Posts Tagged Thorium

Advanced nuclear can support wind and solar

Posted by Stephen Tindale on March 9th, 2017

Last week I went to Amsterdam to speak at a seminar on ‘nuclear: the elephant in the room’. The Netherlands has only one operating nuclear power station, Borssele, providing about 4% of the power generated in the country. The Netherlands is very flat (and much of it below sea level) so hydro is not an option. This explains why the Netherlands currently gets only around 6.5% of its energy from renewables. The Dutch target under the EU Renewable Energy Directive is to get 14% of total energy from renewables by 2020. Major expansions of on- and offshore wind are underway. But where should the other 86% come from?

The Netherlands has substantial gas resources, so a lot of gas power stations. Gas is less bad for the climate than coal is, and an effective way to back up intermittent renewables such as wind. But gas without carbon capture and storage is not low carbon enough to be regarded as clean (as we argued in

The Dutch go to the polls on 15 March. None of the 28 parties standing in the general election is proposing a new nuclear power station. So the reference to the elephant in the room was appropriate.

The role that nuclear could play was well set out by Pier Stapersma of Clingendael, the Netherlands Institute for International Relations ( Pier pointed out that it is possible for nuclear reactors to ‘load follow’ – operate as back up to intermittent wind – and that smaller reactors can do this more efficiently than large reactors can.

Despite the lack of political engagement with nuclear issues, there is some important nuclear research underway in the Netherlands, notably into thorium molten salt reactors at the Delft University of Technology. The website states that “Sun and wind are intermittent energy sources, that require backup. Thorium MSR’s are excellent for providing this. MSR’s can ‘load follow’ automatically, by laws of nature. This means that if demand goes up, they produce more, if it goes down, they produce less.” (

There is also research into thorium MSRs being done in Denmark, by Copenhagen Atomics ( I met staff from Copenhagen Atomics at the seminar. Denmark has traditionally been anti-nuclear: the smiling sun Nuclear Power: no thanks logo was created in Denmark in 1975 (, and the country has no nuclear power stations.

Copenhagen Atomics aim to build a “waste burner”, using the legacy of past nuclear activities. Weinberg Next Nuclear’s next report will be on this subject. Advanced nuclear technology, including Molten Salt Reactors, have potential to engage previously anti-nuclear audiences. Alongside their energy security and cost reduction potential, this makes them worth investing in.

UK Parliamentary Committee backs thorium R&D

Posted by David Martin on December 24th, 2014


Source: Adrian Pingstone/Wikipedia. Both ends of Parliament now call on the government to support nuclear R&D.

Last week the House of Commons’ Energy & Climate Change Committee released the long-awaited final report of its Inquiry into Small Nuclear Power. The report is well-researched, cautious, and strongly recommends that the Government thoroughly assess the feasibility and economics of small nuclear power plants.

Most welcome, the Committee issued clear backing for thorium R&D in the UK, saying that the, “UK must remain an active participant in thorium research and development”. The Committee went even further, calling on the Government to commission an in-depth study “to confirm the benefits of thorium in the longer-term and how any potential barriers to its use might be overcome” (ECCC report, p.9).

We hope that the Government will follow up the Committee’s recommendations with concerted action, and look forward to reading the terms of the thorium study in the New Year. As an essential precursor, the Government must recognise the economic benefits of nuclear R&D and recommit to programmes of nuclear research.

Thorium fuels and thorium-fuelled reactors deserve thorough economic assessment but, whilst that review is ongoing, the Government must make sure that UK institutions maintain their early lead in thorium R&D. With a little help, UK organisations could become world leaders in developing this most promising clean energy technology. Three recent examples of the UK’s world-leading thorium R&D:

  • –The UK National Nuclear Laboratory designed prototype thorium fuels for Thor Energy. This fuel is currently being tested in the Halden reactor in Norway;
  • –The University of Manchester co-designed the U-Battery micro-reactor, a compact high-temperature reactor which is part-fuelled by thorium

In the last two years the UK’s world-renowned academics and industrial labs have, with few resources and scant government support, overtaken the USA and the rest of the EU in thorium R&D.

The UK will lose its early lead in this growing field if greater support for thorium R&D is not forthcoming. Despite strong objections from the Lords, current policy fails almost entirely to support nuclear R&D, which is the lifeblood of this industry. As we noted in our recent letter to the Daily Telegraph, the reactor R&D budget has suffered a swingeing 99% cut in the past 20 years. We should consider how many new lifesaving drugs would have been brought to market in the last 20 years if the life-sciences budget had been cut by 99%. The answer is: not many.

Nevertheless the last 12 months have witnessed a great surge in private sector-led nuclear R&D, with many very promising reactors breaking cover. Programmes of research and development are urgently needed to enable UK organisations to take a lead in commercialising the many next-gen reactor concepts now in development around the world.

With both Lords’ and MPs’ Inquiries ringing in its ears, the Government must resolve to revitalise the UK nuclear industry with a renewed focus on R&D, and to make the UK the pre-eminent international hub for research into thorium-fuelled reactors.

Merry Christmas and Happy New Year to all our readers.

Negotiations about Iran's nuclear plans

By U.S. Department of State from United States [Public domain], via Wikimedia Commons

The recent agreement between six world powers and Iran has, according to President Obama; “cut off Iran’s most likely paths to a bomb”The agreement includes many commitments to cease enrichment of uranium above concentrations of 5%, dismantling or halting construction of additional centrifuges and a pledge to not construct a reprocessing facility. Iran will continue to enrich uranium to concentrations of 3.5% to keep its stocks at a constant level as it is consumed in the civilian nuclear power program.  

However, much of the discussion about the deal has missed one key question: the extent to which we are made prisoners by the proliferation risks of existing fuel cycles. Could a programme of nuclear R&D, aimed at developing proliferation-resistant nuclear energy, prevent future nuclear crises?

