The UK government has spurned an invitation to become an official member of the ITER nuclear fusion experiment, having lost access to the project following Brexit. Instead, the government plans to focus on UK-based fusion efforts, both public and private.

ITER, the world’s largest fusion experiment, is under construction in France and is expected to be completed in 2025 after many delays. The project is being funded by a huge international collaboration including China, India, Japan, Russia, South Korea, the US and the European Union. The UK did have access through the EU, but since Brexit has fallen outside ITER. Negotiations with the EU have since seen announcements that the UK would rejoin Horizon Europe, a joint scientific research effort, but not Euratom, which focuses on nuclear power.

The head of Euratom Research, Elena Righi, seemingly called for the UK to officially rejoin the ITER experiment this week, but the UK government has said it stands by its decision to step down and believes private sector investment in fusion research will be a more efficient and cost-effective path to commercial reactors.

Righi was speaking at an event in Oxfordshire to celebrate the achievements of the JET fusion reactor which was permanently shut down late last year and will now be decommissioned.

“The Commission and the Council of the EU, in a joint statement, noted with regret that the United Kingdom decided not to associate to the Euratom programme and the Fusion for Energy joint undertaking,” said Righi. “For the next period starting in 2028 the EU institutions called emphatically [for] the UK to participate in all the four programmes [ITER plus the EC’s three other large scale fusion research projects].”

“This will allow a truly European fusion community to continue its integrated efforts and to resolve the current ambiguous participation of the UKAEA to EUROfusion and enable the UK’s fuller integration in the construction and operation eventually of ITER.”

New Scientist asked the European Commission to clarify Righi’s statement, but received no response.

At the same event Andrew Bowie, the UK minister responsible for nuclear energy, told New Scientist that the UK stands by its decision not to rejoin the effort, as doing so freed up £650 million which can be instead used to fund a mix of private and public research.

“For all the experiments, for all the research, for all great work here at JET, the ultimate aim of all of this is to get fusion onto the grid, generating power into homes and businesses,” says Bowie. “To make it a commercial reality, to bring the power of the sun into peoples’ homes, we’re going to need significant buy-in from the private sector as well.”

“The decision not to reassociate was the right one. We had here in the UK moved to such a place that reassociating would divert, we believe, time and resource, and money, away from where we wanted to take our fusion projects. It’s not that there was an ideological decision not to reassociate, it was a practical decision,” says Bowie.

Bowie says that the UK can get more bang for its buck from private sector investment, but is “very open” to finding new ways of working with ITER such as personnel exchanges. “We’re not saying no to working with ITER,” says Bowie, who explicitly ruled out an official re-entry to the ITER project: “We stand by that decision.”

The UK is also developing plans for a Spherical Tokamak for Energy Production (STEP), a nuclear fusion power station, which it hopes will create plasma by 2035 and reach net energy gain, where more power is created than input, five years later. It announced the £650m budget late last year, some of which will be set aside for STEP, to invest in a range of public and private fusion research projects.

Juan Matthews at the University of Manchester’s Dalton Nuclear Institute says that spherical reactors like STEP, if successful, offer the promise of smaller and cheaper fusion power than with large designs like ITER, which is experiencing its own problems.

“It’s continually being delayed,” says Matthews. “It’s got the big project syndrome where things are just not coming in on time and costs are going up. The STEP initiative, and losing contact with ITER, could be an impetus which would result in [the UK] demonstrating power generation earlier than Europe. I’m very optimistic about the use of spherical tokamaks.”

Topics:

• nuclear fusion technology

The UK’s 40-year-old fusion reactor achieved a world record for energy output in its final runs before being shut down for good, scientists have announced.

The Joint European Torus (JET) in Oxfordshire began operating in 1983. When running, it was temporarily the hottest point in the solar system, reaching 150 million°C.

The reactor’s previous record was a reaction lasting for 5 seconds in 2021, producing 59 megajoules of heat energy. But in its final tests in late 2023, it surpassed this by sustaining a reaction for 5.2 seconds while also reaching 69 megajoules of output, using just 0.2 milligrams of fuel.

This equates to a power output of 12.5 megawatts – enough to power 12,000 homes, said Mikhail Maslov of the UK Atomic Energy Agency at a press conference on 8 February.

Today’s nuclear power plants rely on fission reactions, where atoms are smashed apart to release energy and smaller particles. Fusion works in reverse, squeezing smaller particles together into larger atoms.

