Posted by Mark Halper

Prime Minister David Cameron addressing an international summit of energy secretaries in London earlier this year. That’s UK Dept. of Energy (DECC) boss Ed Davey next to him, followed by U.S.chief Steven Chu and DECC minister Greg Barker. Thorium is slowly entering DECC’s clean energy radar.

Welcome again to the Weinberg Foundation blog, aka The Thorium Trail, where as we announced here yesterday, we will provide a steady stream of updates on the future of energy: Safe, peaceful nuclear power that cuts the CO2 cord and eases climate change. We will trot the globe looking at developments in thorium fuel, molten salt reactors and many other alternative nuclear technologies that are safer and more efficient than the uranium, water-cooled designs that have defined the industry for half a century.

Our first full post comes from the UK, where earlier this month the government’s Department of Energy and Climate Change published a curious report on thorium – a fuel that did not, at first glance, seem to impress DECC as a promising replacement for uranium.

A quick read of DECC’s Comparison of thorium and uranium fuel cycles looks almost dismissive.

“Thorium has theoretical advantages regarding sustainability, reducing radiotoxicity and reducing proliferation risk,” the executive summary states. “While there is some justification for these benefits, they are often over stated.”

Not exactly a ringing endorsement of the fuel that could minimize long lived dangerous waste, mitigate weapons proliferation, eliminate meltdowns, and run more economically than today’s uranium reactors.

The muted assessment, prepared for DECC by the National Nuclear Laboratory (NNL) – a privately run vestige of the defunct uranium stalwart British Nuclear Fuels Limited – notes that “the thorium fuel cycle at best has only limited relevance to the UK.” It concludes that the claim that thorium is inherently safer than uranium  “is not sufficiently substantiated and will not be for many years, if at all.”



But here’s the curious bit: We know here at the Weinberg Foundation that NNL is indeed more open to thorium than its conclusions suggest. We recently visited NNL at their headquarters in Sellafield, England, where they were clearly interested in learning more about thorium technologies, such as those under development in China including a molten salt thorium project.

And as we read beyond the report’s headline coolness, we spot plenty of encouragement. While downplaying thorium, the summary points out that “Nevertheless, it, is important to recognise that world-wide there remains interest in thorium fuel cycles and as this is not likely to diminish in the near future. It may therefore be judicious for the UK to maintain a low level of engagement in thorium fuel cycle R&D by involvement in international collaborative research activities.”

Judicious indeed!  Because as DECC/NNL itself spells out, thorium, while having “limited relevance,” also proffers many advantages over uranium.For instance, the report says thorium can operate more efficiently than uranium. “The thorium fuel cycle is in principle capable of achieving higher conversion ratios in thermal reactors than uranium fuel, which is advantageous for resource availability,” it states, adding that thorium “converts” into fissile material at nearly twice the rate that occurs in the uranium process.

Out with the old, in with the thorium? With Cameron’s government struggling to find backers to replace reactors such as this relic at Oldbury-on-Severn, now’s a good time to consider alternatives like thorium.


It notes that thorium leaves behind much less nasty waste, pointing out that it “generates only trace quantities of plutonium and higher actinides, which can reduce the long term radiotoxicity of spent nuclear fuel.”


DECC even begins to describe how difficult it can be to fabricate a bomb from the thorium fuel cycle, thus giving credence to claims by thorium supporters who say that thorium can eliminate the weapons proliferation risk. DECC notes that the thorium process includes traces of uranium 232, a substance so full of gamma ray emissions that no terrorist would survive contact with it in the first place.

Certain alternative reactor designs would draw out these advantages more than conventional water-cooled nuclear plants. DECC is particularly keen on very high temperature gas reactors (VHTRs), which tend to be gas-cooled. It also notes that thorium fuel could mix with plutonium and help the UK dispose of its troublesome stash of that deadly stuff.

So how is it that despite acknowledging all these benefits, DECC concludes that the thorium case is generally “overstated” and of limited relevance to the UK?

In part, by issuing a few specific refutations. For instance, on proliferation, DECC says that an intrepid bomb maker can circumvent the deadly U232. It concludes that the justification for thorium reducing proliferation risks “is not very strong.” (Of all the claims for thorium’s advantages, the proliferation argument is perhaps the most debated, and we welcome your comments and feedback on this or any other aspect).