What if we said that no enrichment facilities would be necessary if Iran was planning on producing nuclear energy with a thorium fuel cycle?

Thorium sits two places down the periodic table from uranium, and while very little of naturally occurring uranium is the U235 necessary for use in a reactor, almost all of naturally occurring thorium is Th232, which is the isotope suitable for use as a nuclear fuel. . Because of this, there is no need for any enrichment of thorium fuel and no need for centrifuges of any kind. The lack of any need for these facilities would certainly change the game in terms of detecting rogue nuclear programmes.

However, there is a “but”: thorium fuels need a “fissile driver” to provide the initial neutrons to start the thorium chain reaction. This can be uranium-233, uranium-235 or plutonium, although for anti-proliferation purposes we should certainly discount the last two.

So that leaves us with U233. Handily, uranium-233 is produced by thorium fuels in a reactor (in a thorium fuel cycle, it is actually uranium-233 that fissions). The rub is that the world has very little U233 available and if we want to develop proliferation-resistant fuel cycles, we’ll need a lot more of it. Currently the only way to make it is to kickstart thorium fuel with…U-235 or plutonium, and then reprocess it (although Accelerator-Driven Systems could help).

Proliferation resistance

While U233 is recognised as a proliferation risk by the IAEA, it is far less suitable for making weapons than highly enriched U235 or Pu239. Indeed, only two nuclear tests have involved U233; the USA’s ‘Operation Teapot’and one 0.2kt experimental design in India’s Pokran-II tests. No nuclear weapons in existence are made with U233. Sadly uranium-235 and plutonium have a well-proven track record of making functioning bombs.

U232 is produced in smaller amounts alongside the U233, which is a hard gamma ray emitter. This gives the material a strong and easily detectable radiation signature. The material has to be handled very carefully, and fuel fabrication for example has to be done remotely with sophisticated equipment. These increased difficulties have long been cited as  properties that would hinder weapons proliferation.

Hans Blix, the former head of the International Atomic Energy Agency has recently called for the development of nuclear energy from thorium, citing a lower risk of weapons proliferation from reactors as well as benefits including reduced waste. He wrote in the Guardian newspaper that the commitments were “constitute substantial bars to any bombmaking” without curtailing the civilian power program. I’m sure he would agree that if Iran was pursuing thorium-fuelled reactors, the barriers to a weapons program would be even higher.

Of course, how any future international thorium fuel programme would obtain and distribute the “fissile drivers” would be very sensitive, needing just the kind of increased transparency and oversight that has just been agreed. What is certain is that proven thorium fuels, started with U233, would give the international community new diplomatic options in future nuclear disputes.

The nuclear club is expanding

Thirty-one of the world’s countries currently use nuclear power to generate over 11% of global electricity. Over forty-five countries are considering embarking down the nuclear route, with the front-runners after Iran and UAE including Lithuania, Turkey and Belarus. It is important to stress that thorium is not a magic bullet to weapons proliferation– but it can be a part of the solution to future international proliferation disputes, alongside appropriate regulatory regimes and oversight mechanisms. Given the pressing need for low-carbon energy it seems only prudent to support a more proliferation-resistant route for nuclear energy.

The MegaTons to MegaWatts program which saw almost 20,000 Russian warheads dismantled and used as fuel in American nuclear power plants has recently come to an end, providing almost 10% of US electricity for 15 years. A similar amount of warheads remain in existence. In 1953, Eisenhower’s ‘Atoms for Peace’ speech carefully tried to open the eyes of the world to the positive benefits of nuclear energy, after the horrors of the nuclear bomb had become clear. He urged that “the miraculous inventiveness of man shall not be dedicated to his death, but consecrated to his life”. Perhaps it is time for that speech to be revisited, starting with a massive push to develop proliferation-resistant nuclear energy.

HuXongjie AnilKakodkar IndiaTHEC13 Dinner

China’s Xu Hongjie (r) and India’s Anil Kakodkar chat after dinner at the Thorium Energy Conference in Geneva this week. Xu leads China’s TMSR programme. Kakodkar, former chairman of India’s Atomic Energy Commission and one-time head of the country’s Bhabha Atomic Research Centre, champions thorium use in his country.

GENEVA – Thorium-fueled high temperature reactors could help alleviate China’s energy and environmental problems – including water shortages – by providing not only low carbon electricity but also clean heat for industrial processes and power for hydrogen production, the scientist in charge of developing the reactors said here.

Xu Hongjie of the Chinese Academy of Sciences (CAS) in Shanghai indicated that one of the two reactors he’s developing should be ready in a 100-megawatt demonstrator version by 2024, and for full deployment by 2035. A second one, based on liquid thorium fuel instead of solid, would come later, he said, hinting that it might not yet have full government financial backing.

In a presentation at the Thorium Energy Conference 2013 (ThEC13) here, he referred to both reactors as thorium molten salt reactors (TMSR). The solid fuel version uses “pebble bed” fuel – much different from today’s fuel rods – and molten salt coolant. The liquid version uses a thorium fuel mixed with molten salt. Both run at significantly higher temperatures than conventional reactors, making them suitable as industrial heat sources in industries such as cement, steel, and oil and chemicals. The thorium can also reduce the waste and the weapons proliferation threat compared to conventional reactors.

“The TMSR gets support from the Chinese government, just because China is faced with a very serious challenge, not only for energy, but also for the environment,” Xu said. He noted that several regions of China face water shortages in large part because China’s many coal-fired power plants require water for for cooling, as do China’s 17 conventional nuclear reactors.

“Water scarcity is very serious for China,” he said. “Most of the water has been consumed by electricity companies – for coal but also nuclear.”


Nuclear reactors will help slow the growth of China’s CO2 emissions. The country today gets about 80 percent of its electricity from CO2-spewing fossil fuels. As China ramps up generating capacity to an estimated 3,000 gigawatts by 2030 – more than double today’s level – it will need to find low-carbon sources to mitigate climate change consequences.

