Archive for the ‘REACTOR TYPES’ Category

Thorium Molten Salt Nuclear reactor (MSR) No Better Than Uranium Process

November 3, 2018

The safety issue is also not resolved, as stated above: pressurized water leaking from the steam generator into the hot, radioactive molten salt will explosively turn to steam and cause incredible damage.  The chances are great that the radioactive molten salt would be discharged out of the reactor system and create more than havoc.  Finally, controlling the reaction and power output, finding materials that last safely for 3 or 4 decades, and consuming vast quantities of cooling water are all serious problems.  

The greatest problem, though, is likely the scale-up by a factor of 500 to 1, from the tiny project at ORNL to a full-scale commercial plant with 3500 MWth output.   Perhaps these technical problems can be overcome, but why would anyone bother to try, knowing in advance that the MSR plant will be uneconomic due to huge construction costs and operating costs, plus will explode and rain radioactive molten salt when (not if) the steam generator tubes leak.

The Truth About Nuclear Power – Part 28, Sowells Law Blog , 14 July 2014 Thorium MSR No Better Than Uranium Process, 

Preface   This article, number 28 in the series, discusses nuclear power via a thorium molten-salt reactor (MSR) process.   (Note, this is also sometimes referred to as LFTR, for Liquid Fluoride Thorium Reactor)   The thorium MSR is frequently trotted out by nuclear power advocates, whenever the numerous drawbacks to uranium fission reactors are mentioned.   To this point in the TANP series, uranium fission, via PWR or BWR, has been the focus.  Some critics of TANP have already stated that thorium solves all of those problems and therefore should be vigorously pursued.  Some of the critics have stated that Sowell obviously has never heard of thorium reactors.   Quite the contrary, I am familiar with the process and have serious reservations about the numerous problems with thorium MSR.

It is interesting, though, that nuclear advocates must bring up the MSR process.  If the uranium fission process was any good at all, there would be no need for research and development of any other type of process, such as MSR and fusion. (more…)


Debunking the claims about generation IV nuclear waste

November 3, 2018

Generation IV nuclear waste claims debunked, Nuclear Monitor 24 Sept 18   Lindsay Krall and Allison Macfarlane have written an important article in the Bulletin of the Atomic Scientists debunking claims that certain Generation IV reactor concepts promise major advantages with respect to nuclear waste management. Krall is a post-doctoral fellow at the George Washington University. Macfarlane is a professor at the same university, a former chair of the US Nuclear Regulatory Commission from July 2012 to December 2014, and a member of the Blue Ribbon Commission on America’s Nuclear Future from 2010 to 2012.

Krall and Macfarlane focus on molten salt reactors and sodium-cooled fast reactors, and draw on the experiences of the US Experimental Breeder Reactor II and the US Molten Salt Reactor Experiment.

The article abstract notes that Generation IV developers and advocates “are receiving substantial funding on the pretense that extraordinary waste management benefits can be reaped through adoption of these technologies” yet “molten salt reactors and sodium-cooled fast reactors – due to the unusual chemical compositions of their fuels – will actually exacerbate spent fuel storage and disposal issues.”

Here is the concluding section of the article:

“The core propositions of non-traditional reactor

proponents – improved economics, proliferation resistance,

safety margins, and waste management – should be

re-evaluated. The metrics used to support the waste

management claims – i.e. reduced actinide mass and total

radiotoxicity beyond 300 years – are insufficient to critically

assess the short- and long-term safety, economics, and

proliferation resistance of the proposed fuel cycles.

“Furthermore, the promised (albeit irrelevant) actinide

reductions are only attainable given exceptional

technological requirements, including commercial-scale

spent fuel treatment, reprocessing, and conditioning

facilities. These will create low- and intermediate-level

waste streams destined for geologic disposal, in addition

to the intrinsic high-level fission product waste that will

also require conditioning and disposal.


“Before construction of non-traditional reactors begins,

the economic implications of the back end of these nontraditional

fuel cycles must be analyzed in detail; disposal

costs may be unpalatable. The reprocessing/treatment

and conditioning of the spent fuel will entail costs, as will

storage and transportation of the chemically reactive fuels.

These are in addition to the cost of managing high-activity

operational wastes, e.g. those originating from molten

salt reactor filter systems. Finally, decommissioning the

reactors and processing their chemically reactive coolants

represents a substantial undertaking and another source

of non-traditional waste. …

“Issues of spent fuel management (beyond temporary

storage in cooling pools, aka “wet storage”) fall outside

the scope of the NRC’s reactor design certification

process, which is regularly denounced by nuclear

advocates as narrowly applicable to light water reactor

technology and insufficiently responsive to new reactor

designs. Nevertheless, new reactor licensing is contingent

on broader policies, including the Nuclear Waste Policy

Act and the Continued Storage Rule. Those policies are

based on the results of radionuclide dispersion models

described in environmental impact statements. But the

fuel and barrier degradation mechanisms tested in these

models were specific to oxide-based spent fuels, which

are inert, compared to the compounds that non-traditional

reactors will discharge.


“The Continued Storage Rule explicitly excludes most

non-oxide fuels, including those from sodium-cooled fast

reactors, from the environmental impact statement. Clearly,

storage and disposal of non-oxide commercial fuels should

require updated assessments and adjudication.

“Finally, treatment of spent fuels from non-traditional

reactors, which by Energy Department precedent is

only feasible through their respective (re)processing

technologies, raises concerns over proliferation and fissile

material diversion. Pyroprocessing and fluoride volatilityreductive

extraction systems optimized for spent fuel

treatment can – through minor changes to the chemical

conditions – also extract plutonium (or uranium 233 bred

from thorium). Separation from lethal fission products

would eliminate the radiological barriers protecting the

fuel from intruders seeking to obtain and purify fissile

material. Accordingly, cost and risk assessments of

predisposal spent fuel treatments must also account for

proliferation safeguards.


