On Monday, September 12, we took the tube to Euston Station and rode a high-speed train about 300 miles to the north, nearly to the Scottish border. We stopped in Penrith, a small town in Cumbria and the gateway to the beautiful Lake District of northern England. We stayed that night at a very nice little bed-and-breakfast that I thoroughly enjoyed, and ate at an Indian restaurant in Penrith, one of the few restaurants open that night.
Sellafield is a huge facility, perhaps comparable to the American nuclear complex in Hanford, Washington. It was here that the UK built its very first test reactors, and it was also here that they suffered their first nuclear accident. Sellafield (then called Windscale) was a site for gas-cooled reactors intended to generate weapons-grade plutonium using natural uranium and graphite moderator blocks. The first of the “Windscale piles” were built for this purpose. Later, reactors were built that were meant to integrate the plutonium production mission with electrical generation. These were originally called “PIPPA” (Pressurized Pile Producing Plutonium and Power). Pippa means something different in the UK now…
Much like the US site at Hanford, the mission to produce plutonium waned over the years and has now come to an end, but it left an awful hangover. Sellafield is predominantly a cleanup site, now, much like Hanford, and cleanup activities are consuming billions of pounds stirling per year. Compared to the decommissioning activities on the site, the National Nuclear Laboratory’s facilities are rather modest. They are very new and very modern, and this was where we spent all of our time while visiting Sellafield.
NNL leadership gave us an introductory briefing on the NNL, its history and capabilities, and then I presented on Flibe Energy and our efforts to design and build the LFTR. There were a number of questions about the processing technology used for the fluoride salt, and they were aware of some of the public claims we had made about thorium and challenged them. In particular, they challenged the notion that thorium could be consumed at high efficiency. It didn’t take long to realize that they were thinking in the solid-fuel paradigm. I spent some time explaining how the liquid fluoride fuel was impervious to radiation damage and already in the proper chemical form for the processing techniques that we propose to employ. Unlike solid oxide fuel, there is no need to dissolve in nitric acid or undertake separations processes where there are inevitable losses in each stage. Processing a FLiBeTh blanket salt to remove bred uranium-233 by fluorination leaves all the thorium behind and only extracts the uranium. I think that that was a new realization for them.
Having visited nuclear labs like ORNL, the feel of NNL’s facility was very similar. We met with several members of their staff including Kevin Hesketh, the lead author of the NNL position paper, “The Thorium Fuel Cycle” published in August 2010. As we left for the tour I took the opportunity to talk with Mr. Hesketh about his position paper. I asked why he wrote it, who had commissioned it, or why NNL had taken it upon itself to do so. He responded that they (NNL) had seen a lot of discussion about thorium on the internet and felt a need to quench what they saw as overactive enthusiasm on the subject of thorium. I said, “yes, our efforts on our blog are responsible for most of that enthusiasm, and it’s centered around use of thorium in liquid form in the liquid-fluoride reactor!”
I went on to ask Mr. Hesketh if he considered use of thorium in molten salt reactor such as the LFTR in his position paper. He responded that he had not, because he did not consider it a mature technology. I asked him why he did not then entitle his position paper “The Thorium Fuel Cycle in Solid Fuel” rather than the more expansive title that he chose, because he did not consider the thorium fuel cycle applied in liquid fluoride media. He responded that he had spent many years working for Westinghouse and was very familiar with AP1000 technology and solid-fuel fabrication, and felt that that was the only technology we needed going forward into the future. I challenged him on that point and asked how he could feel that solid-fueled, uranium-based technology was sufficient considering its very poor uranium utilization, but he was not concerned about that issue.
I suppose we would have to agree to disagree. He felt that thorium wasn’t very useful in solid fuels (a point that I do not disagree with) and that exploration of thorium’s potential in liquid fuels is not worthy of consideration because they are not mature technologies. I feel that the potential safety and performance benefits of thorium in liquid-fluoride reactors are so great that LFTR technology should be pursued with diligence and the commitment of resources. Mr. Hesketh is NNL’s main technical contact on the issue of thorium and future nuclear fuel cycles, so I don’t anticipate much change in position from NNL in the future.