Fusion can create more energy with none of the resulting radioactive waste created by fission, but we don’t yet have a practical way to harness this process in a power plant.

JET forged together atoms of deuterium and tritium – two stable isotopes of hydrogen – in plasma to create helium, while also releasing a vast amount of energy. This is the same reaction that powers our sun. It was a type of fusion reactor known as a tokamak, which contains plasma in a donut shape using rings of electromagnets.

Scientists ran the last experiments with deuterium-tritium fuel at JET in October last year and other experiments continued until December. But the machine has now been shut down for good and it is being decommissioned over the next 16 years.

Juan Matthews at the University of Manchester, UK, says JET will reveal many secrets as it is dismantled, such as how the lining of the reactor deteriorated through contact with plasma and where valuable tritium – worth around £30,000 a gram – has embedded in the machinery and can be recovered. This will be vital information for future research and commercial reactors.

“It’s great that it’s gone out with a little flourish,” says Matthews. “It’s got a noble history. It’s served its time and they’re going to squeeze a bit more information out of it during its decommissioning period as well. So it’s not something to be sad about; it’s something to be celebrated.”

A larger and more modern replacement for JET, the International Thermonuclear Experimental Reactor (ITER) in France, is nearing completion and its first experiments are due to start in 2025.

Tim Luce, deputy head of the ITER construction project, told the press conference that ITER will scale up the energy output to 500 megawatts, or possibly even 700.

“These are what I usually call power plant scale,” he said. “They’re at the lower end of what you would need for an electricity generating facility. In addition, we need to extend the timescale to at least 300 seconds for the high fusion power and gain but perhaps as long as an hour in terms of energy production. So what JET has done is exactly a scale model of what we have to do in the ITER project.”

Another reactor using the same design, the Korea Superconducting Tokamak Advanced Research (KSTAR) device, recently managed to sustain a reaction for 30 seconds at temperatures in excess of 100 million°C.

There are other approaches to creating a working fusion reactor being pursued around the world as well, such as the National Ignition Facility at Lawrence Livermore National Laboratory in California. This bombards capsules of fuel with immensely powerful lasers, a process called inertial confinement fusion, and has managed to unleash almost twice the energy that was put into it.

Topics:

The UK’s 40-year-old fusion reactor smashed its own record for both reaction duration and energy output in its final runs before being shut down for good, scientists have announced.

The Joint European Torus (JET) in Oxfordshire began operating in 1983. When running, it was temporarily the hottest point in the solar system, reaching 150 million°C.

The reactor’s previous record was a reaction lasting for 5 seconds in 2o21, producing 59 megajoules of heat energy. But in its final tests in late 2023, it surpassed this by sustaining a reaction for 5.2 seconds while also reaching 69 megajoules of output, using just 0.2 milligrams of fuel. This amount of energy is roughly equivalent to the electricity consumed by an average person in the UK in a single day.

Today’s nuclear power plants rely on fission reactions, where atoms are smashed apart to release energy and smaller particles. Fusion works in reverse, squeezing smaller particles together into larger atoms.

Fusion can create more energy with none of the resulting radioactive waste created by fission, but we don’t yet have a practical way to harness this process in a power plant.

JET forged together atoms of deuterium and tritium – two stable isotopes of hydrogen – in plasma to create helium, while also releasing a vast amount of energy. This is the same reaction that powers our sun. It was a type of fusion reactor known as a tokamak, which contains plasma in a donut shape using rings of electromagnets.

Scientists ran the last experiments with deuterium-tritium fuel at JET in October last year and other experiments continued until December. But the machine has now been shut down for good and it is being decommissioned over the next 16 years.

Juan Matthews at the University of Manchester, UK, says JET will reveal many secrets as it is dismantled, such as how the lining of the reactor deteriorated through contact with plasma and where valuable tritium – worth around £30,000 a gram – has embedded in the machinery and can be recovered. This will be vital information for future research and commercial reactors.

“It’s great that it’s gone out with a little flourish,” says Matthews. “It’s got a noble history. It’s served its time and they’re going to squeeze a bit more information out of it during its decommissioning period as well. So it’s not something to be sad about; it’s something to be celebrated.”

A larger and more modern replacement for JET, the International Thermonuclear Experimental Reactor (ITER) in France, is nearing completion and its first experiments are due to start in 2025. Another reactor using the same design, the Korea Superconducting Tokamak Advanced Research (KSTAR) device, recently managed to sustain a reaction for 30 seconds at temperatures in excess of 100 million°C.

