutonium Production in Russia,” here:

Additional details on the design of the production reactors is contained in the 1994 Pacific Northwest Laboratory report PNL-9982, “Summary of Near-term Options for Russian Plutonium Production Reactors,” by Newman, Gesh, Love and Harms.  This report is available on the OSTI website here:

Obninsk nuclear power plant AM-1 (Atom Mirny or “Peaceful Atom”)

AM-1 nuclear power plant exterior view.  Source:
Panoramic view of the AM-1 power plant control room.  Source: via

Obninsk was the site of the world’s first nuclear power plant (NPP).  This NPP had a single graphite-moderated, water-cooled reactor fueled with low-enriched uranium fuel. The reactor had a maximum power rating of 30 MWt.  AM-1 was designed by N.A. Dollezhal and the Research and Development Institute of Power Engineering (RDIPE / NIKIET) in Moscow, as an evolution of an earlier Dollezhal design of a small graphite-moderated reactor for ship propulsion.  The Kurchatov Institute had a support role in the development of AM-1.

The basic AM-1 reactor layout is shown in the following diagram.

Source: Directory of Nuclear Reactors, Vol. IV, Power Reactors, International Atomic Energy Agency, 1962

The closed-loop primary cooling system delivered heat via steam generators to the secondary-side steam system, which drove a steam turbine generator that delivered 5 MWe (net) to the external power grid.   Following is a basic process flow diagram for the reactor cooling loops.

Source: Directory of Nuclear Reactors, Vol. IV, Power Reactors, International Atomic Energy Agency, 1962

Construction on AM-1 broke ground on 31 December 1950 at the Physics and Power Engineering Institute (PEI) in Obninsk, about 110 km southwest of Moscow.  Other early milestone dates were:

  • Initial criticality:  5 May 1954
  • Commissioning and first grid connection:  26 June 1954
  • Commercial operation:  30 November 1954

In addition to its power generation role, AM-1 had 17 test loops installed in the reactor to support a variety of experimental studies. After 48 years of operation, AM-1 was permanently shutdown on 28 April 2002.

You can read more details on AM-1 in the following two articles: “Obninsk: Number One,” by Lev Kotchetkov on the Nuclear Engineering International website here:

“Anniversary at Obninsk: The First Commercial Nuclear Power Plant,” by Will Davis on the ANS Nuclear Café website here:

The AM-1 nuclear power plant design was developed further by NIKIET into the much larger scale RBMK (Reaktor Bolshoy Moshchnosti Kanalnyy, “High Power Channel-type Reactor”) NPPs.  The four reactors at the Chernobyl NPP were RBMK-1000 reactors.

The T-1 Tokamak

Research on plasma confinement is a toroidal magnetic field began in Russia in 1951, leading to the construction of the first experimental toroidal magnetic confinement system, known as a tokamak, at Kurchatov Institute. T-1 began operation in 1958.  

T-1 Tokamak.  Source:

Early operation of T-1 and successive models revealed many problems that limited the plasma confinement capabilities of tokamaks.  Solving these problems led to a better understanding of plasma physics and significant improvements in the design of tokamak machines.  You’ll find a historical overview of early Soviet / Russian work on Tokamaks in a 2010 IAEA paper by V. P. Smirnov, ”Tokamak Foundation in USSR/Russia 1950–1990,” which you can read here:

The basic tokamak design for magnetic plasma confinement has been widely implemented in many international fusion research machines, winning out over other magnetic confinement concepts, including the Stellarator machine championed in the US by Dr. Lyman Spitzer (see my 30 August 2017 post on Stellarators).  Major international tokamak projects include the Joint European Torus (JET) at the Culham Center for Fusion Energy in Oxfordshire, UK, the Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory in the US, the JT-60 at the Japan Atomic Energy Agency’s Naka Fusion Institute, and most recently the International Thermonuclear Experimental Reactor (ITER) being built now at the Saclay Nuclear Center in southern France.

Marine Nuclear Power: 1939 – 2018

Peter Lobner

In 2015, I compiled the first edition of a resource document to support a presentation I made in August 2015 to The Lyncean Group of San Diego ( commemorating the 60thanniversary of the world’s first “underway on nuclear power” by USS Nautilus on 17 January 1955.  That presentation to the Lyncean Group, “60 years of Marine Nuclear Power: 1955 –2015,” was my attempt to tell a complex story, starting from the early origins of the US Navy’s interest in marine nuclear propulsion in 1939, resetting the clock on 17 January 1955 with USS Nautilus’ historic first voyage, and then tracing the development and exploitation of marine nuclear power over the next 60 years in a remarkable variety of military and civilian vessels created by eight nations.