“Radioactive waste cannot be “burned”; fission of

actinides, the source of nuclear heat, inevitably generates

fission products. Since some of these will be radiotoxic

for thousands of years, these high-level wastes should

be disposed of in stable waste forms and geologic

repositories. But the waste estimates propagated by

nuclear advocates account only for the bare mass of

fission products, rather than that of the conditioned waste

form and associated repository requirements.

“These estimates further assume that the efficiency

of actinide fission will surge, but this actually relies on

several rounds of recycling using immature reprocessing

technologies. The low- and intermediate-level wastes

that will be generated by these activities will also be

destined for geologic disposal but have been neglected

in the waste estimates. More important, reprocessing

remains a security liability of dubious economic benefit,

so the apparent need to adopt these technologies simply

to prepare non-traditional spent fuels for storage and

disposal is a major disadvantage relative to light water

reactors. Theoretical burnups for fast and molten salt

reactors are too low to justify the inflated back-end costs

and risks, the latter of which may include a commercial

path to proliferation.


“Reductions in spent fuel volume, longevity, and total

radiotoxicity may be realized by breeding and burning

fissile material in non-traditional reactors. But those

relatively small reductions are of little value in repository

planning, so utilization of these metrics is misleading to

policy-makers and the general public. We urge policymakers

to critically assess non-traditional fuel cycles,

including the feasibility of managing their unusual waste

streams, any loopholes that could commit the American

public to financing quasi-reprocessing operations, and

the motivation to rapidly deploy these technologies. If

decarbonization of the economy by 2050 is the end-goal,

a more pragmatic path to success involves improvements

to light water reactor technologies, adoption of Blue

Ribbon Commission recommendations on spent fuel

management, and strong incentives for commercially

mature, carbon-free energy technologies.”

Lindsay Krall and Allison Macfarlane, 2018, ‘Burning

waste or playing with fire? Waste management

considerations for non-traditional reactors’, Bulletin of the

Atomic Scientists, 74:5, pp.326-334, https://tandfonline.


Molten salt reactors and sodium-cooled fast reactors make the radioactive waste problem WORSE

October 9, 2018
Burning waste or playing with fire? Waste management considerations for non-traditional reactors, Lindsay Krall &Allison Macfarlane, 31 Aug 18


Nuclear energy-producing nations are almost universally experiencing delays in the commissioning of the geologic repositories needed for the long-term isolation of spent fuel and other high-level wastes from the human environment. Despite these problems, expert panels have repeatedly determined that geologic disposal is necessary, regardless of whether advanced reactors to support a “closed” nuclear fuel cycle become available. Still, advanced reactor developers are receiving substantial funding on the pretense that extraordinary waste management benefits can be reaped through adoption of these technologies. 

Here, the authors describe why molten salt reactors and sodium-cooled fast reactors – due to the unusual chemical compositions of their fuels – will actually exacerbate spent fuel storage and disposal issues. Before these reactors are licensed, policymakers must determine the implications of metal- and salt-based fuels vis a vis the Nuclear Waste Policy Act and the Continued Storage Rule.

Terra Power’s Traveling Wave Nuclear Reactor sounds great – BUT!

October 9, 2018

TerraPower’s Nuclear Reactor Could Power the 21st Century. The traveling-wave reactor and other advanced reactor designs could solve our fossil fuel dependency IEEE Spectrum, By Michael Koziol  3 June 18,    “….  ..In a world defined by climate change, many experts hope that the electricity grid of the future will be powered entirely by solar, wind, and hydropower. Yet few expect that clean energy grid to manifest soon enough to bring about significant cuts in greenhouse gases within the next few decades. Solar- and wind-generated electricity are growing faster than any other category; nevertheless, together they accounted for less than 2 percent of the world’s primary energy consumption in 2015, according to the Renewable Energy Policy Network for the 21st Century.

Vain hopes for Small Modular Nuclear Reactors (SMRs) – expensive and there are no customers anyway

April 2, 2018

Small Modular Reactors for Nuclear Power: Hope or Mirage?   by M.V. Ramana 

Supporters of nuclear power hope that small nuclear reactors, unlike large  plants, will be able to compete economically with other sources of electricity. But according to M.V. Ramana, a Professor at the University of British Columbia, this is likely to be a vain hope. In fact, according to Ramana, in the absence of a mass market, they may be even more expensive than large plants.

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

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

In the past decade, wind and solar energy have become significantly cheaper than nuclear power

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

Still expensive

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

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

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

“The problem I have with SMRs is not the technology, it’s not the deployment ‒ it’s that there’s no customers”

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

Ahead of the market

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

There is a further hurdle to be overcome before these large numbers of SMRs can be built. For a company to invest
in a factory to manufacture reactors, it would have to be confident that there is a market for them. This has not been the case and hence no company has invested large sums of its own money to commercialize SMRs.

An example is the Westinghouse Electric Company, which worked on two SMR designs, and tried to get funding from the US Department of Energy (DOE). When it failed in that effort, Westinghouse stopped working on SMRs and decided to focus its efforts on marketing the AP1000 reactor and the decommissioning business. Explaining this decision, Danny Roderick, then president and CEO of Westinghouse, announced: “The problem I have with SMRs is not the technology, it’s not the deployment ‒ it’s that there’s no customers. … The worst thing to do is get ahead of the market”.

