Go Fast, Do More

I never dreamed less than a year after I set out to describe the potential benefits of new reactor technology to power sector emissions, South Australia’s economy and the future of abundant, reliable clean energy on Radio National’s Ockham’s Razor, that we would be in the midst of a royal commission into the nuclear fuel cycle, let alone witnessing a federal senator proposing a business case for a lucrative spent fuel bank and the power plant with which to consume it.

The full proposal has been announced at DecarboniseSA. I’m proud to say I modestly contributed.

With the right impetus and involvement, SA could start banking the foreign spent fuel in a purpose built facility relatively promptly. This would likely be in the form of dry casks containing used fuel assemblies, the safe handling and secure storage of which has been achieved in numerous countries. The fees for this service are potentially very large.

So. Casks on the pad, money in the bank. But what about the next step – the fast reactors that are needed to disposition this material? Not to mention provide zero carbon, potentially zero-cost electricity for the state, and significant employment.

The question is, how long will it take?

At this stage, the answer is it depends on who you ask.

On the one hand the Generation IV Forum considers sodium-cooled fast reactors to be the most promising modern design, with full deployment beginning after 2030. Commissioner Scarce himself was recently quoted as not expecting fast reactors to be available before 2040.

On the other hand, Dr Eric Loewen is the Chief Consulting Engineer for GE Hitachi, and he was asked about this in April at the Columbia School of International Public Affairs.

So again, on schedule… you have to see me the month after I get my licencing. That licencing effort is an unbounded risk, because I can’t tell you the time and the amount of resources we need to get through. …So if you look at what we did as a company in Japan with Advance Boiling Water Reactors – first-of-a-kind technology – we built those in thirty-six months.

As far as the engineer who’d like to build fast reactors in the UK is concerned, the uncertainty comes from the associated licensing process. With that complete, building the units should be as straightforward for his company as were the first ever Advanced Boiling Water Reactors in Japan.

On the gripping hand, Barry Brook is arguably this country’s foremost expert on the IFR, the Argonne fast reactor project that GE Hitachi now offers as PRISM. In Sustainable Technologies and Materials, April 2015, he and his co-authors observe:

It is imperative that we seek to displace our heavy dependence on fossil fuels over the coming decades with sustainable, low-carbon alternative energy sources that can provide reliable, economic baseload electricity and heat, and thereby mitigate the environmental damage of energy production and underpin global energy security and prosperity for a growing population and. So how best to proceed?

Here we argue that without an economically viable closed fuel cycle, there will be no dominant nuclear future. Modern technology is already capable of building fast reactors, but we do not have all problems solved on the fuel cycle side. Given this reality, there is now a pressing need to demonstrate a credible and acceptable way to safely deal with used nuclear fuel in order to clear a socially acceptable pathway for nuclear fission to be a major low-carbon energy source for this century.

The culmination of the Senator’s proposal – building the first standardised commercial fast reactors, which is still a step short of “full deployment” after all – would certainly “provide reliable, economic baseload electricity” for South Australia – as a potentially cost-free byproduct, no less. Yet the value of providing the full scale demonstration of a Generation IV fast reactor which runs on conventional used fuel reaches far further. Like potentially getting us on track to avert major climate disruption far-further.

All of which prompts the next big question: why isn’t another country doing this?

Why not the US? Well that’s relatively easy – the whole regulatory framework is still inflexibly built around conventional pressurised water reactors. Maybe this would be different now if the IFR programme had been saved from needless cancellation in the 90s. The NRC expects to see a customer committed to PRISM commissioning before it begins the certification process for the design.

Canada? A more flexible licencing regime by many accounts, and nuclear waste management money already put aside. But the conflict, if Canada were to pursue SFRs, is apparently between federal spent fuel management regulations and the provision of electricity supply, which is a province-level concern. Moreover, Canadian technology supports a somewhat competing approach in DUPIC.

The UK? Well, PRISM remains a contender for the job of dispositioning Sellafield stockpiles, and a final decision is expected this year after years of waiting. GE Hitachi originally offered to bankroll the reactors themselves. The UK might well be where it happens first, but it hasn’t happened yet.

France’s Superphénix 1200 MW fast reactor.

France? France had her own demonstration fast reactor, Superphénix. It suffered from years of technical issue-prone operation, and for this it is often dismissed as a costly failure. However, translation of articles from the time (1996), which cite various French nuclear experts who were involved, reveal that SuperPhénix was entering full revenue-positive operation just as environmental political pressure succeeded in shutting it down. Progress has been glacial ever since.

This doesn’t necessarily “leave it up to us”. But it does bring the opportunity into sharp focus. In an aggressive scenario, that lucrative recyclable fuel is being loaded into reactors freshly built by Dr Loewen’s team, along with numerous major local contracts, by early next decade. Essentially overnight, much greenhouse gas-emmitting infrastructure is displaced from SA’s grid. Carbon intensity and power prices are slashed.