We left the offices of the NNL and proceeded to walk to a nearby building where the NNL had built a facility for the fabrication and testing of solid oxide nuclear fuel, particularly mixed oxides of uranium and plutonium. The facility was immaculate, because as I later learned, it had never been used to make anything. There were rows of portable “hot cells” that could be docked into adapters that would allow force-augmented robotic arms to manipulate samples inside. I even got to “test-drive” one of the sets of robotic arms.
Next we saw an array of gloveboxes where powders of uranium, plutonium, or thorium oxide could be measured and sintered into pellets. These pellets would have then been transported to one of the hot cells where they would have been inserted, one by one, into a cylindrical tube of zirconium alloy cladding to form fuel pins. These fuel pins would then be arranged into fuel assemblies that would be loaded in a pressurized-water reactor to evaluate their performance under irradiation. It was all very impressive, but as I pointed out to my host, using liquid fluoride fuel pretty much made it all obsolete. We didn’t need to mix powders or sinter pellets. We didn’t need to load tubes or arrange assemblies, and we weren’t expecting swelling or cracking or bulk property changes in the fuel under irradiation. All of the data from the MSRE showed that fuel properties were impervious to radiation. My host’s response told me that he had not considered this before.
The facility was so clean you might have eaten off the floor but I was left with a pervasive sadness as to why none of this equipment had been used. I made inquiries of our host and he told us that any commercial entity that came in to use the facility would have to post a decommissioning bond on the order of £100 million to ensure that the facility could be decommissioned properly. I shared my opinion that £100 million is a awfully steep cost to find out if you want to make a few pellets of thorium oxide or plutonium oxide for testing. Despite the £300 million spent on the facility so far, I’m not optimistic that they will ever use it for the purpose for which it was designed.
We enjoyed the tour and the hospitality that NNL had showed us during our visit to Sellafield but I perceived that our nuclear ambitions were orthogonal to one another. NNL had invested heavily in solid-fuel and in the mechanisms for its fabrication, testing, and evaluation. They had, through Hesketh’s paper, staked out a public position that thorium was not worthy of further investigation. They were dimly aware of the possibilities of liquid fuel, and did not consider it significant enough to merit mention in their position paper.
We, on the other hand, saw thorium in the liquid-fluoride reactor as the key to a future of simpler, safer nuclear reactors. Our technology dispensed with the complications and expense of the fuel testing facilities we had seen at the NNL and I was very thankful for that. We had the potential to achieve vastly greater energy extraction efficiencies from the LFTR than would be possible by using thorium in solid form, even with repeated and expensive recycling steps. I was more convinced than ever that solid-fueled thorium reactors are a technological dead-end and that liquid-fuel was the hope of the future.
We drove back to Penrith and took the train back to London. As the sun set over the pastoral English countryside, I thought of the things that David MacKay had said to me a few days earlier in our meeting at DECC. He had described just how much of the land area of England would have to be covered with windmills, solar panels, and harvested for biomass in order to meet England’s energy requirements without the use of fossil fuels or nuclear power. As we sped past, I looked at the stone walls that held flocks of sheep. I thought of the generations and generations of people who had worked those lands, building those communities and creating something so beautiful to look at. Imagining it all replaced by biomass plantations or arrays of windmills filled me with a sickness.
We drove on and I saw a coal-fired powerplant, with its array of smokestacks pointing skyward. This was what we must replace, I thought, and the slow, solid-fueled strategy that the NNL and the British nuclear industry wants to take will never achieve it. The most they can hope for is to maintain a fraction of UK energy production as nuclear. But they won’t do anything to displace the coal.
The trip to Sellafield was very enlightening but ultimately very sad. We hope for help and support in our efforts to bring thorium energy to the UK but I doubt we will find it there. I certainly hope that I will be proven wrong.