Delayed commercialization

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

There are simply not enough remote communities, with adequate purchasing capacity, to be able to make it financially viable to manufacture SMRs by the thousands

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

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

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

No real market demand

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

Neither nuclear reactor companies, 
nor any governments that back nuclear power, are willing to spend the hundreds of millions, if not a few billions, of dollars to set up SMRs just so that these small and remote communities will have nuclear electricity

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

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

Editor’s note:

Prof. M. V. Ramana is Simons Chair in Disarmament, Global and Human Security at the Liu Institute for Global Issues, as part of the School of Public Policy and Global Affairs at the University of British Columbia, Vancouver.  This article was first published in National University of Singapore Energy Studies Institute Bulletin, Vol.10, Issue 6, Dec. 2017, and is republished here with permission.

Some of the problems with thorium nuclear reactors

April 2, 2018

Disadvantages of thorium reactors:  High start-up costs: Huge investments are needed for thorium nuclear power reactor, as it requires significant amount of testing, analysis and licensing work. Also, there is uncertainty over returns on the investments in these reactors. For utilities, this factor can weigh on the decisions to go ahead with plans to deploy the reactors. The reactors also involve high fuel fabrication and reprocessing costs.

High melting point of thorium oxide: As melting point of thorium oxide is much higher compared to that of uranium oxide, high temperatures are needed to make high density ThO2 and ThO2–based mixed oxide fuels. The fuel in nuclear fission reactors is usually based on the metal oxide.

Emission of gamma rays: Presence of Uranium-232 in irradiated thorium or thorium based fuels in large amounts is one of the major disadvantages of thorium nuclear power reactors. It can result in significant emissions of gamma rays.

The fantasy of Small Modular Nuclear Reactors for outback Australia

April 2, 2018

Volunteers wanted – to house small modular nuclear reactors in Australia,Online Opinion, Noel WAuchope , 11 Dec 17, 

We knew that the Australian government was looking for volunteers in outback South Australia, to take the radioactive trash from Lucas Heights and some other sites, (and not having an easy time of it). But oh dear– we had no idea that the search for hosting new (untested) nuclear reactors was on too!

Well, The Australian newspaper has just revealed this extraordinary news, in its article “Want a nuclear reactor in your backyard? Step this way” (28/11/17). Yes, it turns out that a Sydney-based company, SMR Nuclear Technology, plans to secure volunteers and a definite site within three years. If all goes well, Australia’s Small Modular Reactors will be in operation by 2030.

Only, there are obstacles. Even this enthusiastic article does acknowledge one or two of them. One is the need to get public acceptance of these so far non-existent new nuclear reactors. SMR director Robert Pritchard is quoted as saying that interest in these reactors is widespread. He gives no evidence for this.

The other is that the construction and operation of a nuclear power plant in Australia is prohibited by both commonwealth and state laws.

But there are issues, and other obstacles that are not addressed on this article. A vital question is: does SMR Nuclear Technology intend to actually build the small reactors in Australia, or more likely, merely assemble them from imported modular parts – a sort of nuclear Lego style operation?

If it is to be the latter, there will surely be a delay of probably decades. Development of SMRs is stalled, in USA due to strict safety regulations, and in UK, due to uncertainties, especially the need for public subsidy. That leaves China, where the nuclear industry is government funded, and even there, development of SMRs is still in its infancy.

As to the former, it is highly improbable that an Australian company would have the necessary expertise, resources, and funding, to design and manufacture nuclear reactors of any size. The overseas companies now planning small reactors are basing their whole enterprise on the export market. Indeed, the whole plan for “modular” nuclear reactors is about mass production and mass marketing of SMRs -to be assembled in overseas countries. That is accepted as the only way for the SMR industry to be commercially successful. Australia looks like a desirable customer for the Chinese industry, the only one that looks as if it might go ahead, at present,

If, somehow, the SMR Technologies’ plan is to go ahead, the other obstacles remain.

The critical one is of course economics. …….

Other issues of costs and safety concern the transport of radioactive fuels to the reactors, and of radioactive waste management. The nuclear industry is very fond of proclaiming that wastes from small thorium reactors would need safe disposal and guarding for “only 300 years”. Just the bare 300!

The Australian Senate is currently debating a Bill introduced by Cory Bernardi, to remove Australia’s laws prohibiting nuclear power development. The case put by SMR Technologies, as presented in The Australian newspaper is completely inadequate. The public deserves a better examination of this plan for Small Modular Reactors SMRS. And why do they leave out the operative word “Nuclear” -because it is so on the nose with the public?

Edwin Lyman on Small Modular Reactors

November 29, 2017

Small Isn’t Always Beautiful Safety, Security, and Cost Concerns about Small Modular Reactors

UCS, Edwin Lyman September 2013

“…….Less expensive does not necessarily mean cost effective, however. The safety of the proposed compact designs is unproven—for instance, most of the designs call for weaker containment structures. And the arguments in favor of lower overall costs for SMRs depend on convincing the Nuclear Regulatory Commission to relax existing safety regulations………

Congress should direct the Department of Energy (DOE) to spend taxpayer money only on support of technologies that have the potential to provide significantly greater levels of safety and security than currently operating reactors. The DOE should not be promoting the idea that SMRs do not require 10-mile emergency planning zones—nor should it be encouraging the NRC to weaken its other requirements just to facilitate SMR licensing and deployment………

“Small” is defined by the DOE as one that generates less than 300 MWe (megawatts of electric power), which is about 30 percent of the capacity of a typical current commercialpower reactor. “Modular” refers to the concept that the units would be small enough to be manufactured in factories and shipped to reactor sites as needed to meet incremental increases in demand (Smith-Kevern)……….