Xu is the director of CAS’ of Thorium Molten Salt Reactor (TMSR), based at the Shanghai Institute of Applied Physics, overseeing what he said is a $400 million project (China has described it in the past as $350 million). He calls the solid fuel reactor a “TMSR-SF,” and the liquid reactor a “TMSR-LF”.

One of two timelines (see below) that Xu included in his presentation showed that he expects to complete a 2-megawatt pilot for the solid fuel version by around 2015, and a 100-MW demonstrator model of the same by 2024, before readying it for live use in 2035 in “small modular” form (general industry nomenclature would call the solid fuel version an “FHR”, or fluoride salt-cooled high temperature reactor).

That timeline did not show a target date for a 2-MW liquid-fueled pilot reactor, which a year ago appeared to have slipped from 2017 to 2020. It did, however, show a 10-MW liquid-fueled pilot at around 2024, and a demonstrator version by 2035. It did not include a commercialization date. “For liquid, we still need the financial support from the government,” Xu said (story continues below chart).

XuHongjie TMSR Timeline

Solidifying the future. The solid fuel (TMSR-SF) molten salt cooled thorium reactor will be ready before the liquid fuel model (LF).

Xu explained that the liquid version requires more complicated development than the solid version, such as “reprocessing of highly radioactive fuel salts.” But the reprocessing, when worked out, will become an advantage because it will allow re-use of spent fuel, whereas the “open” fuel cycle of the solid version will not, he noted. Xu said that the solid fuel version is a “precursor” to the liquid-fuel reactor.

A second timeline showed plans for developing larger TMSRs, with a 1-gigawatt capacity. It showed “commercialization” for the solid fuel version by around 2040, when the liquid 1-GW machine would reach a “demonstrator” state. The timeline does not show commercialization plans for the 1-GW liquid version. It does, however, show that a 2-MW “experimental” liquid TMSR could by ready by around 2017 (story continues below chart).

XuHongjie 1GW TMSR Timeline

This slide, part of Xu Hongjie’s presentation, shows the timeline for a large TMSR, and suggests it would be used for hydrogen production.

After his presentation, I asked Xu to clarify the difference between the two timelines and the state of government financing, but he declined.

The second timeline shows the 1-GW reactors going to work for hydrogen production, a process that China mentioned at last year’s conference, held in Shanghai. Xu reiterated that China would combine hydrogen with carbon dioxide to form methanol, a clean energy source.


China has also talked about using TMSRs for coal gasification, and to convert coal to olefin and coal to diesel.

Xu told me the TMSRs would be used for electricity generation as well, although one slide in his presentation notes that the aim is to develop “non-electric” applications. Earlier this week at the conference, Nobel prize winning physicist Carlo Rubbia repeated an observation of his from a few years ago that China could generate the 2007 equivalent of its total electricity production – 3.2 trillion kWh, using a relatively small amount of thorium.

With those ambitious plans and with the program currently funded at around $400 million, Xu suggested that at some next stage the TMSR program will need an extra $2 billion “for the whole alternatives.”

China is collaborating with the U.S. Department of Energy on the molten salt-cooled reactor, which is the only publicly declared MSR programme in the world with funding in the hundreds of millions of dollars.

The four-day ThEC, which ended on Thursday, included a clarion call from former UN weapons inspector Hans Blix for thorium fuel as an anti-proliferation choice, and an equally loud entreaty by Rubbia who said thorium has “pre-eminence” over uranium, the conventional nuclear fuel. One big uranium devotee, nuclear giant Areva, announced a thorium collaboration with Belgian chemical company Solvay.

The conference, on the campus of international physics lab CERN, featured lively discussions of how best to deploy thorium, including driving them with particle accelerators, and using uranium isotopes to start a thorium fission reaction.

Photo of Xu Hongjie and Anil Kakodkar is by Mark Halper.

Charts are from Xu Hongjie’s ThEC13 presentation.

Hans Blix: Shift to thorium, minimize weapons risk

Posted by Mark Halper on October 29th, 2013

Hans Blix CERN THEC13

Thorium on his mind. Hans Blix says it’s time for the nuclear industry to move away from uranium.

GENEVA – Hans Blix, the disarmament advocate who famously found no weapons of mass destruction in Iraq a decade ago, said today that thorium fuel could help reduce the risk of weapons proliferation from nuclear reactors.

Addressing the Thorium Energy Conference 2013 here, Blix said that nuclear power operators should move away from their time-honoured practice of using uranium fuel with its links to potential nuclear weapons fabrication via both the uranium enrichment process and uranium’s plutonium waste.

“Even though designers and operators are by no means at the end of the uranium road, it is desirable today, I am convinced, that the designers and the others use their skill and imagination to explore and test other avenues as well,” Blix said.

“The propeller plane that served us long and still serves us gave way to the jet plane that now dominates,” said the former United Nations chief weapons inspector who also ran the International Atomic Energy Agency from 1981 to 1997. “Diesel engines have migrated from their traditional home in trucks to a growing number of cars and cars with electric engines are now entering the market. Nuclear power should also not be stuck in one box.”

Blix rattled off a list of thorium’s advantages, noting that “thorium fuel gives rise to waste that is smaller in volume, less toxic and much less long lived than the wastes that result from uranium fuel.” Another bonus: thorium is three to four times more plentiful than uranium, he noted.

“The civilian nuclear community must do what it can to help reduce the risk that more nuclear weapons are made from uranium or plutonium,” Blix said. “Although it is enrichment plants and plutonium producing installations rather than power reactors that are key concerns, this community, this nuclear community, can and should use its considerable brain power to design reactors that can be easily safeguarded and fuel and supply organizations that do not lend themselves to proliferation. I think in these regards the thorium community may have very important contributions to make.”

Blix described the obstacles that are in the way of a shift to thorium and other nuclear alternatives as “political” rather than “technical.”

