nuclear-news

The Moltex Reactor and used CANDU Fuel

From a MOLTEX Technical Report, issued May 2022:

THE FUEL

The reactor core comprises an array of fuel tubes in a graphite matrix, which fills most of the tank. Each tube sits in a separate channel, within which a molten salt primary coolant circulates.

FUEL SALT

The SSR-U is a fluoride or chloride salt reactor with separate fuel and coolant salts. The fuel is in the form of molten low-enriched uranium fluoride or chloride salt (6% enrichment).

What I find most interesting about this information on the Moltex SMR is that the fuel is enriched uranium, even though we have been led to believe that the Moltex reactor can run on used CANDU fuel, which is certainly not enriched, but depleted in U-235.

For example, consider this announcement by Moltex dated October 3, 2024:

“The SSR-W was specifically engineered to efficiently reuse and consume recycled nuclear waste,” said Moltex CEO Rory O’Sullivan. “This breakthrough research, the result of years of collaboration, clearly demonstrates that ability.” According to this research, the SSR-W can recycle used fuel indefinitely, producing a minimum of 6,000 MW of clean energy from Canada’s existing CANDU reactor fuel without the need for new fuel imports.

Unfortunately, Molex is not very forthcoming about how much fuel their reactor will use. I am going to conservatively assume that 20 tonnes of enriched uranium will be needed for the first year of reactor operation. Based on information I have found in a number of reports on the cost of enriching uranium to 6% U-235, I estimate this will cost about $1 million per tonne. By comparison, the production cost of CANDU fuel is about $250,000 per tonne.

But there are other hidden costs to the production of enriched uranium, one of the most significant being the cost of disposing of the depleted uranium generated by the U-235 enrichment process. Thus, the production of 1 kg of U-235 enriched to 6% generates 12 kg of depleted uranium tailings waste. The uranium enrichment process begins with the conversion of uranium oxide to uranium hexafluoride, UF₆, which is gaseous above 64 ⁰C. UF₆ is very toxic and chemically reactive so it is necessary to convert the depleted UF₆ back to a solid uranium form for safe disposal – adding substantially to the cost of producing enriched fuel for the Moltex reactor.

But there’s still more bad news for the Moltex SMR! Thus, I quote from an article in the May 2023 issue of the Bulletin of the Atomic Scientists by J. Kang et al. entitled: “Canadian reactors that “recycle” plutonium would create more problems than they solve”, where we read:

Moltex’s fresh fuel will consist of potassium chloride, uranium chloride, and plutonium chloride, with some unspecified actinides and lanthanides. Using the expected distribution of plutonium and uranium, and using the ratio of the atomic masses of chlorine and plutonium, one can conclude that the reactor would need about 392 kg of plutonium as fuel every year. In a 2021 presentation, Moltex also mentioned that the average fuel assembly resides for 6.3 years in the reactor. This means that the initial loading for the reactor to start operating would require roughly 2.4 tons of plutonium.

To obtain the 2.4 tons of plutonium required in the startup fuel for a single 300 megawatt-electric (MWe) Moltex reactor, around 577 tons of CANDU spent fuel would have to be processed. In addition, a further 94 tons of CANDU spent fuel must go through Moltex’s waste-to-stable-salts chemical process to produce the necessary fuel for each year of operations. 

December 9, 2024 Posted by Christina Macpherson | technology | Leave a comment

Green Group Sounds Alarm Over Meta’s Nuclear Power Plans

“In the blind sprint to win on AI, Meta and the other tech giants have lost their way,” said a leader at Environment America.

Jessica Corbett, 5 Dec 24, https://www.commondreams.org/news/meta-nuclear-power?xrs=RebelMouse_fb&ts=1733449433&fbclid=IwY2xjawHAsKZleHRuA2FlbQIxMQABHdKFUyPBOBTG7NW2ZlQDOh0gqS_OC0L73I44ICQNjlWw12xPlcO9omTXJQ_aem_Od_q57mbvDma_to2jfZafA

Environmental advocates this week responded with concern to Meta looking for nuclear power developers to help the tech giant add 1-4 gigawatts of generation capacity in the United States starting in the early 2030s.

Meta—the parent company of Instagram, Facebook, WhatsApp, and more—released a request for proposals to identify developers, citing its artificial intelligence (AI) innovation and sustainability objectives. It is “seeking developers with strong community engagement, development, …permitting, and execution expertise that have development opportunities for new nuclear energy resources—either small modular reactors (SMR) or larger nuclear reactors.”

The company isn’t alone. As TechCrunchreported: “Microsoft is hoping to restart a reactor at Three Mile Island by 2028. Google is betting that SMR technology can help it deliver on its AI and sustainability goals, signing a deal with startup Kairos Power for 500 megawatts of electricity. Amazon has thrown its weight behind SMR startup X-Energy, investing in the company and inking two development agreements for around 300 megawatts of generating capacity.”

