It will not be easy, then, for minister Pichetto Fratin and for the Meloni government to change the legislative framework on nuclear power. Minister Pichetto has promised: “Yes, I will give it my all. This is the mandate of the government and of Parliament. I am working with a working group that must deal with the legal framework. If you want to buy a small modular reactor (small modular fission reactors, editor’s note), there must be a compatible legal framework”.
So here is the word, or the magic formula. SMR. Small Modular Reactor.
Setting aside the ease with which the minister’s words seem to suggest one can obtain one of these new-generation mini-reactors, , here we touch the core (and not only the nuclear one) of the matter.
What are SMRs? What is their real technological novelty compared with the colossal traditional power stations we are used to seeing? And above all, are they truly safe, with zero impact on the environment?
In short: is there a ‘green’ nuclear power for our future, or are the scenarios not as rosy as many are painting them?
Greentomeet has decided to offer its readers the independent opinion of an expert in nuclear matters.
He is the American Edwin Lyman, one of the world’s most recognised experts on nuclear proliferation and nuclear terrorism, as well as on nuclear power safety and security. A member of the Institute of Nuclear Materials Management, Lyman has testified many times before Congress and the Nuclear Regulatory Commission.
On the website of the Union of concerned scientists, an article by him appeared on 30 April on the question of the safety of latest-generation nuclear power, which neatly sums up the debate in five clear points.
The title is in fact:
Five things the ‘nuclear bros’ (the “brothers of nuclear power”, that is, essentially the whole lobby pushing for new power stations) don’t want you to know about small modular reactors.
You can read the full article in English at this link:
https://blog.ucsusa.org/edwin-lyman/five-things-the-nuclear-bros-dont-want-you-to-know-about-small-modular-reactors/?fbclid=IwZXh0bgNhZW0CMTAAAR1s3AoPZRVp48Gyvw6ZRw1_pRvHFjgHELn5b6g8PVs9M_EKohzqO6Vygr8_aem_AXPo_zdKg07_myIdcm5UppCiXV8ayXUesoPtPtN46eH64Kc59vPYRwUs33GMM_w7TmB3va6s3-X1alVmz8BCamsF
Let us see what Lyman says.
“Even those who follow energy and climate issues only casually have probably heard of the alleged wonders of small modular nuclear reactors (SMRs)”, the author begins.
“This is largely due to the ‘nuclear bros’: an active and seemingly tireless group of nuclear power advocates who dominate social media discussions on energy by promoting SMRs and other ‘advanced’ nuclear technologies as the only real solution to the climate crisis”.
“But as I showed in my 2013 and 2021 reports, the hype surrounding SMRs is decidedly overblown, and my conclusions still hold today”.
What are SMRs?
Lyman explains clearly what we are talking about.
“SMRs are ‘small’ nuclear reactors (defined as 300 megawatts of electrical power or less), which can be largely assembled in a centralised facility and would be installed modularly at power generation sites. Some proposed SMRs are so small (20 megawatts or less) that they are called ‘micro’ reactors. SMRs differ from today’s conventional nuclear power stations, which are typically around 1,000 megawatts and have been largely custom built. Some SMR designs, such as NuScale, are modified versions of operating water-cooled reactors, while others are radically different designs that use coolants other than water, such as liquid sodium, helium gas or even molten salts”.
So far, however, theoretical interest in SMRs has not produced many orders for real reactors.
“The only SMR currently under construction is the Chinese one. In the United States, only one company – TerraPower, founded by Microsoft’s Bill Gates – has applied to the Nuclear Regulatory Commission (NRC) for permission to build a power reactor (but at 345 megawatts, it is technically not even an SMR)”.
And so we know that China is at the forefront of this new frontier of nuclear reactors, and Microsoft has also stepped in, among the first companies to be interested.
“Developers in the sector and the US Department of Energy argue that SMRs can be cheaper and quicker to build than large reactors”, Lyman continues, “and that their modular nature makes it easier to balance energy supply and demand. They also argue that reactors of various sizes would be useful for a range of applications beyond grid electricity, including supplying process heat to industrial plants and power to data centres, cryptocurrency mining operations, petrochemical production and even electric vehicle charging stations”.
But let us get to the five ‘hot’ points. That is, the critical issues that, according to Lyman, “the nuclear industry and the nuclear advocates who promote its message don’t want you, the public, to know”.