But each time we read through the report, it strikes us that the main impediment to tapping thorium’s potential is, as DECC sees it, economics – the lack of funding to advance thorium development into a commercial state.

Or to put it another way, the entrenched British (read Western) nuclear industry – the half a century year-old uranium value chain – will not make the necessary investments to migrate to a superior technology when iterative improvements on conventional reactors will suffice.

That’s the sort of ossified thinking that got Big Media and Telecom in trouble as the Googles and Skypes came along.

To be clear, DECC did not exactly phrase it that way.  “While economic benefits are theoretically achievable by using thorium fuels … in current market conditions the position is marginal and insufficient to justify major investment by utilities,” it says.

“The thorium fuel cycle is disadvantaged because all the supporting infrastructure would have to be established from scratch,” it adds. “Furthermore, since the energy market is driven by private investment and with none of the utility companies investing or currently developing either thorium fuels or thorium fuelled reactor concepts, it is clear that there is little appetite or belief in the safety or performance claim.”


Meanwhile, China has no such investment reluctance. It has a bevy of alternative nuclear research projects underway, including several thorium initiatives. In one, the Chinese Academy of Sciences’ Shanghai Institute of Applied Physics has committed 400 experts and $350 million to building a small test thorium molten salt reactor by 2017 (we’ll bring you more about this in another post soon).

The DECC report can be read as an endorsement of thorium, but as a carefully worded, reluctant one in the face of a dominant uranium industry and in light of the government’s efforts to rescue plans to build new reactors with money from the uranium industry.

It’s no wonder then that DECC recommends at least “a low level of engagement” with international thorium efforts. “This will enable the UK to keep up with developments, comment from a position of knowledge and to some extent influence the direction of research. Participation will also ensure that the UK is more ready to respond if changes in technology or market forces bring the thorium fuel cycle more to the fore,” it says.

Or as someone recently commented,  it might also leave the country in a position to one day – soon even –  have to license thorium technology from the East.

Photos: Cameron et al, from DECC. Oldbury nuclear plant from David Bowd-Exworth via Wikimedia Commons.

Note: An earlier version of this story referred to NNL as “privatized.” NNL is “privately managed” by Ohio-based Battelle Memorial Institute, services firm Serco and the University of Manchester. The UK government owns it.


  1. David LeBlanc says:

    DECC even begins to describe how difficult it can be to fabricate a bomb from the thorium fuel cycle, thus giving credence to claims by thorium supporters who say that thorium can eliminate the weapons proliferation risk. DECC notes that the thorium process includes traces of uranium 232, a substance so full of gamma ray emissions that no terrorist would survive contact with it in the first place.

    Well you asked for comments, OK then, hogwash.

    By repeating this myth that contact with a bomb pit amount of uranium 233 would have enough gamma radiation due to U232 to kill someone almost instantly and thus this somehow “eliminates” proliferation risk you open the door for people to doubt the many true claims of how good Molten Salt Reactors really are. Also please don’t paint a label on all “thorium supporters” as making such claims as it is only a small minority.

    U232 does add significant anti proliferation benefits but making such wild statements is helping no one. The gamma ray emissions come from U232 daughter products and those take months to build up in strength and even at their worst a bomb pit would take days to build up a fatal dose if one was a meter or so away from it.

    David LeBlanc

    • George R. Langworth says:

      Attaboy, David. Von Hippel and Kang’s paper should be reviewed by the author: “U-232 and the Proliferation-Resistence of U-233 in Spent Fuel,” Jongmin Kang and Frank N. von Hippel, SCIENCE & GLOBAL SECURITY, VOLUME 9 PP 1-32 © 2001 TAYLOR AND FRANCIS 0892-9882/01. Also, to circumscribe the matter, “U232 Nonproliferation Features,” Ralph Moir, June 23 2010, LLNL-TR-438648

  2. Joe Lambert says:

    I attended the Richard Martin presentation at the House of Commons on 19th June and suggested to Sophia Henri that you might contact SONE – Supporters of Nuclear Energy, You have probably done this already. SONE (www.sone in the person of its ebullient Secretary Sir Bernard Ingham has commented on occasion in Newsletters on thorium and the thorium vs uranium debate. See for example Newsletter 156 from September 2011 where he also says something interesting about Baroness Worthington. SONE has its AGM in London on 22nd October, it is always lively. I suggest someone from the Foundation attend and give an update on its activities. I would personally like to see SONE take more interest in thorium.