Not everyone agrees that thorium is a proliferation cure for the nuclear power industry. Even some supporters of thorium note that thorium fuel cycles yield elements such as uranium 233 that groups could use to make a bomb if they were able to get a hold of it.

The lively discussions surrounding these and other thorium issues will continue tomorrow at the conference, which is taking place at CERN, the international physics laboratory. Earlier at the gathering today, conventional nuclear giant Areva announced a thorium collaboration with Belgian chemical company Solvay. Yesterday, Nobel prize-winning physicist Carlo Rubbia lauded thorium for its “absolute pre-eminence” over uranium.

Photo of Hans Blix by Mark Halper

Areva strikes thorium development deal with chemical giant Solvay

Posted by Mark Halper on October 29th, 2013

Areva LucVanDenDurpel CERN THEC13

If he were to look over his shoulder, Areva’s Luc Van Den Durpel would see the word “thorium.” With the metal gaining attention as an alternative to uranium fuel, Areva is now stepping up thorium research.

GENEVA – French nuclear giant Areva, a stalwart of the conventional uranium-driven large reactor industry, today announced it is collaborating with €12.8 billion Belgian chemical company Solvay to research the possibilities of deploying thorium as a reactor fuel.

“Solvay and Areva have made an agreement to have a joint R&D program working on the whole set of thorium valorization (validation),” Areva vice president Luc Van Den Durpel said in a presentation at the Thorium Energy Conference 2013 at the CERN physics laboratory here.

Van Den Durpel said the effort would cover “the overall worldwide development related to thorium, both in the nuclear energy field and in the rare earth market.”

Thorium, a mildly radioactive element that supporters believe trumps uranium as a plentiful, safe, effective, weapons-resistant fuel – Noble laureate physicist Carlo Rubbia yesterday referred to its “absolute pre-eminence” over uranium – comes from minerals that also contain rare earth metals vital the to the global economy. Solvay’s business includes rare earth processing, which can leave thorium as a “waste” product that’s subject to strict and costly storage regulations. Companies that have to hold on to thorium would like to find a market for it.

Ven Den Durpel said Areva and Solvay will investigate “resolving the thorium residue issues arising from certain rare earth processing in the past and now.”

As a possible nuclear fuel, he acknowledged that thorium offers advantages such as reducing waste and proliferation risks. “It’s not the devil – you could call it sexy because it’s not plutonium and that why it’s attractive,” he said in reference to uranium’s notorious waste product. He also noted that thorium’s high melting point provides operational advantages.

But the Areva executive, who heads strategic analysis and technology prospects in corporate R&D, said that any chance of Areva using thorium in a reactor is a long way off.

“We would like to demystify thorium,” he said, noting that its benefits are often overstated and hyped, and that it has issues including the management of radioactive isotopes of protactinium and uranium involved in the thorium fuel cycle.

He said there is “not really” a market for thorium in the short term, but that a “medium term” market is a “possibility” that would entail mixing thorium with other fuels like uranium and plutonium in light water reactors. By complementing the other two fuels, thorium could potentially lengthen fuel cycles, reduce waste, and produce uranium 233 for use in other reactors.

But he said any transition to 100 percent thorium fuels would “take decades at least.”

Ven Den Durpel based his thorium assessments on use in light water reactors, and not in alternative reactor designs such as molten salt reactors or pebble beds.

Photo by Mark Halper

Nobel laureate: Go thorium

Posted by Mark Halper on October 28th, 2013

Carlo Rubbia Geneva THEC13 Reception2

Carlo Rubbia, mixing with delegates at this week’s International Thorium Energy Conference, says thorium has “absolute pre-eminence” over other fuel types, including uranium and fossil fuels.

GENEVA – If nuclear power is to finally overcome public opposition and the post-Fukushima backlash, government and industry must walk away from traditional reactor technology and shift to superior designs that rely on thorium rather than uranium.

So said Nobel Prize winning physicist Carlo Rubbia this morning, addressing the Thorium Energy Conference 2013, held here at the renowned international physics lab CERN.

“In order to be vigorously continued, nuclear power must be profoundly modified,” said Rubbia, a former director general of CERN and the co-winner of the 1984 Nobel Prize in Physics.

Rubbia noted that thorium has “absolute pre-eminence” over all fuels including uranium as well as fossil fuels. He said it must become a staple of nuclear because it leaves less long-lived waste than uranium, is far more plentiful, is resistant to weapons proliferation and has a much higher energy content so that reactors will require less of it (see chart below).


Rubbia called for a shift toward thorium so that nuclear could play a big role as a low-CO2 energy source, a function that the public tends to associate with renewable energies like wind and solar.

“A distinction between renewable and not renewable energy is academic,” said Rubbia, who pointed out that the country most famous for CO2-spewing coal-fired plants, China, could generate the equivalent of its 2007 electricity production – 3.2 trillion kWh – by using an amount of thorium that is just a small percentage of China’s domestic production of rare earth metals. Thorium comes from minerals that also also contain rare earth elements, a class of materials that are vital to the world economy and that China controls.

MonaziteITHEC Geneva2013

Energy’s rock solid future. Thorium occurs naturally in minerals like this chunk of monazite from South Africa’s Steenkampskraal mine, on display at the Geneva conference.

Rubbia told a packed audience of thorium and reactor experts that thorium is probably also a superior fuel for reactors known as breeders, which produce more of their own fuel.

Thorium supporters differ over the best way to deploy the fuel. Speakers and enthusiasts from around the world are gathered here for four days to compare notes and advocate their own approaches.


Rubbia, a particle physicist, prefers a method in which an accelerator coaxes thorium to split by bombarding it with a neutron – a concept known as an “energy amplifier” which he helped conceive.

Unlike uranium, thorium is not “fissile.” It requires a method to kick start it, such as the accelerator approach or another technique that mixes it with an isotope of uranium that releases neutrons that in turn excite thorium.