1. SMRs are not cheaper than large reactors.
“In theory”, the author argues, “small reactors should have lower capital costs and construction times than large reactors of a similar design.
But this does not mean that small reactors are cheaper than large ones. In fact, the opposite is usually true. What matters most when comparing the economics of different energy sources is the cost of producing a kilowatt-hour of electricity, which depends on the capital cost per kilowatt of generating capacity, as well as on operating, maintenance and fuel costs and other factors”.
If we look at economies of scale, Lyman explains, “smaller reactors will generally produce more expensive electricity than larger ones. For example, NuScale’s now-cancelled project to build a 460-megawatt, 6-unit SMR in Idaho was estimated to cost more than $20,000 per kilowatt, higher than the actual cost of the large Vogtle reactor project, which was over $15,000 per kilowatt”.
“This cost penalty can only be offset by radical changes in the way reactors are designed, built and operated”.
But even the changes proposed by engineers do not so far seem to bring down the cost per kilowatt-hour significantly.
For example, Lyman argues, “one way in which SMR developers are trying to cut capital cost is by reducing or eliminating many of the safety features required for operating reactors that provide multiple layers of protection, such as a robust reinforced-concrete containment structure, motor-driven emergency pumps, and strict quality assurance standards for backup safety equipment such as power supplies. But these changes have so far not had a big impact on overall costs, as NuScale shows”.
“In addition to capital cost, operating and maintenance (O&M) costs will also have to be reduced significantly to improve the competitiveness of SMRs. However, some operating expenses, such as the security needed to protect against terrorist attacks, would not normally be sensitive to reactor size. The relative contribution of O&M and fuel costs to the price per megawatt-hour varies greatly depending on design and project details, but could be 50% or more, depending on factors such as the interest rates that affect the total cost of capital”.
Lyman’s conclusion on this point is clear.
“Overall, these changes might be enough to make some SMRs cost-competitive with large reactors, but the road to competing with renewable technologies is still long. The levelised cost of electricity for the now-cancelled NuScale project was estimated at around $119 per megawatt-hour (without federal subsidies), while onshore wind and utility-scale solar today cost less than $40/MWh.
2. SMRs are generally not safer than large light-water reactors.
While their small size might lead us to think that small nuclear reactors pose lower risks to public health and the environment than large reactors, Lyman has more than one doubt on the matter.
“The so-called passive safety features that SMR advocates like to cite”, that is, the idea that objectively everything is smaller and therefore safer and more controllable, “may not always work, especially in extreme events such as major earthquakes, large floods or fires that can degrade the environmental conditions in which they are designed to operate”.
On the contrary, in some cases passive features can even make accidents worse. “For example, the NRC’s review of the NuScale design revealed that passive emergency systems could deplete the cooling water of boron, which is needed to keep the reactor safely shut down after an accident”.
Just to be on the safe side, though, regulators in the US are relaxing safety requirements for SMRs in such a way as to cancel out any safety benefit deriving from passive features.
“For example, in recent years the NRC has approved rules and procedures that provide regulatory pathways to exempt new reactors, including SMRs, from many of the protective measures required for operating plants, such as a physical containment structure, an off-site emergency evacuation plan and an exclusion zone separating the plant from densely populated areas. The Commission is also considering further changes that could allow SMRs to reduce the number of armed security personnel protecting them from terrorist attacks and of highly qualified operators needed to run them.”
Conclusion: “Reduced security at SMRs is particularly worrying, because even the safest reactors could effectively become dangerous radiological weapons if they were sabotaged by skilled attackers. Even passive safety mechanisms could be deliberately disabled.”
SMRs could be just as dangerous as large reactors, or even more so.
“For example, if a containment structure in a large reactor reliably prevents the release of 90% of the radioactive material from the reactor core during a meltdown, then a reactor 5 times smaller without such a containment structure could plausibly release more radioactive material into the environment, even though the total amount of material in the core would be smaller. Moreover, if the SMR were located close to populated areas without off-site emergency plans, more people could be exposed to dangerously high levels of radiation.”
That is already enough to make us think hard about the issue. For now, let us stop here.
In the next article we will look at the other three points, no less interesting, identified by Lyman. Starting with the crucial question: what about the waste?