In response to Meta’s announcement, Johanna Neumann, Environment America Research & Policy Center’s senior director of the Campaign for 100% Renewable Energy, said: “The long history of overhyped nuclear promises reveals that nuclear energy is expensive and slow to build all while still being inherently dangerous. America already has 90,000 metric tons of nuclear waste that we don’t have a storage solution for.”

Do we really want to create more radioactive waste to power the often dubious and questionable uses of AI?” Neumann asked. “In the blind sprint to win on AI, Meta and the other tech giants have lost their way. Big Tech should recommit to solutions that not only work but pose less risk to our environment and health.”

“Data centers should be as energy and water efficient as possible and powered solely with new renewable energy,” she added. “Without those guardrails, the tech industry’s insatiable thirst for energy risks derailing America’s efforts to get off polluting forms of power, including nuclear.”

In a May study, the Electric Power Research Institute found that “data centers could consume up to 9% of U.S. electricity generation by 2030—more than double the amount currently used.” The group noted that “AI queries require approximately 10 times the electricity of traditional internet searches and the generation of original music, photos, and videos requires much more.”

Meta is aiming to get the process started quickly: The intake form is due by January 3 and initial proposals are due February 7. It comes after a rare bee species thwarted Meta’s plans to build a data center powered by an existing nuclear plant.

Following the nuclear announcement, Meta and renewable energy firm Invenergy on Thursday announced a deal for 760 megawatts of solar power capacity. Operations for that four-state project are expected to begin no later than 2027.

December 8, 2024 Posted by Christina Macpherson | technology | Leave a comment

Nuclear fusion: neither imminent nor relevant to climate change

Billions of dollars have been raised on promises of limitless power from nuclear fusion. However, the technology will not deliver affordable power within our lifetimes.

By Ross McCracken, 22/11/2024, 
https://www.energyvoice.com/renewables-energy-transition/563251/nuclear-fusion-neither-imminent-nor-relevant-to-climate-change/

As a child, my father, a senior experimental plasma physicist at the UK’s Culham Laboratory, would tell me that an electricity-generating fusion reactor was just 30 years away. His opinion had not changed by the time he retired, and I believe it would be the same now, if he were alive. But then, he always was an optimist.

With the exception of those on which their business is based, such as France’s EdF, electric utilities in the western world have largely given up on building new nuclear fission reactors. They are expensive; the capital outlay and commercial risks are too high, and they take too long to build.

Market forces and climate policies are now driving the construction of wind and solar farms, which generate cleaner electricity more cheaply, even when energy storage is included. As nuclear power has largely failed as a commercial market proposition, nearly all nuclear newbuild in the world today is heavily state sponsored in one form or another, rather than market driven.

But the nuclear industry is far from out. It has ‘new’ propositions, one of which is still nuclear fusion.

Dubious claims

Private companies have entered the sector, claiming that they can solve the problems encountered by decades of international research with new reactor designs and fusion processes.

Investors hope that innovation from an agile private sector will rejuvenate and overtake the slow process of publicly funded science, represented by the ITER project currently under construction at Cadarache, in France. Fusion will generate limitless clean energy and, in the process, become a key tool for addressing climate change – according to its proponents.

US company Helion, which in 2015 promised a “a useful reactor in the next three years”, now promises a fusion plant by 2028, for example. Microsoft has even agreed to purchase electricity from the facility.

However, the claims of clean, unlimited energy do not stand up to scrutiny. Or as nuclear fusion scientist SJ Zweben put it more bluntly in an article for Physics and Society in January, they are:

“At best wildly optimistic but more often mistaken, delusional, deceitful or fraudulent.”

The scientific and engineering challenges facing nuclear fusion reactors are legion, and as Zweben points out they all need to be resolved at the same time. This is extremely challenging because the solutions proposed for one problem often exacerbate others or create new ones.

The many challenges include energy confinement, impurity contamination, plasma disruptions, wall erosion, the tritium fuel cycle, availability in terms of operational uptime, excessive power consumption by the plant itself, cost and – yes, contrary to industry marketing – radioactive waste.

Spherical Tokamak for Energy Production (STEP)

The UK is basing its fusion hopes on STEP, having left the international ITER project with Brexit. A site has been chosen for the project, but it is not yet clear whether the experiment will garner the same support from the current government as it did from the previous one.

In a recent article for Physics World, fusion scientist Guy Matthews noted that the energy stored in STEP’s plasma would need to be about 5,000 times larger than that produced in the UK’s MAST-U spherical tokamak experiment. He describes the single giant leap to a power plant as “an extreme, and unprecedented, extrapolation of physics and technology”.