… greater levels of nuclear plant safety and security cannot be achieved by smart design alone. It must also extend to operation. Without an overarching regulatory framework focused on substantially increasing the level of operational safety, there will be no assurance of greater safety for next-generation reactors either large or small…….

“Affordable” doesn’t necessarily mean “cost-effective.”…….

.. far from increasing design and operational safety standards, proponents of SMRs claim small modular reactors will be so much safer than large reactors that they will not need to meet the same safety standards as large reactors, arguing that they need far fewer operators and security officers, and that they can have disproportionately smaller and weaker containment buildings. SMR advocates claim that they are so safe they can be located close to densely populated areas without the need for extensive evacuation planning. This argument is a crucial part of the case being made by the DOE and others that SMRs can be deployed to replace coal plants at existing sites, many of which are near urban areas. We consider each of those issues below.

“affordable” doesn’t necessarily mean “cost-effective.” According to basic economic principles, the cost per kilowatt-hour of the electricity produced by a small reactor will be higher than that of a large reactor, all other factors being equal. That is because SMRs are penalized by the economies of scale of larger reactors—a principle that drove the past industry trend to build larger and larger plants (Shropshire). For example, a 1,100 MWe plant would cost only about three times as much to build as a 180 MWe version, but would generate six times the power, so the capital cost per kilowatt would be twice as great for the smaller plant (see, e.g., the economies of scale formula used by Carelli et al.)

SMR proponents argue that other factors could offset this difference, effectively reversing the economies of scale. For example, efficiencies associated with the economics of mass production could lower costs if SMRs are eventually built and sold in large numbers. Such factors are speculative at this point, however, and the degree to which they might reduce costs has not been well characterized. A 2011 study found that even taking into account all the factors that could offset economies of scale, replacement of one 1,340 MWe reactor with four 335 MWe units would still increase the capital cost by 5 percent (Shropshire).

The potential cost benefits of assembly-line module construction relative to custom-built on-site construction may also be overstated. Moreover, mistakes on a production line can lead to generic defects that could propagate through an entire fleet of reactors and be costly to fix. The experience to date with construction of modular parts for the nuclear industry has been troubling……..

….Unless the negative economies of scale can be overcome, SMRs could well become affordable luxuries: more utilities may be in a financial position to buy an SMR without “betting the farm,” but still lose money by producing high-cost electricity. In any event, it would take many years of industrial experience, and the production of many units, before the potential for manufacturing cost savings could be demonstrated. In the meantime, as the Secretary of Energy Advisory Board’s SMR subcommittee stated in a November 2012 report, “first of a kind costs in U.S. practice will likely make the early [SMR] units considerably more expensive than alternative sources of power. If the U.S. is to create a potential SMR market for US vendors, it will need to do something to help out with such costs” (SEAB). The report pointed out that if the government decided to provide such help, it would have a “panoply of direct and indirect tools available to support the development of an SMR industry” ranging from “funding SMR demonstration plants, perhaps on U.S. government sites (the DOE is a particularly large user of electricity) to a variety of financial incentives” including “continued cost sharing with selected SMR vendors beyond design certification,” “loan guarantees,” and “production tax credits or feed-in tariffs for those utility generators that are early users of SMR power purchase contracts.”…….

DOE officials have referred to this situation as a “Catch-22.” The economics of mass production of SMRs cannot be proven until hundreds of units have been produced. But that can’t happen unless there are hundreds of orders, and there will be few takers unless the price can be brought down. This is why the industry believes significant government assistance would be needed to get an SMR industry off the ground.

In addition, there appears to be a growing realization that the first SMR production factory cannot fill its order book with domestic units but will need to access a sizable international export market………

In addition to imposing a penalty on the capital cost of SMRs, economies of scale would also negatively affect operations and maintenance (O&M) costs (excluding costs for nuclear fuel, which scale proportionately with capacity). Labor costs are a significant fraction of nuclear plant O&M costs, and they do not typically scale linearly with the capacity of the plant: after all, a minimum number of personnel are required to maintain safety and security regardless of the size……..

SMR vendors are pressuring the NRC to weaken regulatory requirements for SMRs……. . Unless utilities can find a way to justify significantly reducing personnel for smaller reactors, SMRs will need a larger number of workers to generate a kilowatt of electricity than large reactors. Yet a 2011 study of 50 small and medium-sized reactors in Europe concluded that O&M costs must be kept consistently “low”—defined as less than 20 percent of total costs—to maintain SMR cost competitiveness (Shropshire). To reduce both capital costs and O&M costs, SMR vendors are pressuring the NRC to weaken certain regulatory requirements for SMRs……..

SMR Designs……….

NuScale. The NuScale concept is considerably different from both the mPower SMR design as well as from the current fleet of large nuclear reactors. The NuScale design envisions an array of up to 12 reactor modules, each generating 45 MWe of power, submerged under water in a swimming-pool-like structure. Each module would be 65 feet tall and nine feet in diameter, and would be nested within a very small containment structure 82 feet tall and 15 feet in diameter. Unlike the mPower design, the NuScale control rod drive mechanisms would be external to the vessel. Only natural convection cooling of the core would be used both for routine operation and for emergencies: there would be no coolant pumps at all in the primary reactor coolant system (the primary cooling system carries heat from the core to the steam generators). The secondary loop, the system that carries steam from the steam generators to the turbines, would still require motor-driven pumps. NuScale differs from other pressurized water reactors in that the primary coolant is not pumped through the steam generators, but flows around outside of them. The secondary coolant is pumped through the steam generator coils. The designers claim that emergency cooling could be maintained indefinitely in a station blackout by relying on a series of valves that do not require electrical power to open or close and achieve their correct positions (Neve).

