Thank you for your comments; they are greatly appreciated. Yet, I think there have been some misunderstandings regarding Jack Spencer’s free-market approach to managing used nuclear fuel. One, I wouldn’t necessarily call the private entity that manages Yucca Mountain a “monopoly private entity.” In fact, the private entity would be set up to be just the opposite, and as he writes, it could take a number of forms. We see it as being independent but fully representative of the nuclear industry so that “no operator receives preferential treatment and that the private entity operates as a service to all nuclear operators.”
As for Yucca Mountain, Spencer’s central point is that we don’t really know what’s in store for nuclear waste once it’s in the hands of the private sector because they will do what is most economically rational, which could change at any given time. It could be interim storage at one point, reprocessing at another and geologic storage at yet another – or some combination. In all likelihood, this could create a market for geologic storage if private entities see it profitable. We agree that if plant operators do not want their waste, they could pay someone to take it, but whether that waste lands in a geologic repository or a reprocessing plant will be determined by market signals.
Nick:
I guess I am a bit of a skeptic about an entity that controls access to a single asset that is "fully representative of the nuclear industry".
What about those innovators that are not yet a part of the industry that just might have better ideas and want to challenge the dominance of the established industry?
My experience is that business managers are indoctrinated during MBA courses to lean towards efforts to protect their market share. The professors call it "raising the barriers to entry."
Believe it or not, there is no single standard of economic rationality. Some thinkers only consider immediate or near term returns, others are willing to patiently build technology and understanding knowing that the payoff from long term visions is often far more rewarding on many levels.
I think that used fuel materials should be considered nothing really special compared to all other industrial materials. There is no reason to centralize the management, whether the organization in charge is "private" or governmental.
Discussions of reprocessing often forget the "other waste problem."
PUREX produces large volumes of liquid waste, stuff that's not as hot as VHHW, but that must be isolated from the environment none the same.
Large and expensive cleanups are going on at Hanford, West Valley, and soon at Sellafield. Who knows what kind of mess the Russians and the French are dealing with.
Rokkasho might be pointing the way to the future with a LLW evaporator and integrated vitrification plant, but capital costs have been an order of magnitude larger than European reprocessing plants. It's functioning in a Japanese culture which is capable of both incredible quality and destructive groupthink. It will take at least a decade of experience at Rokkasho to start to evaluate environmental and worker safety.
At least the fission products and transuranics in spent fuel rods are trapped in a ceramic matrix and not going anywhere. The current situation where they're cooling off for a few decades at the plants where they are generated are letting the fission products decay, meaning they'll be easier to handle when it comes time to ship them to Yucca Mountain, send them up to Canada for physical reprocessing into CANDU fuel, or reprocess them to make plutonium feedstock for a future fast breeder (yikes!) or to start a thermal breeder economy based on thorium.
A sustainable breeder economy, however, is going to have to recycle fuel more quickly, makign reprocessing plants considerably dirtier. In the meantime, the "twice-through" cycle of MOX fabrication in Europe and Japan seems dangerous and uneconomic.
Paul, I don't know if you've seen my writings on the very simple reprocessing possible with thorium and liquid-fluoride fuel, but I encourage you to take a look at it if you get a chance.
I see two troubles with the molten salt reactor: (1) A lot more activation around the primary loop, and (2) you'll be reprocessing fission products that haven't had time to decay. You'd to be thousands of times more rigorous about leaks than a PUREX plant would, even if you've got less inventory.
You've got choices in thorium breeders: Shippingport demonstrated 1.03% breeding ratio in a converted LWR. Something derived from CANDU and the PMBR are also possible, and I think the PBMR is particularly promising.
The physical barriers in the PBMR fuel element reduce radiation leakage in normal and accident scenarios by orders of magnitude. It's hydroneutronically stable but has excellent neutron economy: mechanical control of the fuel means that core composition can be adjusted spatiotemporally and that fertile and fissile elements could be separated mechanically for reprocessing. It could do some of the tricks that the salt reactor reactor does, like let pebbles sit in a noncritical assembly so neutron poisons can decay. It can certainly breed better than Shippingport.
PBMRs can currently run on cheap uranium: we can wait a few decades to decay -- we can even bury it then if we want to. When economics are favorable, we could create U233 from high enriched U235 or run our stock of LWR and PBMR fuel through PUREX to bootstrap the thorium economy.
Paul:
Thank you for your insightful commentary. No real disagreement here except to remind people that the PUREX process that you mention was specifically designed to extract weapons grade Pu during a war. It was the quick and dirty means that worked to achieve the given goal.
I do not advocate its use and never have. When I talk about recycling, I am talking about processes that keep all fissionable materials in the fuel cycle.
Oh yeah - one other quibble - why would a "sustainable breeder economy" need to do the recycling so quickly? What is wrong with a long term plan that allows a couple of decades of cooling down between fuel uses?
Great comments, by the way, about PBR's.
Well, PUREX (by which I mean anything based on nitrate chemistry & solvent extraction, so that includes THOREX and UREX+) is the devil we know. It's a second-generation process developed for the nuclear weapons industry, not the really quick and dirty process used to develop the first few weapons.
For all of it's faults, we've got decades of operating experience with PUREX, just as we do with the LWR. We know what can go wrong and we know how they interact with our countermeasures. Although the 2005 spill at Sellafield reflects an appalingly poor level of control over the process, it demonstrated that secondary confinment worked, just at TMI demonstrated that LWR confinement works. When reliability matters, there's a lot to say for incremental improvements on an existing process.
Any new kind of chemical reprocessing system is going to require a similar period of time and development before we really trust it. The hydrofluor process looked promising, but they were unable to scale for commercial use at the Morris plant. Pyrometallurgy or any other process is going to require decades of development before it's going to be operating at the scale of Rokkasho or THORP. (In terms of total amount of material processed globally, not necessarily in one place)
I've been thinking about the accidents in Japan in the last 15 years or so and the common denominator is that Japan is working on experimental reactors more than any other country. (Counts for Tokai, which was fabricating fuel for experimental reactors with a nitrate-based process.) It's hard to sell research programs to the public that generate more danger than the much larger commercial operations.
I think that's the big selling point of the PBMR: it's profoundly conservative in terms of safety, but has big benefits in economics and fuel flexibility. It certainly doesn't forclose reprocessing, but it discourages the Euro-Japanese MOX cycle since front ends don't currently exist for the fuel.
As for cycle time, it's hard to say. Thorium breeders are never going to have a high breeding ratio, so material processing would need to be quick to have a fast doubling time. The stuff I'm reading lately, however, says that you can build up a U233 stock fast with a relatively small make-up charge of U235, Pu or even neutrons from an accelerator.
What do you do with the 129I?
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