It may even be dangerous. There is no way yet of reliably avoiding or mitigating plasma instabilities, known as ‘disruptions’. Without a robust solution, the consequent damage “would render a power plant inoperable”.

Other experienced fusion scientists share these and other concerns.

John Evans, who worked at the Atomic Energy Research Establishment in Harwell, recently highlighted the lack of a proven solution for the fusion fuel cycle.

This involves breeding and reprocessing unprecedented quantities of radioactive tritium – a hydrogen isotope that does not occur naturally and needs to be generated from a massive ‘breeding blanket’ containing lithium. A solution must be in place before any fusion power plant can operate and each fusion plant would consume, annually, more tritium than is currently available globally.

Put simply, the technical and scientific challenges posed by any approach to fusion, whether using spherical, ‘toroidal’ tokamaks or lasers, are huge.

Will fusion be clean?

According to the International Atomic Energy Agency (IAEA), “Fusion does not create any long-lived radioactive waste”. This is true only in theory.

A fusion reactor produces helium, an inert gas, as a result of a fusion reaction between the hydrogen isotopes tritium and deuterium. Tritium is very radioactive with a half-life of 12.3 years. The tritium is both produced and consumed by the fusion reactor so, in a perfect world, there is no nuclear waste.However, 80% of the power from the fusion reaction is delivered as fast neutrons that generate the tritium from the surrounding breeding blanket, which is likely to require periodic replacement.Nuclear reactions between the neutrons, and impurities or primary elements in the blanket, make it radioactive and degrade the materials – i.e. increasing the need for replacement.Materials in a more compact fusion reactor, like STEP, would accumulate neutron damage more rapidly and would therefore need more frequent replacement.

As a result, Matthews provides a somewhat different message to the IAEA: “If conventional engineering materials are used, fusion reactors have the potential to generate far larger volumes of long-lived radioactive waste than fission reactors.”

The extent to which suitable low-activation fusion materials can be developed to mitigate this challenge at an acceptable cost is one of the many unsolved problems facing fusion power.

A neutron-free fusion reaction is possible using hydrogen and boron, but for this to work the plasma temperature needs to be around 7,000 million degrees – which makes the deuterium-tritium reaction (JET, ITER), at a mere 100 million degrees, seem like a walk in the park.

Fusion’s costs are misunderstood or ignored

Fusion advocates use the term ‘limitless’ energy to imply cheap energy. But will fusion provide either?

It could be limitless in the sense that the base fuel sources – lithium and deuterium – are abundant and only relatively small amounts are required to produce huge amounts of power. Unfortunately, the idea that a limitless or near-limitless energy source means cheap energy is plain wrong because, however energy is generated, it has a cost.

A nuclear fusion power plant will have a capital cost, an operational cost and a maximum generating capacity like any other power plant. The price of a first-of-a-kind reactor will be huge and an ‘nth of a kind’ reactor will not be cheap. ITER’s costs are currently estimated at €18-22 billion, but will likely prove much higher and it is an experiment – not a power plant.

STEP’s cost is estimated to run to several billion pounds before construction has even started and it is a far more challenging project. Moreover, the role of STEP (if successful) is only to provide a “pathway to commercialisation” according to Howard Wilson, fusion pilot plant lead at the US’ Oak Ridge National Laboratory.

Cost trajectory

For wide-scale deployment, fusion must be economically viable. The general ‘rule’ used in forecasting future costs is that they halve as production of a commodity doubles. However, this is a popularisation and over-optimistic simplification of Wright’s Law, which states that for every cumulative doubling of units produced, costs will fall by a constant percentage.

The extent of that percentage is usually governed by the complexity of the technology concerned and the degree to which it can be modularised and subject to the cost gains of mass manufacturing. Technical complexity and safety concerns, when major, mean that the cost reduction of higher production volumes can be small or non-existent.

Just as nuclear fission has struggled to follow Wright’s Law, there is no reason to believe that fusion, which is much more complex, will be any more successful.

Relevance to climate change

Nuclear fusion is still decades away from working (i.e. producing sustainable net energy gains), and then decades more from economic viability. Even then, it would be more decades still from deployment on a scale large enough to have any impact on climate change.

It is almost 2025, and to remain on track to limit global warming to 1.5°C above pre-industrial levels, the world, not just individual countries, needs to achieve net-zero carbon by 2050. It is a goal that is already slipping away. Fusion is simply too far off to be of any use.

Ross McCracken is a freelance energy analyst with more than 25 years experience, ranging from oil price assessment with S&P Global to coverage of the LNG market and the emergence of disruptive energy transition technologies.

November 26, 2024 Posted by Christina Macpherson | technology | Leave a comment