Holtec SMR-160. The Holtec SMR-160 will generate 160 MWe. Like the NuScale, it is designed for passive cooling of the primary system during both normal and accident conditions. However, the modules would be much taller than the NuScale modules and would not be submerged in a pool of water. Each reactor vessel would be located deep underground, with a large inventory of water above it that could be used to provide a passive heat sink for cooling the core in the event of an accident. Each containment building would be surrounded by an additional enclosure for safety, and the space between the two structures would be filled with water. Unlike the other iPWRs, the SMR-160 steam generators are not internal to the reactor vessel. The reactor system is tall and narrow to maximize the rate of natural convective flow, which is low in other passive designs. Holtec has not made precise dimensions available, but the reactor vessel is approximately 100 feet tall, and the aboveground portion of the containment is about 100 feet tall and 50 feet in diameter (Singh 2013)

For these and other SMRs, it is important to note that only limited information is available about the design, as well as about safety and security. A vast amount of information is considered commercially sensitive or security-related and is being withheld from the public. ……

SMR Safety In general, the engineering challenges of ensuring safety in small modular reactors are not qualitatively different from those of large reactors. No matter the size, there must be systems in place to ensure that the heat generated by the reactor core is removed both under normal and accident conditions at a rate sufficient to keep the fuel from overheating, becoming damaged, and releasing radioactivity. The effectiveness of such systems depends on the details of their design. Even nuclear fuel in spent fuel pools, which usually have much lower heat loads than reactor cores, can overheat and rupture if adequate cooling is not provided……..

……some vendors are marketing these designs as “inherently safe,” which is a misleading term. While there is no question that natural circulation cooling could be effective under many conditions for such small reactors, it is not the case that these reactors would be inherently safe under all accident conditions. There are accident scenarios in which heat-transfer conditions would be less than ideal and thus natural convection cooling could be impeded. For instance, for the NuScale design a large earthquake could send concrete debris into the pool, obstructing circulation of water or air. Indeed, no credible reactor design is completely passive: no design can shut itself down and cool itself in every circumstance without the need for intervention. Even passively safe reactors require some equipment, such as valves, that are designed to operate automatically. But no valve is 100 percent reliable. In addition, as discussed below, accidents affecting more than one small unit may cause complications that could overwhelm the capacity to cope with multiple failures, outweighing the advantages of having lower heat removal requirements per unit.

Ultimately, how well any safety systems work depends on the accidents against which they are designed to protect. Passive systems alone can address only a limited range of scenarios, and may not work as intended in the event of beyond-design-basis accidents. As a result, passive designs should also be equipped with multiple, diverse, and highly reliable active backup cooling systems. Such systems will necessarily be more complex but the engineering challenges should be manageable with good design of instrumentation and control system architecture. Still, more backup systems generally mean higher costs. Thus, a multiple-backup design philosophy is not generally compatible with the small, compact, stripped-down design of the SMRs currently under consideration………

The need to reduce SMR capital costs is driving one important passive safety system—the containment structure—to be smaller and less robust. None of the iPWR designs has a containment structure around the reactor with sufficient strength and volume to withstand the forces generated by overpressurization and hydrogen explosions in severe accidents. SMRs therefore must rely on means to prevent hydrogen from reaching explosive concentrations. However, neither active means (hydrogen igniters) nor passive means (hydrogen recombiners) of hydrogen control are likely to be as reliable as a robust containment………

Some SMR vendors propose to locate their reactors underground, which they argue will be a major safety benefit. While underground siting would enhance protection against certain events, such as aircraft attacks and earthquakes, it could have disadvantages as well. Again at Fukushima Daiichi, emergency diesel generators and electrical switchgear were installed below grade to reduce their vulnerability to seismic events, but that location increased their susceptibility to flooding. Moreover, in the event of a serious accident, emergency crews could have greater difficulty accessing underground reactors.

Underground siting of reactors is not a new idea. Decades ago, both Edward Teller and Andrei Sakharov proposed siting reactors deep underground to enhance safety. However, it was recognized early on that building reactors underground increases cost. Numerous studies conducted in the 1970s found construction cost penalties for underground reactor construction ranging from 11 to 60 percent (Myers and Elkins). As a result, the industry lost interest in underground siting. This issue will require considerable analysis to evaluate trade-offs.

And if it proves to be advantageous to safety, it remains to be seen whether reactor owners will be willing to pay for the additional cost of underground siting.

Complications of Multiple Reactors at a Site

SMR proponents frequently claim that, like the next generation of large reactors, the probability of reactor core damage can be lower for SMRs than for currently operating reactors. Although true, it is important to note that such claims refer to frequencies of internal events such as pipe breaks. When external events such as earthquakes, floods, and fires are added to a probabilistic risk assessment, however, the Nuclear Energy Institute (NEI)—the policy organization of the nuclear industry—has pointed out that, “the calculated risk metrics for new reactors are likely to increase and therefore be closer to current plants than being portrayed today” (NEI)………..

SMR proponents also point out that the risk to the public from small reactors is lower than that from large reactors, by virtue of the fact that there is less radioactive material in the core. While that is certainly true, it is not the most useful comparison. The relevant factor with regard to societal risk is not the risk per unit, but the risk per megawatt of electricity generated. By this measure, small reactors do not necessarily imply smaller risks if there are more of them.

To see why, consider the impact on risk if one large unit is replaced with multiple smaller units providing the same total power. If the probability of core damage is comparable for small reactors and large reactors, then the total site risk—the probability of an accident multiplied by its consequence—will also be comparable in both cases (see Figure 1). Indeed, the overall site risk for the multiple SMRs could actually be higher than for a single reactor.