Scientists and engineers also differ over whether to burn thorium in conventional reactors or in a number of alternatives such as molten salt reactors or pebble bed reactors, the designs for which date back decades. Both run at much higher temperatures than today’s reactors and thus support a more efficient generating cycle. They could also serve as a low-CO2 source of industrial process heat, replacing fossil fuels in operations such as cement and steel making.

Rubbia co-won the 1984 Nobel for work at CERN leading to the discovery of the W and Z bosons, which are related to the weak force, one of the four fundamental forces of nature along with the strong force, gravity and electromagnetism.

He is currently affiliated with the Gran Sasso National Laboratory in Italy as well as the Institute for Advanced Sustainability Studies in Germany. He was recently named a senator for life in Italy, where he previously ran ENEA, an energy and technology development agency where he promoted solar thermal power.

Other speakers followed Rubbia outlining their preferences for thorium and providing updates for thorium reactor initiatives in countries including China, Japan and India. Stay tuned the Weinberg blog for more reports.

Photos are by Mark Halper

EnergySourceJoules Rubbia CERN THEC

The Crown Joule. Thorium has a higher energy content than any other fuel including uranium, even uranium extracted from seawater (sw in the chart), according to this slide from Rubbia’s Geneva presentation.


Bill Gates TED Jurvetson Flickr

Opening the nuclear Gates. TerraPower, Bill Gates’ nuclear company, is now open to reactor types other than its traveling wave design. The traveling wave remains the company’s focus, although Terra has morphed it into more of a “standing wave.”

TerraPower, the Bill Gates-chaired nuclear company that is developing a fast reactor, is now  investigating alternative reactor technologies, including thorium fuel and molten salt reactors.

While the company’s “big bet” continues to be on a fast reactor that TerraPower calls a traveling wave reactor (TWR), it is exploring other designs that could offer improvements in safety, waste and economics, CEO John Gilleland told me in a phone interview.

“We are an innovation house, so we like to look at other approaches,” Gilleland said. “Our big bet is on the traveling wave reactor because it fulfills so many of the goals that we would like to see nuclear achieve. But we’re always looking for innovations that lead to better safety or minimization of waste and so forth and so we have several things going there. Although those activities are small, that’s the way large activities get started.”

TerraPower’s interest in alternatives such as molten salt reactors (MSRs) came to light last month when the company’s director of innovation, Jeff Latkowski, surfaced in the audience at the Thorium Energy Alliance Conference in Chicago. The two-day gathering included presentations on thorium fuel and on reactors including molten salt reactors, high temperature solid fuel reactors, accelerator driven reactors, and others.

Latkowski quietly joined the five-year-old Bellevue, Wash., company a year ago to look after alternative approaches to nuclear. “My job at TerraPower is everything outside the Traveling Wave Reactor,” Latkowski told me in an email exchange after the Chicago event.


That includes MSRs, the design known by its enthusiasts to efficiently and safely produce high temperature heat for electricity generation and for industrial processes. MSRs use liquid fuel that cannot melt down and that harmlessly drains into a holding tank in the event of an emergency. They operate at atmospheric pressure rather than at potentially dangerous high pressures associated with conventional reactors. MSRs augur improvements in waste and a reduction in weapons proliferation threats, especially if they run thorium fuel. Tennessee’s Oak Ridge National Laboratory built an experimental version in the 1960s, under the direction of Alvin Weinberg.

Another benefit for MSRs, as Gilleland noted, is that “your fuel is not as susceptible to the sort of neutron damage that other approaches are.” In other words, MSRs have a much higher “burn up” – they make greater use of fuel – than do conventional solid fuel reactors.

“We’re thinking about it and trying to work on it and we have a few proprietary ideas that we’re cooking up,” Gilleland said in relation to MSRs. He did provide details of the “proprietary” ideas, noting that, “We like to work on an idea for a while before we run out and tell about it – so we have some ideas which we’re trying to ferret out how good they are.”

Director of innovation Latkowski declined to say whether or not TerraPower has filed any MSR patents. In addition to running innovation and related partnerships, Latkowski also “oversees the development, maintenance and protection of TerraPower’s intellectual property portfolio” according to his company bio. TerraPower is a spin out of Intellectual Ventures, an innovation and venture capital firm that makes a business out of patents and is known as a keen collector and protector of intellectual property. It is headed by Nathan Myhrvold, a former Microsoft chief strategist and technology officer who serves as TerraPower’s vice chairman.

Nathan Myhrvold TerraPowerVideoYoutube

Patently speaking. TerraPower vice chairman Nathan Myhrvold is CEO of Intellectual Ventures, a company whose business is intellectual property. TerraPower is an Intellectual Ventures spin out. Above, Myhrovld describes the environmental merits of nuclear in 2011.

I asked CEO Gilleland about the extent to which TerraPower bases its MSR ideas on the Oak Ridge design. “Oh everybody goes back to that as a good reference point, and we have considerable departures from it that we’re thinking about,” he said. “So we’re just having a lot of fun with it. That’s how you get good ideas.”

According to Gilleland, MSRs still face technological hurdles, including the avoidance of corrosion in the reactor materials. He also said that TerraPower would want to assure that an MSR could reprocess fuel without having to remove it. Any removal increases proliferation possibilities of waste falling into the wrong hands. (One of the strong suits that TerraPower claims for its TWR is that, unlike other fast reactors, the TWR does not require the expensive and potentially hazardous removal of spent fuel to reprocess into usable fuel).

“We prefer a system where you can leave fuel in the reactor for a long time,” he noted.


TerraPower is also investigating the possibility of deploying thorium, a fuel that Gilleland said could trump uranium by virtue of thorium’s wider availability. There is about four times more thorium than uranium in the world.

But Gilleland noted that the attributes of TerraPower’s TWR fast reactor could offset any need for thorium. The TWR is the design that TerraPower has proposed for converting depleted uranium into plutonium that would burn for about 60 years before requiring refueling. It is a type of fast reactor – a reactor that does not slow down or moderate neutrons as today’s commercial “thermal reactors” do.

