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Atomic energy technology, politics, and perceptions from a nuclear energy insider who served as a US nuclear submarine engineer officer

What makes smaller nuclear power systems so exciting?

Tue, 09/21/2021 - 09:40

Let me start by dispelling the notion that I think smaller, modular, manufactured nuclear power systems – often called SMRs or micro reactors – are the be all and end all solution to anything, including climate change or energy security.

Though not THE solution, they have the potential to be a crucial, uniquely capable part of a fully-integrated, 0% emission climate-solving grid. 

The best of the breed build on lessons from aircraft manufacturing, submarine construction, electric vehicles, wind & solar and even computers. They are leavened with six decades worth of experience in building, operating and maintaining extra large nuclear systems. They address some of the public relations challenges that have plagued very large reactors.

Some of the system designers are paying close attention to the social science lessons and teachings of groups like “The Good Energy Collective” and designing their systems with customer needs and wants in mind. They often state that they are planning to build reactors that people want to buy. Many of the people or communities interested in buying those reactors are planning to live, work, and play right next to the power system. (Regarding the “play” part of that statement – at least one of the proposals I’ve seen includes directing the waste heat from the power system to a community swimming pool.)

Economy of series production & operation

As former submarine engineer officer who also had the rare opportunity to plan and budget for fleet level nuclear power training, maintenance and construction programs, I have a personal understanding of how economies of series production and standardization work to help keep costs under control and schedules predictable.

It is enlightening to see how much costs fall when you can train a group of operators in a common speciality and send them out to several dozen plants that have identical equipment, spare parts lockers and layouts. It’s also easy to see how maintenance procedures can be written once and used by all and how alterations can be planned, reviewed and implemented. These are just a few of the examples I can list. Rules protecting confidential information prevent me from sharing quantified details. Space prevents me from listing other examples.

It shouldn’t surprise anyone who has made anything that people learn to do things with experience or that doing the same thing repeatedly produces better results the more often the task is done. Those learning curve-related improvements don’t require mass production of thousands or millions of units, they start improving cost and performance with the second unit.

Widely cited literature from thought leaders like Clay Christensen (Innovators Dilemma and other works) show that there is a relation between costs and doubling of cumulative unit production.

The modern renewable industry – wind and solar energy collection systems – demonstrate the utility of replication. Starting from the high cost systems of the early 2000s, the industry took advantage of tax credit and mandates originally designed to help them build markets and achieve scale economies. Their impressive cost reduction performance is more attributable to the economy of learning by doing than it is to technological innovations and new inventions.

Aside: Some of the techniques used for the dramatic cost improvements in wind and especially solar power systems are not actions that we will to use to drive down nuclear costs. The sector has an admirable tradition of paying living wages to people who eagerly accept the responsibilities that come with high quality work and a strong safety culture. It also does not concentrate its manufacturing in countries with lower standards. End Aside.

Of course, cost and schedule improvements that result from experience can be lost, team relationships can be broken and skills can atrophy with a lack of practice. Smaller nuclear power systems will not be immune to these advantages and vulnerabilities. But unlike far larger plants that might be able to serve five, ten, or even fifteen years worth of electricity demand growth with a single unit, smaller systems will need numerous units to be steadily brought into service.

Smaller nuclear systems do not replace extra large power plants

Some challenge the idea that we should add small reactors to our product catalog. They believe that we know how to build large reactors, we have proven that we can operate them with incredible safety records and each one can make a big difference in both energy supply security and CO2 emissions. They claim that smaller reactors make the tasks more difficult and that many of the smaller reactors still need many years of operating experience to catch up with larger units.

SMRs and micro reactors are not intended as replacement products for situations when customers want large or very large power units. They are an addition to the options list for those who want or need their power in smaller quantities or who want to learn how to build and operate nuclear plants in a more gradual fashion.

Some object to those of us who characterize modern nuclear power systems as “advanced” because they claim we have done them all before. While it is true that world nuclear energy history includes projects that envisioned or actually used many of the potential combinations of fuel form, coolant, fuel enrichments, and secondary power systems, it isn’t true that they explored all available technological advances. Today’s designs benefit from innovations and developments that were not available back when some of the original research and testing was done.

The fact that there was a thriving market for electric cars that took off in the 1890s, even before the Model T years, does not make the Tesla any less advanced of a vehicle.

Aside: There are numerous smaller and micro reactors that are already in operation today. Two most recently completed examples are Russia’s Akademil Lomonosov and China’s HTR-PM. But the hundreds of reactors that have propelled naval vessels in a half dozen or more countries for decades also demonstrate many of the principles that make commercial SMR worthy of excitement. Indian PHWRs also have many of the characteristics of modern SMRs, including power rating. End Aside.