The scenario in Figure 1 assumes the damage probabilities and the consequences for the multiple reactors are independent. But they will not be independent unless the potential for common-mode failures and interactions between the multiple reactors are fully addressed.

In order for individual reactor units to remain independent, the number of support staff and amount of safety equipment would need to increase with the number of units on a site. Only through significant sharing of systems and personnel by multiple units, however, could the associated cost increase be moderated. Thus, the SMR vendors want to reduce the number of control rooms and licensed operators that the NRC would ordinarily require for a certain number of units. For example, the NuScale design could have a single control room operator in charge of as many as 12 units, the feasibility of which would have to be verified through performance testing……….

Distribution of SMRs Some SMR proponents argue that the size and safety of the designs of small modular reactors make them well suited for deployment to remote areas, military bases, and countries in the developing world that have small electric grids, relatively low electric demand, and no nuclear experience or emergency planning infrastructure. Such deployments, however, would raise additional safety, security, and proliferation concerns.

First, building many small reactors at a large number of geographically dispersed sites would put great strains on resources for licensing and for safety and security inspections……

Second, deployment of individual small reactors at widely distributed sites around the world could strain the resources of the International Atomic Energy Agency (IAEA) because inspectors would need to visit more locations per installed megawatt around the world. That strain could degrade the IAEA’s ability to safeguard reactors against their misuse for covert nuclear weapon programs. Maintaining robust oversight over vast networks of SMRs around the world would not only be difficult, but also would require the international community to increase funding significantly for the IAEA—a task that has already been extremely difficult to achieve in recent decades.

Third, it is unrealistic to assume that SMRs—especially in the near term—will be so safe that they can be shipped around the world without the need to ensure the highest levels of competence and integrity of local regulatory authorities, plant operators, emergency planning organizations, and security forces. Indeed, many nations where the DOE hopes to export SMRs may not have the resources to safely operate nuclear power plants………

Regulatory Rollbacks The SMR vendors are vigorously seeking regulatory relief from the NRC that would allow them to meet weaker safety and security standards. Such relief would not necessarily involve actual changes to the NRC’s regulations, but could be achieved through a variety of other mechanisms within the existing regulatory framework.

Security of SMRs

The pressure cooker bombs that exploded at the Boston Marathon on April 15, 2013, were a stark reminder of the ongoing terrorist threat in the United States. Nuclear reactors, like all elements of critical infrastructure, must be prepared to withstand terrorist attacks. Fukushima Daiichi demonstrated how rapidly a nuclear reactor accident can progress to a core meltdown if multiple safety systems are disabled. A well-planned and -executed terrorist attack could cause damage comparable to or even worse than the earthquake and tsunami that initiated the Fukushima crisis, potentially in even less time. For these reasons, the NRC requires nuclear plant owners to implement robust security programs to protect their plants against sabotage.

Despite these concerns, SMR proponents argue for reducing security requirements—in particular, security staffing—to reduce the cost of electricity produced by small modular reactors.

In 2011, Christofer Mowry, president of Babcock & Wilcox mPower, Inc., said, “Whether SMRs get deployed in large numbers or not is going to come down to O&M [operations and maintenance]. And the biggest variable that we can attack directly, the single biggest one, is the security issue” (NRC 2011a). His position was echoed by the NEI, which submitted a position paper to the NRC in July 2012 on the issue of physical security for SMRs (NEI 2012). It clearly laid out the industry view:

The regulatory issue of primary importance related to physical security of SMRs is security staffing. The issue has the potential to adversely affect the viability of SMR development in the U.S. Security staffing directly impacts annual operations and maintenance (O&M) costs and as such constitutes a significant financial burden over the life of the facility.  For this reason, evaluation of security staffing requirements for SMRs has become a key focal point.

The paper goes on to say:

[NRC security] requirements, many of which are based on years of operating experience with large LWR [light-water reactor] facilities, may not be appropriate or necessary for SMRs due to the[ir] simpler, safer and more automated design characteristics .

The NRC requires that nuclear power reactors protect against the design-basis threat (DBT) of radiological sabotage. That requirement mandates that armed response forces be deployed round-the-clock at reactors, charged with the sole responsibility for preventing a group of attackers with paramilitary training and weapons from destroying enough plant equipment to result in damage to the reactor core or spent fuel……..

The nuclear industry’s preoccupation with reducing security staffing is somewhat surprising. Even though security labor costs are significant, they are far from being a dominant contributor to overall O&M costs. Security staffing costs range from 15 to 25 percent of total O&M costs.

Reducing the security force at nuclear reactors would appear to be pennywise but pound-foolish……..

one thing is clear: a well-planned terrorist attack could indeed cause the kind of large-break loss-of-coolant event that the plant’s designers say could not occur in a mere accident. If terrorists were able to access the reactor vessel—a feat more likely with reduced security staffing—they could blow a hole in it in short order, utilizing the explosives that are assumed to be within the design-basis threat……….

The primary feature that mPower and other SMR vendors appear to credit in seeking relief from security regulations is underground siting. Underground siting would enhance protection against some attack scenarios, but not all. A direct jet impact on the reactor containment is less likely for an underground reactor, but the ensuing explosions and fire could cause a crisis. Certain systems, such as steam turbines, condensers, electrical switchyards, and cooling towers, will need to remain aboveground, where they will be vulnerable. Plants will require adequate access and egress for both routine and emergency personnel. Ventilation shafts and portals for equipment access also provide potential means of entry for intruders. In addition, if SMR sites have smaller footprints, as vendors are claiming, the site boundary will be closer to the reactor, and thus there will be less warning time in the event of an intrusion and potentially insufficient spatial separation of redundant and diverse safety systems.