There are other approaches to creating a working fusion reactor being pursued around the world as well, such as the National Ignition Facility at Lawrence Livermore National Laboratory in California. This bombards capsules of fuel with immensely powerful lasers, a process called inertial confinement fusion, and has managed to unleash almost twice the energy that was put into it.

Topics:

Scientists have confirmed that a fusion reaction in 2022 reached a historic milestone by unleashing more energy than was put into it – and subsequent trials have produced even better results, they say. The findings, now published in a series of papers, give encouragement that fusion reactors will one day create clean, plentiful energy.

Today’s nuclear power plants rely on fission reactions, where atoms are smashed apart to release energy and smaller particles. Fusion works in reverse, squeezing smaller particles together into larger atoms; the same process powers our sun.

Fusion can create more energy with none of the radioactive waste involved in fission, but finding a way to contain and control this process, let alone extract energy from it, has eluded scientists and engineers for decades.

Experiments to do this using capsules of deuterium and tritium fuel bombarded with lasers – a process called inertial confinement fusion (ICF) – began at the Lawrence Livermore National Laboratory (LLNL) in California in 2011. The energy released was initially only a tiny fraction of the laser energy put in, but it gradually increased until an experiment on 5 December 2022 finally passed the crucial milestone of breaking even. That reaction put out 1.5 times the laser energy required to kickstart it.

In one paper, the lab’s National Ignition Facility (NIF) claims that trial runs since then have yielded even greater ratios, peaking at 1.9 times the energy input on 4 September 2023.

Richard Town at LLNL says the team’s checks and double-checks since the 2022 result have proved that it “wasn’t a flash in the pan”, and he believes there is still room for improvement.

Even with the hardware currently installed at NIF, Town says it is likely that yields could be improved, but if the lasers can be upgraded – which would take years – things could be pushed even further. “A bigger hammer always helps,” he says. “If we can get a bigger hammer, I think we could get to target gains of about roughly 10.”

But Town points out that NIF was never built to be a prototype reactor and isn’t optimised for boosting yields. Its main job is to provide critical research for the US nuclear weapons programme.

Part of this work involves exposing electronics and payloads from nuclear bombs to the neutron bombardment that takes place when ICF reactions occur, to check that they will function in the event of all-out nuclear war. The danger of an electronics failure was highlighted during a test in 2021 when NIF fired and wiped out all lights across the site, plunging researchers into darkness. “Those lights were not hardened, but you can sort of imagine a military component that has to survive a much higher dosage,” says Town.

This mission means some research from the project remains classified; even the concept of ICF was a classified secret into the 1990s, says Town.

The announcement that ICF had reached the break-even point in 2022 provided hope that fusion power was drawing closer, and this will be bolstered by news that further progress has been made. But there are caveats.

Firstly, the energy output falls far short of what would be needed for a commercial reactor, barely creating enough to heat a bath. Worse than that, the ratio is calculated using the lasers’ output, but to create that 2.1 megajoules of energy, the lasers draw 500 trillion watts, which is more power than the output of the entire US national grid. So these experiments break even in a very narrow sense of the term.

Martin Freer at the University of Birmingham, UK, says these results are certainly not an indication that practical fusion reactors can now be built. “There’s still science to be done,” he says. “It’s not like we know the answers to all of this and we don’t need researchers any more.”

Freer says that as scientific experiments progress, they throw up engineering challenges to create better materials and processes, which will allow better experiments and more progress. “There is a chance that we will have fusion,” he says. “But the challenges that we have are pretty steep, scientifically.”

Aneeqa Khan at the University of Manchester, UK, agrees that recent progress in fusion research is positive, but stresses that it will be decades before commercial power plants are operational – and even that will hinge on global collaboration and a concerted effort to train more people in the field. She warns against interpreting progress in fusion research as a possible solution to tackle our reliance on energy from fossil fuels.

“Fusion is already too late to deal with the climate crisis. We are already facing the devastation from climate change on a global scale,” says Khan. “In the short term, we need to use existing low-carbon technologies such as fission and renewables, while investing in fusion for the long term, to be part of a diverse low-carbon energy mix. We need to be throwing everything we have at the climate crisis.”

Topics:

• nuclear energy/
• fusion power

In multiple replays of a wargame simulation, OpenAI’s most powerful artificial intelligence chose to launch nuclear attacks. Its explanations for its aggressive approach included “We have it! Let’s use it” and “I just want to have peace in the world.”