What about other nuclear technology alternatives, such as high temperature solid fuel reactors?

“We’re looking at all of them,” said Gilleland. “There’s no one at the top of our list right now.”

He described Latkowski’s innovation initiative as a “skunk works” that’s not a formal division but rather is a framework for encouraging lateral thinking. He likened it to innovative information technology companies that facilitate free thinking time for employees.

“It’s like Google and other places – the best ideas sometimes came from the person doing the backstroke in the swimming pool, or at home thinking,” said Gilleland. “So we want to just make sure that people have a certain fraction of their time for free thinking.”


One nuclear technology that TerraPower most likely won’t be pursuing is fusion.

“I have a soft spot in my heart for fusion, having run the ITER program and things like that, but it’s something I can’t count on for my grandchildren,” said Gilleland, whose background includes having served as U.S. managing director on the International Thermonuclear Experimental Reactor (ITER), based now in Cadarache, France. Innovation director Latkowski also comes from a fusion background. Before joining TerraPower last year, he was chief scientist on the commercialization program at the National Ignition Facility, the U.S.’s massive laser fusion project at Lawrence Livermore National Laboratory in California.

“We’re focused more on fission rather than fusion,” Gilleland said. “Fusion just takes so much more development and so much more time.” Other companies, like General Fusion, Helion Energy, Lawrenceville Plasma Physics, Tri-Alpha Energy and Lockheed Martin might disagree.

So how real are the company’s fission possibilities outside of the TWR?

“If we do things right , we’ll have some interesting things to talk about,” he said.

His interest in broadening nuclear development at TerraPower echoes remarks made in the past by TerraPower chairman and software billionaire Gates. In a 2010 presentation at the Massachusetts Institute of Technology, Gates pointed out that “nuclear innovation stopped in the 1970s”and encouraged the industry to move to alternative nuclear technologies.

Gilleland described reactors such as the MSR as “futuristic” compared to the traveling wave, noting the TWR will come out first. The company thinks the TWR can be ready by the mid-2020s.


Development work and partnerships on the TWR are progressing, and TerraPower has already made a notable design change. AlthoughTerraPower still refers to its reactor as a “traveling wave,” it has turned it into more of a “standing wave” design.

In a TWR, first proposed in the 1950s, a cylinder of depleted uranium burns slowly like a candle, breeding plutonium (in a breeding “wave”) which fissions and produces heat. But as the World Nuclear Association notes, TerraPower has, “changed the design to be a standing wave reactor, since too many neutrons would be lost behind the traveling wave of the previous design and it would not be practical to remove the heat efficiently.” (TerraPower’s design calls for removing heat with a liquid sodium coolant).

In the new standing wave design, the fission reaction starts “at the centre of the reactor core, where the breeding wave stays, and operators would move fresh fuel from the outer edge of the core progressively to the wave region to catch neutrons, while shuffling spent fuel out of the centre to the periphery,” WNA explains.

As Gilleland put it, “We decided to have the fuel move past the wave rather than have the wave move past the fuel.” (The neutron loss might help explain why Gilleland is attracted to the MSR’s tendency to avoid neutron damage).

“It’s basically the same physics of what we started out with,” he said. “It’s just the practical considerations associated with making the most use of every neutron, and the engineers’ love of keeping the cooling system in one place, and not chasing the wave. It didn’t set us back at all. It was just sort of a natural evolution and one of the variations on the theme we’d been studying all along and then we just finally decided to switch to this standing wave. It just made some things easier.”

TerraPower believes it can start up a 600-megawatt prototype reactor by 2022 and have its first fast reactor ready for deployment by the mid-2020s. To that end, it has entered development partnerships with many international and domestic research groups and companies. The partners include several outfits in Russia, a country that is emphasizing fast reactor development: state nuclear company Rosatom and its TVEL fuel group; the Scientific Research Institute of Atomic Reactors; and A.A. Bochvar High-technology Research Institute of Inorganic Materials.

In China, TerraPower has teamed with the China Institute of Atomic Energy, which is developing a fast reactor. Other partners include the Korean Atomic Energy Research Institute, Japan’s Kobe Steel. Domestically, TerraPower is working with, among others, MIT, the University of California Berkeley, Oregon State University, the University of Michigan, Texas A&M University, the University of Nevada and a number of private companies. For a full list see TerraPower’s “partners” page.

It will be interesting to see if any MSR partners begin to appear on the website.

Photo of Bill Gates talking about nuclear and the environment at a 2010 TED talk is by Steve Jurvetson, via TED and Flickr. Photo of Nathan Myhrvold is a screen grab from a TerraPower video via New America Foundation and YouTube.

NOTE: This version corrects an earlier one that stated the TWR performs online reprocessing. It does not. Its fuel does not require reprocessing. Not only does it not have to remove fuel for reprocessing – an advantage over other fast reactors – it does not have to reprocess at all.. Also, Jeff Latkowski was chief scientist for NIF’s commercialization program, called Laser Inertial Fusion Energy (LIFE), not for all of NIF as originally stated. Corrected July 24 at 3:10 p.m. UK time.

Joe Sestak TEAC5 2

In thorium we trust. Former Congressman Joe Sestak, who is considering a senatorial run in 2016, says    that liquid thorium reactors hold several keys to national security and the economy, including clean heat    for industrial processes.

CHICAGO – Thorium molten salt reactors could help underpin the nation’s economic and energy security, a former U.S. congressman, Navy admiral and senatorial candidate said here recently.

Joe Sestak, a determined Pennsylvania Democrat who is considering another run for the Senate in 2016, told the 5th Thorium Energy Alliance Conference that companies from heavy industries including fossil fuels should deploy thorium reactors as a source of clean, efficient and affordable heat to power high temperature processes.