In short, knowledgeable and determined adversaries will likely be able to develop attack scenarios that could circumvent measures such as underground siting. In situations such as hostage scenarios, terrorists may even be able to utilize the additional defense afforded by an underground site against off-site police and emergency response. Thus, a robust and flexible operational security response will be required no matter what intrinsic safeguards are added to reactor design……

Conclusions Unless a number of optimistic assumptions are realized, SMRs are not likely to be a viable solution to the economic and safety problems faced by nuclear power.

Indeed, SMRs are likely to have challenges keeping electricity costs low enough to be economically competitive with other sources, including larger reactors. As a result, concerns about costs and competitiveness may drive companies to make decisions about the design and operation of SMRs that undermine any new, inherent safety features not present in current large reactors. For example, designers may reduce other safety features, such as reducing containment strength or the diversity and redundancy of safety systems. Or the NRC may allow SMR owners to reduce the sizes of emergency planning zones and the numbers of operators and security officers per reactor…….


Scrutiny on James Hansen’s Generation IV nuclear fallacies and fantasies

October 30, 2017

James Hansen’s Generation IV nuclear fallacies and fantasies, REneweconomy, Jim Green, 28 Aug 2017

The two young co-founders of nuclear engineering start-up Transatomic Power were embarrassed earlier this year when their claims about their molten salt reactor design were debunked, forcing some major retractions.

The claims of MIT nuclear engineering graduates Leslie Dewan and Mark Massie were trumpeted in MIT’s Technology Review under the headline, ‘What if we could build a nuclear reactor that costs half as much, consumes nuclear waste, and will never melt down?’

MIT physics professor Kord Smith debunked a number of Transatomic’s key claims. Smith says he asked Transatomic to run a test which, he says, confirmed that “their claims were completely untrue.”

Kennedy Maize wrote about Transatomic’s troubles in Power Magazine: “[T]his was another case of technology hubris, an all-to-common malady in energy, where hyperbolic claims are frequent and technology journalists all too credulous.” Pro-nuclear commentator Dan Yurman said that “other start-ups with audacious claims are likely to receive similar levels of scrutiny” and that it “may have the effect of putting other nuclear energy entrepreneurs on notice that they too may get the same enhanced levels of analysis of their claims.”

Well, yes, others making false claims about Generation IV reactor concepts might receive similar levels of scrutiny … or they might not. Arguably the greatest sin of the Transatomic founders was not that they inadvertently made false claims, but that they are young, and in Dewan’s case, female. Ageing men seem to have a free pass to peddle as much misinformation as they like without the public shaming that the Transatomic founders have been subjected to. A case in point is climate scientist James Hansen ‒ you’d struggle to find any critical commentary of his nuclear misinformation outside the environmental and anti-nuclear literature.

Hansen states that 115 new reactor start-ups would be required each year to 2050 to replace fossil fuel electricity generation ‒ a total of about 4,000 reactors. Let’s assume that Generation IV reactors do the heavy lifting, and let’s generously assume that mass production of Generation IV reactors begins in 2030. That would necessitate about 200 reactor start-ups per year from 2030 to 2050 ‒ or four every week. Good luck with that.

Moreover, the assumption that mass production of Generation IV reactors might begin in or around 2030 is unrealistic. A report by a French government authority, the Institute for Radiological Protection and Nuclear Safety, states: “There is still much R&D to be done to develop the Generation IV nuclear reactors, as well as for the fuel cycle and the associated waste management which depends on the system chosen.”

Likewise, a US Government Accountability Office report on the status of small modular reactors (SMRs) and other ‘advanced’ reactor concepts in the US concluded: “Both light water SMRs and advanced reactors face additional challenges related to the time, cost, and uncertainty associated with developing, certifying or licensing, and deploying new reactor technology, with advanced reactor designs generally facing greater challenges than light water SMR designs. It is a multi-decade process …”

An analysis recently published in the peer-reviewed literature found that the US government has wasted billions of dollars on Generation IV R&D with little to show for it. Lead researcher Dr Ahmed Abdulla, from the University of California, said that “despite repeated commitments to non-light water reactors, and substantial investments … (more than $2 billion of public money), no such design is remotely ready for deployment today.”……

Australian Greens REJECT Australia joining Generation IV Nuclear Energy Accession

July 24, 2017
Dissenting Report – Australian Greens, Senator Sarah Hanson-Young Australian Greens Senator, 
While not always supporting the outcomes, the Australian Greens have acknowledged previous JSCOT inquiries on nuclear issues for their diligence and prudence. We are disappointed on this occasion to submit a dissenting report into the Generation IV Nuclear Energy Accession. The inquiry process into the Framework Agreement for International Collaboration on Research and Development of Generation IV Nuclear Energy Systems has been unduly rushed and lacked adequate public hearings or detailed analysis and reflection of public submissions. This is particularly disturbing given that this inquiry relates to public spending for an undefined period of time towards a technology that is prohibited in Australia.
The Australian Greens’ dissent to Report 171 (Section 4: Generation IV Nuclear Energy Accession) is based on a range of grounds, including:
The lack of transparency regarding the costs to the Australian taxpayer over an undefined period of time;
The technology that this agreement relates to is prohibited under Australian law and its promotion is inconsistent with the public and national interest;
The lack of consideration of the global energy trends away from nuclear technology;
The lack of procedural fairness in refusing adequate public hearings and consideration of public submissions;
An unjustified reliance on the submissions from the highly partisan Australian Nuclear Science and Technology Organisation (ANSTO). The Australian Greens note that ANSTO is not a disinterested party in this policy arena. Furthermore, ANSTO has made a number of unfounded assertions, particularly regarding the Agreement’s impact on Australia’s standing on nuclear non-proliferation.