Despite this technology representing the solution to the traditional concerns of nuclear risks and waste, established opposition has dug in its heels – truth be damned. It’ll “break the grid” they claim, or “it doesn’t exist yet”. What might have happened if Orville and Wilbur Wright had been forced out of the nascent aviation industry because their glider was first-of-a-kind, unproven technology? Commercial flight is now a multi trillion dollar industry and underpins the modern world. Fast reactor technology is dramatically more proven than the first planes were, and will provide an even more fundamental product.

What about SA wind and solar? We hear all the time how renewables will be disruptive – can we get any more disruption than what has been described above? It would also be good to get as dramatic about dropping carbon intensity. Yet renewables are part of this effort, not competitors. Indeed, recent analysis has looked into the integration of renewables and nuclear, together with flexible cogeneration such as desalination. Well, it so happens that South Australia has an idle desal plant. Together with the demonstrated load following capability of fast reactors, and NEM interconnection, a well balanced and low carbon grid seems – even if still a ways off – at least worth seriously thinking about.

 

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No, Dig Up

“If nuclear lobbyists want environmentalists to support nuclear power, they need to get off their backsides and do something about the all-too-obvious problems such as the inadequate safeguards system. Environmentalists have a long record of working on these problems and the lack of support from nuclear lobbyists has not gone unnoticed.”

So says the response to last month’s Open Letter to Environmentalists on Nuclear Energy, which was alluded to briefly in some coverage. Notably, many other outlets boldly elected to exclude such belligerent, opposing opinion, such as The Independent UK, The Morning Bulletin, The Australian, Bustle and ZMEScience, plus this deservedly proud piece from French Ekonomico. The full response was in fact an embellished email sent to the 75 signatories in an attempt to have them retract their stated support.

@JohnDPMorgan And none did…

— Barry Brook (@BraveNewClimate) December 27, 2014

These academics, experts and professionals are not “nuclear lobbyists” – which is a bit of lazy polemic when their credentials are what you want furthest from your readers’ minds. As the Open Letter addressed concerns around nuclear waste through specific support of ready-for-demonstration fast breeder reactor designs, the response instead focused primarily on proliferation safeguards. A quote is chosen from George Stanford which reads very much like a warning – however, he was entirely in favour of commercialising the IFR without delay.

If we want to be able to influence safe [sic] the spread of nuclear technology, we will rapidly do a commercial-scale demonstration of the superior IFR technology, including pyroprocessing of the fuel, and share the technology— with appropriate safeguards. …although thermal reactors consume more fuel than they produce, and thus are not called “breeders,” they inescapably create a lot of plutonium, as I said. And that poses serious concerns about nuclear proliferation. And proliferation concerns are even greater when fuel from thermal reactors is recycled, since the PUREX method is used. IFRs have neither of those drawbacks.

You are supposed to stay scared of the proliferation potential, and certainly, despite the desensitising saturation of films and video games with fictional nuclear annihilation, nobody would welcome more bombs in the world. But the dearth of context and conflation of technologies is intentional: commercial reactors are hardly ideal for making bombs, and alternative methods are no less straightforward. Expansion of nuclear generation in established countries cannot be expected to add to these concerns, nor would adoption of same in stable candidate nations. While groups who egregiously misrepresent the drawbacks of nuclear energy certainly spare no expense in protesting nuclear weapons, it’s complete rubbish to paint international safeguards as somehow crumbling at their foundations from any lack of effort on the part nuclear energy advocates. What are our modern examples? Iran, which has received constant yet superficial coverage for the last ten years, to the extent that President Rouhani himself is pretty sick of the sanctions and is challenging the remaining hardline element that still appears to hold WMD aspirations. As for North Korea… they are the international pariah and the butt of jokes which get made into movies. That’s what a nascent rogue state can look forward to if they can somehow cover the effort and risk of pursuing a nuclear weapons program.

Pictured: at least 6 nuclear power plants supplying emission-free electricity to millions. And a failed nation.

An anti-nuclear response to this letter is sadly to be expected, but is it futile to hope for something anchored in science and research, as was the original peer reviewed material, let alone to acknowledge climate change? “Climate” and “emissions” appear only in excerpts from the letter, while “carbon” is absent. Mentioning anything about climate change, let alone nuclear’s serious potential for addressing it, would dilute the fear of course.

“Nuclear power ranked third overall and was credited for reducing 2.2 billion tonnes of C02 annually.”

Here’s an alternative: instead of treating these distinguished professionals like dupes, or like they were negligent in their own research, try looking past the emotional investment and maybe finally ask, “What if..?” You know – like many normal, unsalaried environmentalists are no doubt doing now.

Time to stop digging.

Generation IV

This debut post is a concise summary of the modern approaches to realistic, efficient nuclear power that heed traditional safety concerns and cost effectiveness, which I wish to promote as the clean, modular sources of baseload electricity for the near future.

MSR

The molten salt reactor is basically a chamber containing high temperature, unpressurised liquid phase fluoride salts, with a moderation mechanism such as control rods, and inputs and outputs to access the generated heat. In the design built and tested in the 1960s at Oakridge National Laboratory, a mixture of fluorides of lithium, beryllium and zirconium was used as the coolant, containing uranium fluoride as fuel. It was tested for a total of 6000 hours (250 days) without incident.