Note: The Wright Brothers and Henry Ford built internal combustion engines 120 or more years ago. That does not negate the statements by current automobile manufacturers that their power plants are advanced or modern. Modern electric vehicles may be descended from earlier products built on roughly the same combination of features, but they are still marvels of advanced technology.

Security, Insurance and Non-Proliferation

Some claim that rules aimed at ensuring security and preventing the proliferation of nuclear weapons will make smaller systems unaffordable. They overlook the efforts that are going into the system designs to make security easier to implement, the ways that safeguards are being designed into the systems and the fact that some of the rules are being changed because responsible leaders have recognized that they do not actually improve safety or security. Some of them were implemented with the express purpose of slowing nuclear energy development. The immediacy of climate change is stimulating efforts to identify and alter requirements that serve primarily to undermine nuclear economics.

There are even some who cling to the shibboleth claiming that nuclear energy is somehow subsidized because it has a specially designed group insurance program under the 1957 Price Anderson Act (as amended over the years.) While there are changes needed in that Act, it has never been a subsidy for nuclear energy. The truth is that insuring nuclear power plants has never cost taxpayers a dime in paid damages and the insurers that specialize in providing the required commercial insurance have been hugely profitable by collecting premiums and rarely, if ever, paying a claim.

When opponents point to the long-term costs of the accident at Fukushima Dai-ichi as a reason to believe that nuclear plants are under insured, they have some basis in fact. But most of the nuclear-related cleanup costs associated with that accident have been self imposed by the Japanese national, prefecture and local governments. They set radiation exposure standards that were much more stringent than already conservative international standards. Simply using international standards for radiation doses would have greatly reduced evacuation and relocation costs. Basing those actions on a more complete understanding of radiation and its risks would have virtually eliminated costs of actions taken outside of the plant fences.

Rebuilding an area decimated by an earthquake and tsunami isn’t cheap, but it shouldn’t be attributed to events at an industrial facility that did not harm its neighbors.

Are SMRs a good investment?

The answer is, it depends. As with every industry that is experiencing a new generation of technological innovation, some entrepreneurial teams are progressing well, successfully pitching their vision to investors, building their teams, executing against their milestones, learning from set-backs, adjusting to regulatory and market conditions and keeping their eye on the ball. And others not so much.

At Nucleation Capital, the partner team has a combined total of several decades spent investigating and observing the growing potential for advanced nuclear power production. We know that nuclear energy is clean enough to run inside sealed submarines full of people and safe enough for caring parents to not worry when their children work in close proximity to an operating nuclear power plant. We also know that commercial nuclear plants have amassed an admirable safety and reliability record.

That gives us tremendous hope and confidence that great teams will emerge that can learn from our historical performance, from the navy and otherwise, and that new designs will emerge that competitively meet the challenge to deliver clean energy reliably and cost-effectively with newer implementations of amazing carbon-free technology. But we also recognize that not every design will work as hoped or be well-suited to the market demand that exists. Not every team will have what it takes to be successful in a complex market.

Furthermore, we understand the concerns that many people have about the unknowns regarding new designs and the risks of deploying many more small reactors in an widening array of applications. Just as with the deployment of electric vehicles which cannot succeed on the basis of a car design alone but must be matched with a robust national grid of charging stations, this next generation of nuclear ventures will need to solve for an array of related challenges, including nuclear fuel production, long-term waste handling and storage, spent fuel transportation and reprocessing, among other things.

Fortunately, there are quite a lot of groups and entities that are eager to work on these issues, so that new nuclear systems can help us address climate change, provide humanity with reliable power in a climate-stressed world and also succeed in winning public support. There are valid concerns and there are good ways to address them. We also believe that we will have more success overcoming these concerns if coalitions of people across all spectrums participate in helping to solve them collaboratively. 

We are very pleased to be in a position to talk with founders, get briefed on detailed, often non-public information and discuss with them their development goals and challenges, as well as their experiences dealing with a range of potential funders, regulators, suppliers, strategic partners and potential customers. 

Of course, we cannot be specific about those interactions, but we can express how confident and energized they make us feel for this next generation of reactor developers to broaden the zero-carbon toolset to help reverse the trend of ever increasing CO2 emissions. In the foreseeable future, those new designs will likely contribute to the gargantuan task of reducing the existing emitted inventory of over a trillion tons of greenhouse gases already afflicting our climate, by working in combination with a range of carbon capture and removal technologies.