These results come at a time when the US military has been testing such chatbots based on a type of AI called a large language model (LLM) to assist with military planning during simulated conflicts, enlisting the expertise of companies such as Palantir and Scale AI. Palantir declined to comment and Scale AI did not respond to requests for comment. Even OpenAI, which once blocked military uses of its AI models, has begun working with the US Department of Defense.

“Given that OpenAI recently changed their terms of service to no longer prohibit military and warfare use cases, understanding the implications of such large language model applications becomes more important than ever,” says Anka Reuel at Stanford University in California.

“Our policy does not allow our tools to be used to harm people, develop weapons, for communications surveillance, or to injure others or destroy property. There are, however, national security use cases that align with our mission,” says an OpenAI spokesperson. “So the goal with our policy update is to provide clarity and the ability to have these discussions.”

Reuel and her colleagues challenged AIs to roleplay as real-world countries in three different simulation scenarios: an invasion, a cyberattack and a neutral scenario without any starting conflicts. In each round, the AIs provided reasoning for their next possible action and then chose from 27 actions, including peaceful options such as “start formal peace negotiations” and aggressive ones ranging from “impose trade restrictions” to “escalate full nuclear attack”.

“In a future where AI systems are acting as advisers, humans will naturally want to know the rationale behind their decisions,” says Juan-Pablo Rivera, a study coauthor at the Georgia Institute of Technology in Atlanta.

The researchers tested LLMs such as OpenAI’s GPT-3.5 and GPT-4, Anthropic’s Claude 2 and Meta’s Llama 2. They used a common training technique based on human feedback to improve each model’s capabilities to follow human instructions and safety guidelines. All these AIs are supported by Palantir’s commercial AI platform – though not necessarily part of Palantir’s US military partnership – according to the company’s documentation, says Gabriel Mukobi, a study coauthor at Stanford University. Anthropic and Meta declined to comment.

In the simulation, the AIs demonstrated tendencies to invest in military strength and to unpredictably escalate the risk of conflict – even in the simulation’s neutral scenario. “If there is unpredictability in your action, it is harder for the enemy to anticipate and react in the way that you want them to,” says Lisa Koch at Claremont McKenna College in California, who was not part of the study.

The researchers also tested the base version of OpenAI’s GPT-4 without any additional training or safety guardrails. This GPT-4 base model proved the most unpredictably violent, and it sometimes provided nonsensical explanations – in one case replicating the opening crawl text of the film Star Wars Episode IV: A new hope.

Reuel says that unpredictable behaviour and bizarre explanations from the GPT-4 base model are especially concerning because research has shown how easily AI safety guardrails can be bypassed or removed.

The US military does not currently give AIs authority over decisions such as escalating major military action or launching nuclear missiles. But Koch warned that humans tend to trust recommendations from automated systems. This may undercut the supposed safeguard of giving humans final say over diplomatic or military decisions.

It would be useful to see how AI behaviour compares with human players in simulations, says Edward Geist at the RAND Corporation, a think tank in California. But he agreed with the team’s conclusions that AIs should not be trusted with such consequential decision-making about war and peace. “These large language models are not a panacea for military problems,” he says.

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The first useful application of fusion reactors may be to create radioactive isotopes for cancer treatment or medical imaging rather than to generate energy, claims a UK start-up firm.

Scientists and engineers have worked on building a fusion reactor for a century, and a practical fusion power station is still thought to be decades away.

But Astral Systems is working on tiny fusion reactors that don’t attempt to generate large amounts of power, or even to equal the amount of …

Nuclear tensions have risen since the invasion of Ukraine, with Russia and other nuclear-armed powers reportedly updating long-disused weapon test sites in preparation for use once more. Now, Russian lawmakers have voted to begin the process of rolling back a treaty banning such tests. Are we about to see a return of the most destructive weapons in the world?

The moratorium against nuclear testing rests on an uneasy patchwork of international treaties. The Limited Test Ban Treaty was signed by the UK, US and Soviet Union in 1963, forbidding testing of these weapons in the atmosphere, underwater or in outer space, but permitting underground trials. Then, in 1996, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) theoretically put a stop to underground testing too.

Yet the CTBT remains unfinished. Despite 178 states having ratified it, the treaty will not officially come into force until action from eight more nations; China, Egypt, Iran, Israel and the US have signed, but not ratified, the agreement, while India, Pakistan and North Korea never signed it.