The striking advantages of this approach to nuclear power would have been realised in the following phase of research, had funding been continued. The MSR fissioned U-235 (and then U-233) to generate heat, but a further layer of subtly different fluoride coolant was intended to “blanket” the main coolant chamber such that it was exposed to the neutrons from the reaction. This blanket would contain thorium fluoride as the fertile fuel.

Thorium exists naturally as a single, ubiquitous radioactive isotope. It is responsible for much of the harmless background radiation in soil, sand and rocks which nobody spends a second’s thought on. Thorium-232 would “breed” uranium-233 after capture of a neutron, and it is this form of uranium which would fission to provide further neutrons to sustain the chain reaction. Used in this way, molten salt reactors would rely on an abundant primary fuel that is currently considered a worthless by-product of rare earth mining, and which, in principle, could be concentrated from soil or rock from nearly anywhere. Moreover, the homogenous nature of the liquid fluoride fuel ensures essentially total conversion: every watt of thermal energy would be produced.

Other actinides, in suitable molten salt form, could also be used to fuel the MSR, hence this technology represents an avenue for permanent disposal of waste and weapons-grade material. In addition, intrinsic passive safety features promise “walk away safety”. For a start, the reactor fuel is already in a high temperature (>650C), molten state, so the concept of “nuclear meltdown” is entirely circumvented. The density of this liquid in the original experiment was observed to oscillate so as to accelerate and decelerate the chain reaction and “load follow” the energy demanded of the reactor. As for emergency shutdown, an outlet pipe at the base of the reactor is cooled by an electric fan which keeps a “plug” of salt frozen within. Failure of the system would cause this to melt and allow the molten salt to drain harmlessly into basement storage tanks. Finally, the near-atmospheric pressure of the reactor means no large, thick concrete containment is necessary.

The reaction heat is exchanged into a separate salt or steam loop to drive a turbine for electricity, but the high temperature is also ideal for chemical and industrial process heat, such as water desalination. Although this reactor concept is being promoted in the U.S. as LFTR (Liquid Fluoride Thorium Reactor), a major Chinese research centre has dedicated a group of about 300 workers to establishing the MSR technology based on the Oakridge results.

Flibe Energy

Transatomic Power

Terrestrial Energy

IFR

The integral fast reactor is envisaged as self-contained reactor, generator and fuel recycling plant. It is specifically based on liquid metal-cooled fast breeder reactor technology, as opposed to traditional water-cooled thermal reactors.The enriched uranium and other fuel derived from spent nuclear or weapons-grade material is fabricated, as oxides, into solid fuel along with sodium metal. At operating temperature the liquid sodium, as well as circulating and transferring the reaction heat, fills the voids left by fissioning material and acts to maintain steady neutron density.

These neutrons interact in the fast spectrum, with much the same energy as they had when they were released. This results in breeding of further Pu-239 from fertile U-238, and thus the eventual consumption of virtually all the nuclear fuel (in comparison, a traditional light water reactor will use less than 1% of the solid fuel material). The resulting spent fuel is recycled in a pyro-processing facility, powered by the reactor, where remaining useful isotopes are extracted and incorporated into new fuel, and actual waste is treated for long term storage.

The most promising IFR is known as PRISM (Power Reactor Innovative Small Module), the result of extensive testing of the liquid sodium-cooled reactor concept in the form of the successful Experimental Breeder Reactor II, which ran from 1965 to 1995. Actual scenarios were demonstrated where coolant flow was shut off at full power, resulting in natural expansion of the reactor liquid and shutdown due to low enough neutron density. Other passive safety features are provided by refuelling and generating mechanisms integrated into the reactor itself under the sodium coolant, which is securely sealed from interaction with oxygen or water. This also implies a modular design philosophy which will enable assembly line production reminiscent of passenger aircraft construction. PRISM is ready for assessment by various countries’ regulatory authorities; China is known to be constructing a similar reactor.

Similiar, modular concepts include:
The ARC-100
The Energy Multiplier Module

SMR

Small Modular Reactors are a broader class of modern reactors which generally offer an output under 3-500 MW, integrated coolant circulation, safety systems and power generation, and rapid assembly line production. Some approaches boast the need for infrequent refuelling. Strictly speaking Generation-III+ technology, among the many designs, the Westinghouse SMR is somewhat like a miniature model of the state-of-the-art AP1000 power plant, many of which are currently being erected in China. The increased economies of scale and standardisation of components which do not require prohibitively large production facilities promise an increased power output per unit area of footprint and per total fabrication costs.

Update December 14th: The SMR design to be prioritised through U.S. federal funding is the NuScale design, an incredibly portable reactor concept with a nominal electrical output of 45 MW. Read about it here.

Here is an animation of the construction of the first Babcock & Willcox mPower plant. The mPower will be rated at 180 MWe per module.