Molten salt reactors (MSRs) in principle operate at around 800 degrees C, much higher than conventional nuclear reactors, making them suitable CO2-free replacements for today’s CO2-emitting fossil fuel furnaces. MSRs can be made in small sizes, so they would be easy to site on industrial locations.

Sestak encouraged MSR developers – who typically promote the CO2-free benefits of their technology – to pair with the “strange bedfellows” of  CO2-emitting hydrocarbon companies that could fund MSR development and use the finished reactors to support and clean up their own industrial processes.

“You have got to get allies on board,” Sestak told a crowd of scientists, business people and others who were full of enthusiasm and plans for thorium, MSRs and other high temperature designs, but who generally lack the funds to develop and build their reactors. “The best ones are unlikely bedfellows.”


Thorium reactors could help establish American energy independence by propping up the natural gas fracking business that is prevalent in Sestak’s home state of Pennsylvania and that is helping reduce the country’s reliance on volatile and expensive imports of fossil fuel, Sestak noted. Producers of natural gas and coal could use the reactors for extraction heat and for clean processing of gas and coal into liquid form.

Other industries that could benefit from nuclear heat include concrete, fertilizer and hydrogen production, as well as water desalination Sestak said. He noted that reactors like MSRs have “an immense role to play if you focus on heat processes.”

Showing an astute awareness of thorium resources and value chains, Sestak noted that thorium naturally occurs in the same minerals as rare earth metals that are vital across a swath of industries. Manufacturers build rare earths into everything from missiles to medical equipment to cars, cellphones and computers, just to name a few; the list also includes renewable energy gear such as wind turbines and solar equipment.

Mining those rich minerals – such as monazite – could not only yield useful thorium, but would also provide the country with rare earths, helping to ease China’s dominance of  them and supporting domestic manufacturing Sestak said. He noted that China controls 97 percent of the rare earth market. They exist underground in the U.S.; production and exploration is only now slowly returning, some two decades after stricter environmental regulations caused domestic producers to shut down.


In a virtuous circle, Sestak added that rare earth extraction would also further support the country’s energy supply because, solar, wind, nuclear and fossil fuel equipment all rely to some extent on rare earth components.

“We have to be very clear that molten salt reactors or whatever we come forward with does not pose a threat (to other energy sources),” he said. “Rather, it will enhance and make cleaner and give more utility for other types of energy.”

Equating energy and economic stability to national security, he noted that, “For me, this issue of thorium with rare earth minerals has to be looked at as a national security issue. I believe that thorium, with rare earths is a way to enhance – greatly – the accessibility of our energy in so many fields, not just nuclear power.”

His ideas echo the Thorium Energy Alliance’s proposals for an international “Thorium Bank” cooperative that would oversee the safe handling of thorium – a mildly radioactive substance – and help facilitate production and distribution of rare earths from the same minerals. The Organisation of Rare Earth Exportation Companies is pushing for something similar.

Sestak has experience in trying to work thorium onto the national agenda. As a two-term Philadelphia area member of the House of Representatives from 2007 to 2011, he wrote an amendment supporting thorium reactors into a defense bill that passed the House but did not survive the Senate.


He could get another chance to push thorium from within Washington, as he is considering running for Senate in 2016.

Sestak ran a bold Senatorial race in 2010 when he defied his party’s wishes and challenged fellow Democrat Arlen Specter for the party candidacy, and won. He narrowly lost the main election to Republican Pat Toomey, whose campaign greatly outspent Sestak’s.

Sestak spent over 30 years in the U.S. Navy, rising to three-star admiral, and retiring in 2005. He commanded the USS George Washington nuclear powered aircraft carrier in Persian Gulf and Indian Ocean in 2002, supporting the war in Afghanistan and monitoring Iraqi airspace. During his naval career, he also served as Director for Defense on the National Security Council for the Clinton administration, and served as director of the Navy’s “Deep Blue” counter-terrorism unit after the Sept. 11, 2001 attacks.

The former Congressman told the conference that he has solid trust in nuclear safety, noting that in his days commanding nuclear craft, “I put my head down at night about a hundred feet from that reactor.”

Sestak currently teaches at Cheyney University near Philadelphia and is an adjunct professor at Carnegie Mellon University in Pittsburgh, where he teaches courses in ethical leadership and in restoring the American dream.

Perhaps that restoration should include thorium molten salt reactors. 

Photo: Joe Sestak at the Thorium Energy Alliance Conference by Mark Halper.

Note: This is the first of several reports about the lively proceedings in Chicago, where presentations spanned new thorium reactor types, surprising corporate interest in thorium, coolant safety, MSRs as medical isotope sources, thorium on Mars and much more ranging from the practical to the thought provoking. Stay tuned…

Geoff Parks Horse

Riding the thorium trail. Cambridge senior lecturer Geoff Parks believes actinides could recycle for a long, long time when mixed with thorium in a modified light water reactor.

Thorium mixed with plutonium and other actinide “waste” could continuously power modified conventional reactors almost forever in a reusable fuel cycle, according to a discovery at the University of Cambridge in England.

The discovery, by PhD candidate Ben Lindley working under senior lecturer Geoff Parks, suggests that mixed thorium fuel would outperform mixed uranium fuel, which lasts only for one or two fuel cycles rather than for the “indefinite” duration of the thorium mix.

Ideally, the reactors would be “reduced-moderation water” reactors that work on the same solid-fuel, water-cooled principles of conventional reactors but that do not slow down neutrons as much and thus also offer some of the advantages of fast reactors.

Lindley’s finding, made while he was a master’s candidate in 2011, bodes well for the use of thorium not only as a safe, efficient and clean power source, but also as one that addresses the vexing problem of what to do with nuclear waste from the 430-some conventional light water reactors that make up almost all of the commercial power reactors operating in the world today and that run on uranium.

By mixing thorium with “waste” in a solid fuel, the nuclear industry could eliminate the need to bury long-lived plutonium and other actinides.