  3. Barrie Lee says:

    I was most disappointed to read the National Nuclear Laboratory report on the comparison of thorium with uranium nuclear reactors. It quite rightly looked at using thorium in existing reactors designed for uranium and, not surprisingly, found plenty of limitations and a few moderate gains.

    However the real advantages of thorium can only be realised in reactors designed specifically for it, but the report’s conclusion seemed to muddy, dilute and generally obscure this point by the problems of using it in uranium reactors.

    This is not at all my field but, to name one example the liquid salt version of the purpose built thorium reactor seems to have amazing potential for safety, low cost and mass production in the medium term.

    I would therefore advocate :

    1. Go ahead building uranium reactors as quickly as possible as already proposed. There is no doubt this poses a risk, but clever modifications to old designs and very careful risk analysis, with international design and build standards approved, and operational standards monitored by, for example, the IAEA should reduce this.

    Opponents should be reminded that climate change has already killed around 25,000 people in Europe in 2003, and, I believe almost 100 in America this year. I believe this is many times more than the total number of deaths from the previous three nuclear accidents. Cereal crops have also been very badly affected worldwide this year – and climate change will only get very, very much worse, and very quickly. The German reaction is illogical for these reasons.

    Because Climate change is so dangerous we simply cannot wait any longer. I and many others do not think we have decades left before we reach the tipping point, and I wonder why the governments of the world think we have.

    2. We and other nations should put significant effort into thorium reactor design and other renewables, because that will speed up the day when the cost of one or other, or both, drops down below uranium generators. That will remove the twin risks of countries abandoning or restricting nuclear use on either safety or economic grounds and (dare I say it) the temptation of some selfish countries to carry on using the very much more dangerous fossil fuels.

    Industry naturally doesn’t want to invest in this because they will not shoulder the cost of cleaning up uranium reactors and waste. That’s borne by the government. Countries which do develop thorium reactors will have the design rights, and the better technology will then destroy the nuclear building industries of those countries which do not.

    That’s several reasons why the government has to much more pro-actively fund development of reactor s specifically designed for thorium, in collaboration with other countries such as China and America, whilst building uranium reactors in the meantime. This will be orders of magnitude cheaper than trying to deal with the effects of climate change, which beyond a certain point will prove impossible anyway.

  4. Martin Kral says:

    Is that really Dr. Steven Chu in your picture? The same Dr. Chu who is the US Secretary of Energy? Quick reference from DOE web site:

    You will not find thorium mentioned anywhere on the DOE web site. The US doesn’t have their energy policy right at this time, but I think it was Winston Churchill who stated, “they will get it right eventually”.

  5. Robin Gould says:

    The time for endless talk about building Thorium Reactors similar to the LFTR principle is past. Such plant can be built to tabletop size, as well as to power station size. In conjunction with all interested parties, I am raising funds to initiate The Thorium Energy Trust. The trust will collect funds via crowd funding to start employing the personnel needed to build a UK reactor as part of the commercial enterprise any sensible person would want, to phase out fossil fuel proliferation and its consequential climate change problem. We have the abilities and are going to use them
    Robin Gould

    • Walter Horsting says:

      Hi Robin,

      I am working with the Thorium Energy Alliance on a Federal Chartered Cooperative Thorium Development Bank PPP legislation. We can use funding to lobby in DC and Sacramento.
      Walter Horsting

  6. Aido says:

    The UK (or Enngland anyway) used to be at the forefront of cutting-edge technology. What happened? Anyone with half a brain can see that thorium is the way to energy independance from other countries. I despair.

  7. Breanne says:

    Hilarious. And I was just wondering who will take on the jobs when they start budliing these Nuclear Plants that are gaining momentum. I hope there are enough new generation people getting past the 140 character limit. Here’s a trial lesson in 140 charactersLFTR is Moltn Salt reactr that uses Th cycle to produz cheap, safe,nuke-bomb-free fuel & no waste. Write congress so the guys at the top know yur doing yor homework (135 characters)

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