Unchecked capacity and resourcing

The timeframe for the agreement is loosely stated as being between 10 and 40 years. Over this period there is a commitment for Australia to pledge resources and capacity at the expense of Australian taxpayers. In exchange for this undefined public expense for an undefined period of time, there is no clear public benefit – given that the technology is, properly and popularly, prohibited in this country.
Point 4.20 states that the Framework is in essence about spreading the significant costs associated with the development of Generation IV reactors. In public submissions made to JSCOT there are detailed cost estimates for individual projects that are all in the range of billions of dollars. There have been numerous delays, cost constraints and problems with the various types of reactors described as Generation IV. While some countries continue to pursue this technology, there is no clear end-game in sight and many nations are stepping away from this sector. Most Generation IV reactors only exist on paper while some others are modified plans of expensive failed projects but are still just conceptual.
It is understandable that countries who are invested in Generation IV would seek to transfer costs and inflate the potential benefits. It is unreasonable, however, for a Government agency to commit Australian resources to fund and develop this technology which is decades away from being anything more than a concept.
ANSTO submits in the National Interest Analysis that the “costs of participation in the Systems Arrangements will be borne by ANSTO from existing funds”. The Australian Greens note that in the last financial year ANSTO reported a loss of $200 million (including $156 million in subsidies). The commitment of funds and resourcing from an agency that operates with an existing deficit that is already funded by the Australian people is fiscally irresponsible and has not been investigated through the JSCOT process.
The Australian Greens maintain that there is a particular need for the rationale of any contested public expenditure to be rigorously tested. Sadly, this Committee has failed in this role.
Point 4.24 of the report states that “Australia was required to demonstrate that it could contribute to the research and development goals of the GIF” yet the inquiry process failed to establish exactly what form those contributions will take and the cost of those contributions to the Australian people.

Prohibited Technology

Point 4.39 on the question of nuclear power in Australia brushes aside the fundamental issue that the future of nuclear energy in Australia is entirely dependent on changing Commonwealth laws.
Report 171 section 4 fails to acknowledge that the technology in question is prohibited under two separate pieces of Commonwealth legislation:
Section 37J of the Environmental Protection and Biodiversity Conservation Act 1999;
Section 10 of the Australian Radiation Protection and Nuclear Safety Act 1998.
These Acts reflect considered positions, public opinion and the environmental and economic risk associated with nuclear technology which has repeatedly proved to be dangerous and expensive. The position reflected in these laws has been repeatedly reiterated in subsequent Government reports into the technology and prospects for development in Australia. For example:
The Switkowski Report – Uranium Mining, Processing, and Nuclear Energy – opportunities for Australia? (2006)
The Australian Power Generation Technology Report – Summary (Nov 2015)
Department of Energy and Science Energy White Paper (2015)
Nuclear Fuel Cycle Royal Commission (South Australia) (May 2016)
These reports all arrive at the same conclusion: that there is no case to develop nuclear power in Australia, albeit for different reasons. These reasons include costs, time constraints, legal constraints, public opposition, restrictions on availability of water and other environmental factors.

Lack of Procedural Fairness and over reliance on evidence from ANSTO

ANSTO has pursued this agreement, signed the agreement, will be responsible for enacting the agreement, drove the National Interest Analysis and were the only agency invited to present at a hearing. This agency is publicly funded, has run at a deficit, and is seeking to further commit Australian resources to a technology that is not only unpopular but is prohibited under Australian legislation.
There is a wide range of experts and public interest groups who have lodged detailed submissions and requested an audience with the Committee to offer some scrutiny and balance to the highly selective view of Generation IV options presented by ANSTO.
These submissions are barely mentioned in Report 171 and additional public hearings were denied. This level secrecy and denial of procedural fairness is of grave concern and, while out of character for JSCOT, is very much in line with the secrecy synonymous with ANSTO and the wider nuclear industry.

Australia’s accessibility to nuclear technology and standing on nuclear non-proliferation

ANSTO claim in the NIA that a failure to accede “would impede Australia’s ability to remain constructively engaged in international nuclear activities and would limit our ability to forge links with international experts at a time when a significant expansion in nuclear power production is underway……. It would diminish Australia’s standing in international nuclear non-proliferation and our ability to influence international nuclear policy developments in accordance with our national economic and security interests.”
The Australian Greens understand that Australia currently pays $10 million per annum to the International Atomic Energy Agency which grants us access to the safety and regulatory fora and to publicly published research. Where there is a commercial interest in the technology this would no doubt be made available to Australia at a price – but a price not borne by the taxpayer in this crude subsidy by stealth proposed in report 171 (Section 4).
Claims that our failure to accede would somehow diminish our standing on nuclear non-proliferation are absurd. While the industry might promote Generation IV as addressing issues of nuclear non-proliferation there is little concrete evidence that it can or ever would be done. It was the same promise industry proponents made about Generation III reactors and failed to deliver.
Australia’s standing on nuclear non-proliferation is currently being diminished because this Government is actively boycotting the current UN process supported by 132 nations on negotiating a treaty to ban nuclear weapons, not because our country has not been funding research into nuclear power.
The Australian Greens fundamentally dissent from this Committee’s findings and believe that no compelling or credible case has been made to proceed with the treaty action. Rushed, limited and opaque decision making processes are a poor basis for public funding allocations in a contested policy arena.