Lindley’s work surfaced recently in an article about it in the hard copy edition of Cambridge’s quarterly Engineering Department magazine. An earlier version also appears online.


I interviewed Lindley and Parks recently after the magazine story appeared. They explained the crux of Lindley’s discovery: Uranium/plutonium lasts for only a limited period because after one or two cycles, when the actinide portion increases, the mix displays a “positive feedback coefficient.” In the sometimes counter intuitive world of nuclear engineering, a positive feedback is an undesirable occurrence. To use an unscientific term, the reaction goes haywire.

Parks notes that with uranium, “As the amount of actinides in the mixture increases, you get this tipping point where with the uranium mixed with actinide based fuel  – a key feedback coefficient goes from being negative to being positive, at which point the fuel is not safe to use in the reactor.”

Lindley completes the thought. “The idea is that mixing things with thorium rather than with uranium keeps the feedback coefficient negative,” he says.

In a mixed fuel system, reactor operators would allow a batch of fuel rods to stay in a reactor for about five years, roughly the same as with today’s solid uranium fuel. The fuel would then cool for a few years while the shorter-lived fission products decay, and would then be reprocessed over another year, mixing actinide wastes with more thorium before being put back in a reactor.

And just how long could this cycle continue? “You could just keep doing that forever – until the world runs out of thorium,” notes Parks.

Ben Lindley

Wasting his future. Cambridge PhD candidate Ben Lindley made the discovery that actinide waste will     burn with thorium for an indefinite period, auguring a way to simultaneously generate power and dispose   of nuclear waste.

Lindley’s proposal is the latest possibility to emerge for using thorium reactors to dispose of waste as well as generate power.

As we wrote here recently, Japan’s Thorium Technology Solution (TTS) is proposing to mix thorium and plutonium in a liquid molten salt reactor.  Likewise, Transatomic Power in the U.S. has similar plans, although it is starting first with a liquid mixed uranium fuel rather than with thorium.

Lindley and Parks’ idea differs from TTS and Transatomic in one obvious way: It would allow the nuclear industry to carry on building conventional solid fuel, water-cooled designs. That would be strictly true only in the initial implementation of the technology, which Lindley and Parks say would entail thorium mixed only with plutonium rather than also with other actinides like neptunium, americium and curium. That’s because plutonium is now available from sources such as the Sellafield nuclear waste site in Britain. The other actinides are not as readily available, but would become so as it became clear they could be used as part of a mixed thorium fuel, Lindley and Parks believe.


Once the other actinides enter the mix, the optimal reactor would be a light water reactor modified to have less water and thus less moderation of neutrons in the reaction process. That, in turn, would allow more burn up of actinides.

Lindley envisions a reactor with about a quarter to half the amount of water as in a conventional LWR – enough to serve as a necessary coolant, but little enough so that the water could not slow down neutrons to the extent they do in a conventional reactor.

“It’s not really a fast reactor, and it’s not really a thermal (conventional) reactor,” notes Lindley. “It’s between the two.”

Hitachi, Toshiba, Mitsubishi Heavy Industries and the Japan Atomic Energy Agency all have reduced-moderation water reactor designs (RMWR), according to the International Atomic Energy Agency.

Lindley described them as similar to LWRs but with different fuel assemblies.

The development – and regulatory approval – of RMWRs is one of several challenges facing the deployment of mixed thorium fuel in a water-cooled reactor.

Another is the development and cost of reprocessing techniques for thorium and for actinides other than plutonium (for which reprocessing already exists).

“Splitting thorium from waste or splitting some of the minor actinides from waste has not been done on an industrial scale,” notes Lindley. “There are processes that are envisaged that can do that, that have been tested on a laboratory scale, but never on an industrial scale.”

Another hurdle: Fabricating fuel that as Lindley notes would be “highly radioactive” given the amount of waste that would go into it. “That would have to be done behind a shield,” Lindley says.

Reduced Moderation Water Reactor JAEA

“Light water Lite.” Lindley’s proposal to mix thorium with plutonium and other actinides would work best in   a reduced-moderation water reactor. The diagram above shows a uranium version of an RMWR, from the Japan Atomic Energy Agency.

All of that will require significant research and development funding –more than what Lindley currently has at his disposal, which consists of university research funds and academic scholarships.  One possible source for additional funding could be Cambridge Enterprise, a commercial arm of the university.

U.S. nuclear company Westinghouse has also been collaborating with Lindley on his thorium research. Lindley hopes to test his fuel at the Halden test reactor in Norway, where Westinghouse is a partner in Thor Energy’s project to irradiate thorium/plutonium fuel.

It will be interesting to see if any of the £15 million that the UK government recently earmarked for nuclear R&D finds it way to Lindley’s project. It’s possible that Sellafield could at least provide plutonium.


Given the potential usefulness of thorium as a way of ridding the UK of actinides, it’s not out of the question that funding could also come from the UK’s Nuclear Decommissioning Authority, which has a 2013-14 budget of £3.2 billion and which is responsible for managing nuclear waste, including actinides and shorter lived fission products.

As Parks notes, an ultimate goal for applying Lindley’s discovery “is to come up with a nuclear fuel cycle where the only waste you have to dispose of  is the fission product waste.”

Parks encourages the government to “grasp the nettle” and financially back the thorium research. He and Lindley note that a multiple-cycle thorium reactor would save money in the long run for among other reasons: uranium prices, although low now, will rise; and a mixed thorium/actinide fuel would eliminate costs associated with nuclear waste storage.

“There are economic benefits in the future to investing in the reprocessing and fuel fabrication aspects now,” says Parks. “And you would completely change what nuclear waste means as far as the public is concerned, in terms of the volume of it and how long it’s radioactive for.”

Lindley and Parks say that their technology could take hold in a commercial RMWR within 10-to-20 years.

For that to happen, they’ll have to find the right mix of collaborators and financial backers.

Photos from Geoff Parks and Ben Lindley. RMWR diagram from Japan Atomic Energy Agency


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