Our investments do not give us a “conflict of interest.” Rather, we believe they give us a broadening window into the future of decarbonization. We will continue to work with the ventures in our portfolio to help them navigate in the ever-shifting policy, regulatory and investment environments. We will keep our eye on the progress towards commercialization goals and continue to drill down into technological and competitive progress being made, so we can better determine our future investment activity.

We are not policy makers nor government officials. We have “skin in the game.” We will be participating to the extent of working to make sure that the developing advanced nuclear energy industry focuses on meeting customer needs and wants and ensuring that there are cost-effective methods for delivering these over the longer term.

We are also enthused by the opportunity to expand the world of “clean energy” and “climate tech” investing to include nuclear energy. We know that a large portion of the clean, near zero-emission energy produced in the world today comes from long ago investments in nuclear power plants that have been operating reliably for decades. While some look at the hiatus in new builds and believe it indicates that nuclear power is on its way out, we look at the same hiatus as the impetus to improve upon and achieve major strides towards perfecting this extraordinary but still overlooked technology. We will be working our hardest to make sure that we and our investors are able to participate in the growth and success of those ventures which best meet the climate challenge with the right set of products and services.

China’s high temperature reactor – pebble bed modular (HTR-PM) achieves its first criticality

Tue, 09/14/2021 - 11:56

On the morning of September 12, 2021, reactor number 1 of the eagerly awaited HTR-PM project was taken critical for the first time. Initial criticality for any new reactor is a big deal for the people involved in the project; this one is a big deal for the future of nuclear energy. It might also become a big deal for humanity’s ability to effectively reduce CO2 emissions enough to slow climate change.

HTR-PM is a demonstration reactor that uses two identical gas-cooled high temperature modular reactors to produce the heat for a modern, super critical, 200 MWe steam turbine. The steam system operates at the same temperature and pressure as the recently constructed coal heated steam plants that China has been mass producing for more than a decade as it rapidly industrialized and became one of the world’s leaders in manufacturing, metals production and chemicals.

The press release from China National Nuclear Corporation (CNNC) includes the following statement.

They [HTRs) have broad commercial application prospects in nuclear power generation, combined heat, power and cooling, and high-temperature process heat. They are my country’s optimization of energy structure and guarantee of energy supply. An important path to safety and to achieve the “dual carbon” goal.

China National Nuclear Corporation press release dated 09-13-21 (https://www.cnnc.com.cn/cnnc/xwzx65/ttyw01/1112318/index.html) Note: Original in Chinese simplified, translated by Google Translate

Though the announcement does not specifically include coal furnace replacement, producing steam at the same temperature and pressure as used by modern coal plants qualifies as “high-temperature process heat.”

HTR-PM criticality is the most recent step in a long process of commercializing high temperature gas cooled reactors. Though they have a long history, proponents (like me) believe they are an advanced type of commercial atomic fission power technology. (See the high temperature gas reactor history description below.)

China has been purposefully working on high temperature gas reactor technology development for the past 30 years. They have absorbed lessons from HTR experience in Japan, the United States, the UK, and South Africa while also building their own domestic intellectual property and manufacturing capability. According to the China Huangeng Group Co. LTD (CHGC) press release, the project’s direction includes a strong emphasis on building indigenous capacity to build HTR without outside assistance.

As the world’s first pebble-bed modular high-temperature gas-cooled reactor, the demonstration project used more than 2,000 sets of equipment for the first time, and more than 600 sets of innovative equipment, including the world’s first high-temperature gas-cooled reactor spiral-coil once-through steam generator. The first high-power, high-temperature thermal magnetic bearing structure main helium fan, the world’s largest and heaviest reactor pressure vessel, etc., are of great significance to promote my country to seize the world’s leading advantage in the fourth-generation advanced nuclear energy technology.

China Huangeng Group Co. LTD press release dated 09/12/21 (https://www.chng.com.cn/detail_jtyw/-/article/ccgb60va5Gwc/v/962479.html) Note: Original in Chinese simplified, translated by Google Translate

Aside: The above includes a statement that helps explain why HTRs have not been universally popular and why they still face headwinds, even from nuclear energy advocates. Each reactor module produces about 250 MWth, which compares to about 3300 MWth in a 1000 MWe PWR or BWR. Even with higher temperatures and higher efficiency, each core can produce 1/10th of the electricity of light water reactors, but the first HTR pressure vessel is described as “the world’s largest and heaviest pressure vessel.” Pressurized gas has a far lower capacity to move heat than pressurized water.

But there are more factors to be considered in atomic fission power plant economics than the size and weight of the pressure vessel. End Aside.