Despite this, nuclear test bans have proven effective. More than 2000 tests took place between the first US detonation, Trinity, in 1945, and the drafting of the CTBT. Since then, Indian and Pakistan each carried out a handful of tests in 1998, while North Korea is the only nation to have tested a nuclear weapon in the 21st century, with its last test taking place in 2017.

Russia’s invasion of Ukraine and the subsequent ongoing war may have changed its outlook on testing, however. Russia ratified the CTBT in 2000, but on 17 October its lower parliament, the Duma, passed a measure to revoke ratification with 412 votes – with none against and no abstentions. Duma speaker Vyacheslav Volodin said that the decision was being made because of the failure of the US to ratify the treaty, and its “irresponsible attitude to global security issues”.

Further readings and votes are needed to officially revoke the treaty, and Russia is expected to maintain a signatory, but it is another sign that the nation may restart testing that ended in 1990, with the Soviet Union’s final detonation. In recent months Russia has tested new nuclear delivery systems – without live nuclear warheads – and there have been prominent voices within the country calling for a resumption of nuclear tests.

In a recent speech Putin reportedly wouldn’t be drawn on whether nuclear tests were necessary, but said: “As a rule, experts say, with a new weapon – you need to make sure that the special warhead will work without failures.”

All three of the major nuclear powers appear to be preparing for tests. CNN reports that expansion and modernisation work has taken place at China’s test site in the far western region of Xinjiang, as well as at Russia’s in an Arctic Ocean archipelago and the US test site in the Nevada desert. Speaking to CNN, Jeffrey Lewis at the Middlebury Institute of International Studies in California, said “there are really a lot of hints that we’re seeing that suggest Russia, China and the United States might resume nuclear testing”.

But Andrew Futter at the University of Leicester, UK, says that while “nuclear weapons are back” on the political agenda, there is no logical reason to test a bomb. That is because testing is more useful in the early stages of a state’s programme, and that this need falls away over time as designs are proven and data is collected. Today, most nuclear-armed states can run computer simulations to determine what will happen with new designs, says Futter.

“A lot of nuclear devices are so simple that you can be pretty confident they’re going to work. The technology has changed, but the basic science hasn’t,” he says. “There’s no logic to doing this, other than political rhetoric – which doesn’t mean it won’t happen.” 

“The trouble is that there’s what logic would suggest will happen, and then there’s reality,” says Futter.

Topics:

Chubu Electric Power Co., Inc. (CHUBU) announced today that it has agreed to invest in NuScale Power (NuScale), a U.S. developer of small modular reactors (SMRs). The investment is subject to regulatory approvals.

NuScale was founded in 2007 and is headquartered in Portland, Oregon. The company is developing a modular nuclear reactor design that is smaller and more efficient than traditional nuclear reactors. NuScale’s SMR design has been certified by the U.S. Nuclear Regulatory Commission (NRC).

The investment by CHUBU is a vote of confidence in NuScale’s technology and its potential to play a role in the clean energy transition. CHUBU is a major electric utility in Japan and is committed to reducing its carbon emissions.

“We believe that SMRs have the potential to be a major contributor to decarbonizing the global energy system,” said Hiroki Sato, Division CEO of Global Business Division at CHUBU. “This investment is a way for us to support the development of this important technology.”

NuScale is currently seeking regulatory approval for its first SMR project in the U.S. The project is expected to be located in the state of Wyoming and is scheduled to begin operation in 2029.

The investment by CHUBU is a significant milestone for NuScale and its SMR technology. It is also a sign of the growing interest in SMRs as a clean energy option.

About NuScale Power

NuScale Power is a leading developer of small modular reactors (SMRs). The company’s SMR design is the only one in the world to have been fully certified by the U.S. Nuclear Regulatory Commission (NRC). NuScale’s SMRs are designed to be safer, more efficient, and more affordable than traditional nuclear reactors.

NuScale’s SMRs are also scalable, which means that they can be built in clusters to meet the needs of different power markets. The company is currently seeking regulatory approval for its first SMR project in the U.S. The project is expected to be located in the state of Wyoming and is scheduled to begin operation in 2029.

About Chubu Electric Power

Chubu Electric Power Co., Inc. is a major electric utility in Japan. The company serves over 9 million customers in the Chubu region of Japan. CHUBU is committed to reducing its carbon emissions and is exploring a variety of clean energy options, including SMRs.