Here’s a quick overview of worldwide marine nuclear in 2018.

Source: two charts by author

In July 2018, I finished a complete update of the resource document and changed the title to, “Marine Nuclear Power: 1939 –2018.”  Due to its present size (over 2,100 pages), the resource document now consists of the following parts, all formatted as slide presentations:

  • Part 1: Introduction
  • Part 2A: United States – Submarines
  • Part 2B: United States – Surface Ships
  • Part 3A: Russia – Submarines
  • Part 3B: Russia – Surface Ships & Non-propulsion Marine Nuclear Applications
  • Part 4: Europe & Canada
  • Part 5: China, India, Japan and Other Nations
  • Part 6: Arctic Operations

The original 2015 resource document and this updated set of documents were compiled from unclassified, open sources in the public domain.

I acknowledge the great amount of work done by others who have published material in print or posted information on the internet pertaining to international marine nuclear propulsion programs, naval and civilian nuclear powered vessels, naval weapons systems, and other marine nuclear applications.  My resource document contains a great deal of graphics from many sources.  Throughout the document, I have identified the sources for these graphics.

You can access all parts of Marine Nuclear Power: 1939 – 2018 here:

Marine Nuclear Power 1939 – 2018_Part 1_Introduction

Marine Nuclear Power 1939 – 2018_Part 2A_USA_submarines

Marine Nuclear Power 1939 – 2018_Part 2B_USA_surface ships

Marine Nuclear Power 1939 – 2018_Part 3A_R1_Russia_submarines

Marine Nuclear Power 1939 – 2018_Part 3B_R1_Russia_surface ships & non-propulsion apps

Marine Nuclear Power 1939 – 2018_Part 4_Europe & Canada

Marine Nuclear Power 1939 – 2018_Part 5_China-India-Japan & Others

Marine Nuclear Power 1939 – 2018_Part 6 R1_Arctic marine nuclear

I hope you find this resource document informative, useful, and different from any other single document on this subject.  Below is an outline to help you navigate through the document.

Outline of Marine Nuclear Power:  1939 – 2018.

Part 1: Introduction

  • Quick look:  Then and now
  • State-of-the-art in 1955
  • Marine nuclear propulsion system basics
  • Timeline
    • Timeline highlights
    • Decade-by-decade
  • Effects of nuclear weapons and missile treaties & conventions on the composition and armament of naval fleets
  • Prospects for 2018 – 2030

Part 2A: United States – Submarines

  • Timeline for development of marine nuclear power in the US
  • US current nuclear vessel fleet
  • US naval nuclear infrastructure
  • Use of highly-enriched uranium (HEU) in US naval reactors
  • US submarine reactors and prototype facilities
  • US Navy nuclear-powered submarines
    • Nuclear-powered fast attack submarines (SSN)
      • Submarine-launched torpedoes, anti-submarine missiles & mines
      • Systems to augment submarine operational capabilities
    • Nuclear-powered strategic ballistic missile submarines (SSBN)
      • Submarine-launched strategic ballistic missiles (SLBMs)
    • Nuclear-powered guided missile submarines (SSGN)
      • Cruise missiles and other tactical guided missiles
    • Nuclear-powered special operations submarines

Part 2B: United States – Surface Ships

  • US naval surface ship reactors & prototype facilities
  • US Navy nuclear-powered surface ships
    • Evolution of the US nuclear-powered surface fleet
    • Nuclear-powered guided missile cruisers (CGN)
      • CGN tactical weapons
    • Nuclear-powered aircraft carriers (CVN)
      • Carrier strike group (CSG) & carrier air wing composition
  • Naval nuclear vessel decommissioning and nuclear waste management
  • US civilian marine nuclear vessels and reactors
    • Operational & planned civilian marine vessels and their reactors
    • Other US civilian marine reactor designs
  • Radioisotope Thermoelectric Generator (RTG) marine applications
  • US marine nuclear power current trends

Part 3A: Russia – Submarines

  • The beginning of the Soviet / Russian marine nuclear power program
  • Russian current nuclear vessel fleet.
  • Russian marine nuclear reactor & fuel-cycle infrastructure
  • Russian nuclear vessel design, construction & life-cycle infrastructure
  • Russian naval nuclear infrastructure
  • Russian nuclear-powered submarines
    • Submarine reactors
    • Nuclear-powered fast attack submarines (SSN)
      • Submarine-launched torpedoes & anti-submarine missiles
    • Strategic ballistic missile submarines (SSB & SSBN)
      • Submarine-launched ballistic missiles (SLBM)
    • Cruise missile submarines (SSG & SSGN).
      • Cruise missiles
    • Nuclear-powered special operations subs & strategic torpedoes
    • Other special-purpose nuclear-powered subs
    • Examples of un-built nuclear submarine projects