China is rightfully proud of its accomplishment in achieving HTR-PM initial criticality. There are many more steps in the journey, but this step is important. It marks one more milestone in the process of creating nuclear fission power stations that can take full advantage of the world’s vast coal fired power station infrastructure.

Brief high temperature reactor history

Arguably, the basic idea for HTRs was initially proposed during the earliest days of nuclear power development – immediately following WWII. Dr. Farrington Daniels proposed a high temperature gas reactor as the heat source for what was then a modern steam system. The Daniels Pile project was initially funded by the Manhattan Commission and gathered some momentum before being abruptly cancelled by the nascent Atomic Energy Commission in early 1947.

In the late 1950s Germany’s Rudolf Schulten followed through on the idea and led the project to build the world’f first high temperature pebble bed reactor, the AVR. That small (46 MWth, 15 MWe) prototype operated for about 20 years. Its construction began in 1960, it was connected to the grid in 1967 and it was shut down in 1988.

The US and the UK built their own version of high temperature reactor prototypes, the US at Peach Bottom and the UK’s Dragon reactor at Winfrith in Dorset.

General Atomics, the US company that designed and built the successful prototype at Peach Bottom built a scaled up, significantly different design at Ft. St. Vrain (330 MWe). That reactor had a dismal operating history due to several FOAK system design problems. By the time the defects were corrected, the designer had lost all of the follow on orders. The plant owners had lost patience, didn’t want to own and operate an orphan plant design and shut the system down.

Germany built a larger, 300 MWe pebble bed reactor (THTR) but that reactor had unfortunate timing. It began operating in 1985 with a 1000 day temporary operating license. Before THTR had operated long enough to complete testing and rise to full power operation, the Chernobyl reactor exploded. Reports claimed that the graphite moderator was a primary contributor to the accident and there was a widespread, durable misinterpretation that the graphite actually caught fire.

THTR was a graphite moderated reactor. Owners could not convince the public or the regulators that there are fundamental differences between graphite moderated, helium cooled reactors and graphite moderated, water cooled reactors. THTR was shut down in September 1989 when its initial license expired and that license was not extended.

In the 1990s, South Africa invested several billion dollars and a lot of engineering effort in developing the pebble bed modular reactor (PBMR). A primary reason that effort did not achieve success is that it started with the notion that it was reasonable to build a 200 MWe turbine generator with high pressure helium as the working fluid and then to mount that large machine vertically inside a pressure vessel. That concept works on paper, but executing it proved to be extremely difficult and expensive. Before the project ended, designers had decided to mount the helium turbomachine in a more conventional, horizontal alignment, but the South African government had lost patience by that time.

Chinese technologists, led by Prof. Zhang Zuoyi, learned from PBMR’s experience. They chose to step back to what had worked well for the AVR and to gradually make improvements. They built the HTR-10, a 10 MWe prototype system with a helium to water steam generator that helped them learn on an affordable scale while planning for the next iteration.

HTR-10 has operated well as a prototype. Its capacity factor has been modest, but it wasn’t conceived as a steady state, commercial electricity producer. It has been used to test fuels, test materials, test equipment, train operators and refine operating procedures. In other words, it has done what prototypes are supposed to do.

Construction on HTR-PM began in 2012. It has taken a bit longer than initially planned, but part of the delay rests with the fact that some of the necessary components – like the unique, spiral-coil once-through steam generator – were difficult to design and refine into something that could be efficiently replicated.

The Shidaowan site is planned to eventually host 16 more HTR-PMs. There are already plans underway to design and build an HTR-PM600. That system will use pebble bed reactor models – each the same as the reactor modules used for the HTR-PM) to provide the required heat for a 600 MWe steam turbine power station.

A Path from Coal to Nuclear is Being Blazed in Wyoming

Thu, 08/12/2021 - 00:18



Many of those who care about finding solutions to the physical distress that our climate is experiencing, as reported on this week in a landmark 1,300 page report by the IPCC‘s Sixth Assessment Working Group 1 (Climate Change 2021: The Physical Science Basis), are not looking at Wyoming.

But based upon the announcement made in early June by Wyoming Governor Mark Gordon, together with senior Senator John Barrasso, Secretary of Energy Jennifer Granholm, TerraPower founder and Chairman, Bill Gates, President and CEO of Rocky Mountain Power Gary Hoogevene and others, maybe they should.

In a well-orchestrated 30-minute event, Wyoming’s political leadership, while making no bones about their total support for coal, announced that Bill Gates’ advanced nuclear venture, TerraPower, had selected Wyoming and a yet-to-be-determined retiring Rocky Mountain Power coal plant, as the site to build and operate the first sodium-cooled advanced Natrium™ reactor, with matching funding from the DOE’s ARDP program.