Part 3B: Russia – Surface Ships & Non-propulsion Marine Nuclear Applications

  • Russian nuclear-powered surface ships
    • Surface ship reactors
    • Nuclear-powered icebreakers
    • Nuclear-powered naval surface ships
      • Nuclear-powered guided missile cruisers
      • Nuclear-powered command ship
      • Nuclear-powered aircraft carrier
      • Nuclear-powered multi-purpose destroyer
  • Russian non-propulsion marine nuclear applications
    • Small reactors for non-propulsion marine nuclear applications
    • Floating nuclear power plants (FNPP)
    • Transportable reactor units (TRU)
    • Arctic seabed applications for marine nuclear power
    • Radioisotope Thermoelectric Generators (RTG)
  • Marine nuclear decommissioning and environmental cleanup
  • Russian marine nuclear power current trends

Part 4: Europe & Canada

  • Nations that operate or have operated nuclear vessels
    • United Kingdom
      • The beginning of the UK marine nuclear power program
      • UK current nuclear vessel fleet
      • UK naval nuclear infrastructure
      • UK naval nuclear reactors
      • UK Royal Navy nuclear-powered submarines
        • Nuclear-powered fast attack submarines (SSN)
          • Submarine-launched tactical weapons
        • Nuclear-powered strategic ballistic missile submarines (SSBN)
          • Submarine-launched ballistic missiles (SLBM)
      • UK disposition of decommissioned nuclear submarines
      • UK nuclear surface ship and marine reactor concepts
      • UK marine nuclear power current trends
    • France
      • The beginning of the French marine nuclear power program
      • French current nuclear vessel fleet
      • French naval nuclear infrastructure
      • French naval nuclear reactors
      • French naval nuclear vessels
        • Nuclear-powered strategic ballistic missile submarines (SNLE)
          • Submarine-launched ballistic missiles (MSBS)
        • Nuclear-powered fast attack submarines (SNA)
          • Submarine-launched tactical weapons
        • Nuclear-powered aircraft carrier
      • French disposition of decommissioned nuclear submarines
      • French non-propulsion marine reactor applications
      • French marine nuclear power current trends
    • Germany
  • Other nations with an interest in marine nuclear power technology
    • Italy
    • Sweden
    • Netherlands
    • Canada

Part 5: China, India, Japan and Other Nations

  • Nations that have operated nuclear vessels
    • China
      • The beginning of China’s marine nuclear power program
      • China’s current nuclear vessel fleet
      • China’s naval nuclear infrastructure
      • China’s nuclear vessels
        • Nuclear-powered fast attack submarines (SSNs)
          • Submarine-launched tactical weapons
        • Nuclear-powered strategic ballistic missile subs (SSBNs)
          • Submarine-launched ballistic missiles (SLBMs)
        • Floating nuclear power stations
        • Nuclear-powered surface ships
      • China’s decommissioned nuclear submarine status
      • China’s marine nuclear power current trends
    • India
      • The beginning of India’s marine nuclear power program
      • India’s current nuclear vessel fleet
      • India’s naval nuclear infrastructure
      • India’s nuclear-powered submarines
        • Nuclear-powered fast attack submarines (SSNs)
          • Submarine-launched tactical weapons
        • Nuclear-powered strategic ballistic missile submarines (SSBNs)
          • Submarine-launched ballistic missiles (SLBM).
      • India’s marine nuclear power current trends
    • Japan
  • Other nations with an interest in marine nuclear power technology
    • Brazil
    • North Korea
    • Pakistan
    • Iran
    • Israel
    • Australia

Part 6: Arctic Operations

  • Rationale for marine nuclear power in the Arctic
  • Orientation to the Arctic region
  • US Arctic policy
  • Dream of the Arctic submarine
  • US marine nuclear Arctic operations
  • UK marine nuclear Arctic operations
  • Canada marine nuclear ambitions
  • Russian marine nuclear Arctic operations
    • Russian non-propulsion marine nuclear Arctic applications
  • China’s marine nuclear ambitions
  • Current trends in marine nuclear Arctic operations

Periodic updates:

  • Parts 3A and 3B, Revision 1, were posted in October 2018
  • Part 6, Revision 1, was posted in February 2019