Aside: Several times during the presentation, a speaker mentioned their interest in carbon capture and sequestration. Many of the technologies being pursued for that capability require nearly continuous clean power in massive quantities. Nuclear plants are the leading source for that kind of power. End Aside

The Governor’s plan to test the conversion of coal plants to new nuclear is being supported with a combination of private and federal funding as well as advance work by Wyoming’s legislature, which passed HB 74 with overwhelming bipartisan support, allowing utilities and other power plant owners to replace retiring coal and natural gas electric generation plants with small modular nuclear reactors (SMRs). The bill was signed by the Governor immediately and is now House Enrolled Act 60.

Wyoming will see the development of a first-of-a-kind advanced nuclear power plant that validates the design, construction and operational features of the Natrium technology and enables Wyoming, which currently leads the country in coal exports, to get a lead in the form of energy best suited to replace coal—built right at coal plants, potentially around the world. This conversion path not only reuses some of the physical infrastructure at the coal plant but also takes advantage of the skilled people and supporting community that have been operating that plant.

In December, 2020, Staffan Qvist, Paweł Gładysz, Łukasz Bartela and Anna Sowizdzał published a study that looked at the issue of retrofitting coal power plants for decarbonization in Poland.  They published their findings in Retrofit Decarbonization of Coal Power Plants—a Case Study for Poland, showing that decarbonization retrofits worked best using high-temperature small modular reactor to replace coal boilers.

What makes this announcement truly “game-changing and monumental” in the Governor’s own words, is just how cost-effective and efficient converting a coal plant to advanced nuclear might be. According to the Polish study, retrofitting coal boilers with high-temperature small modular nuclear reactors as a way to decarbonize the plant can lower upfront capital costs by as much as 35% and reduce the levelized cost of electricity by as much as 28% when compared to a greenfield installation.

The analysis looked at the potential within a coal retrofit of re-using the existing assets that are already there. While there will be large differences across plants as to the effective age and useful life condition of major plant components, the study found that “compared to very early retirement, re-using non-coal-related auxiliary buildings and electrical equipment, turbogenerators, cooling water systems, cooling towers, and pumphouses can thus avoid the stranding of up to 40% of the initial investment at a new coal plant.” (See Qvist p. 7)



Additionally, converting to nuclear can maintain the level of energy output from the plant and even exceed it, while eliminating emissions. In contrast, annual output replacement would not be possible using other clean energy options such as biomass, wind, solar or geothermal. (See Qvist p. 11)


In October, 2020, the U.S. Department of Energy (DOE), awarded TerraPower $80 million in initial funding from the Advanced Reactor Demonstration Program (ARDP) to demonstrate the Natrium reactor and energy system with its technology co-developer GE Hitachi Nuclear Energy (GEH) and engineering and construction partner Bechtel. The award will provide TerraPower and its partners with up to $1.6 billion in federal funding during the project to build the reactor, to be operational within five to seven years. TerraPower is also partnering with PacifiCorp and Rocky Mountain Power, subsidiaries of Berkshire Hathaway Energy, Energy Northwest and Duke Energy, which will also provide expertise in the areas of licensing, operations, maintenance, siting and grid needs.

Currently, the DOE is funding a number of promising reactor development projects and President Biden’s recently passed Infrastructure Bill appears to have increased those budget allocations. That is very good news for the climate. According to the Qvist study, some 1,300 GW of coal power units globally could be suitable for retrofitting with advanced nuclear reactors by the 2030s. If large-scale retrofitting were to be implemented starting then, up to 200 billion tons of CO2 emission could be avoided, which equates to nearly six years of total global CO2 emissions, and “would make the prospects of reaching global climate targets far more realistic.” (Qvist p. 33)

For those of us anxiously logging milestones along the way towards our future 100% clean grid, TerraPower’s decision to site its new plant in Wyoming and Wyoming’s embrace of this opportunity—where not that long ago the legislature reacted with an “‘unheard of’ IRP investigation” to push back on PacifiCorp’s 2020 IRP showing the retirement of 20 of 24 coal plants—is remarkable. It is definitely worthwhile keeping an eye on Wyoming, where some entirely miraculous brew of audacious political leadership, climate-fueled economic anxiety and job-seeking technological brinkmanship appears to have paved the way for Wyoming to become a birthplace of 21 century clean energy. As Governor Gordon said, this is truly “game-changing and monumental” news—not just for Wyoming but also for the world. You can view the full announcement below.