Interview with Professor Rodney Ewing – Department of Geological Science and Nuclear Engineering at the University of Michigan
On November 2, 2006, I chatted with Professor Rodney Ewing of the University of Michigan. Dr. Ewing has been studying methods for disposal of used nuclear materials for more than 25 years.
He made a recent speech to the Geological Society of America in which he framed the choice of proceeding with nuclear power as follows:
“Plutonium versus carbon—which would you rather have as your problem? I don’t have the answer, but the points I’m raising are ones I think people need to be considering.”
Prof. Ewing’s other main issue is that he thinks that the scale of nuclear power development necessary to make a significant contribution to alleviating greenhouse gas production is rather awe inspiring.
According to his calculations, there would need to be as many as 3,500 new nuclear power plants built between now and 2050. Though he acknowledges that nuclear power developments have a role to play, he is concerned about the monetary and intellectual resources that would be required for this huge expansion. Of course, the prospect of such a large number of new nuclear plants sounds pretty terrific to me!
This show is even longer than our normal show; Dr. Ewing provides some excellent and patient explanations for his points of view, while I think he might even have learned something from mine. I hope you enjoy the show.
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Rod,
Excellent show! One of your best yet! It was intriguing to hear the academic opinions of Professor Ewing.
One point I would make on the “economies of scale” discussion; the decisions to migrate to larger scales have been born of economic necessity, not of philosophy or choice. The responsibility is shared between the regulator, the regulated utilities, and the plant designers.
The regulator – because for years they chose to mandate increased staff sizes as fixes to design or performance shortfalls – for example, the STA position, appendix R safe shutdown rules, the station blackout rules, the maintenance rule, and even now the pending work-hours limitations. Every additional operating shift position adds 6 full-time-equivalents, and probably $750,000 per year in operating costs.
The designers – for designing overly complicated control rooms and safety trains. More controls require more operators and more technicians to maintain them. More pumps and valves mean more maintenance techs and more system engineers….
The regulated utilities – for bowing to the regulators too easily in the 80’s and 90’s because if the government mandated more staff they could pass the cost on to the rate payers.
In the end, the staff sizes required to operate this generation of nuclear plants is too large, and a small plant needs virtually the same staff as a 1200 MW unit. I’ve often made the analogy that PEOPLE are the real “fuel” of nuclear plants because the technology has become so labor intensive, and the cost of the actual fuel is miniscule compared to the cost of people.
There is light at the end of the tunnel (I hope). Utility executives are challenging the next-gen reactor vendors to design with smaller staffs as the model. That forces a different way of thinking right fro the start.
I know of one specific example of a senior utility executive telling a vendor to “go back to the drawing board” because they failed to take full advantage of technologies available to make control rooms easier to operate, smaller in size, and more efficient.
The deregulated electricity market will help too, as long as we can keep the NRC from continuing their habit of imposing staffing increases to solve performance problems. In addition, the deregulated environment has forced utilities adopt a much more fiscally responsible problem-solving mentality and we’re getting better solutions and better performance as a result.
It will be a pleasure to get together next week!
John
p.s. sound quality was excellent on the interview. You’ll have to tell me how you recorded it.
John:
Glad you liked the show. I’ll answer the easiest question first.
(If you do not care about the technical details of a podcast set up, skip the next couple of paragraphs.)
My set up for the interview included the following components – Skype (Mac version 1.5.0.80), WireTap Pro version (version 1.2.0) a Samson C10U microphone using Samson SoftPre driver software, all running on an old flat screen 17″ iMac (1 GHz PowerPC with 768 MB of main memory) running OS 10.4.8. I used GarageBand for a bit of post processing, mainly to split the voice tracks and adjust the sound levels between the two speakers. On the other end, I presume that Dr. Ewing was using a fairly standard telephone; I used Skype Out to call a POTS (plain old telephone system) number that he provided.
That is nearly the same set up I have been using for the weekly chats with Shane for about the last 2-3 months. Did you notice any significant difference in the sound quality for this interview compared to the regular shows? The only real difference is that Shane also uses Skype so we talk completely via VOIP.
(Here ends the geeky podcast information. Now back to the atomic question at hand.)
With regard to your comments about the economy of scale being driven by staff sizes and control rooms – I would have to challenge the cause and effect. I will definitely not challenge the identified culprits of the designers, the regulators and the regulated utilities.
The reason that I challenge the cause and effect is that plant designers and builders had increased the offered plant sizes to 1000+ MWe by the mid 1960s from 60 MWe at Shippingport in the mid 1950s. That design choice occurred well before the NRC was ever split off from the Atomic Energy Commission. If you consider the S1W (Nautilus prototype) as the ancestor of all light water reactors, the rate of scale increase is even larger; that plant produced less than 15 MW of useful power.
Utilities and their traditional suppliers (GE, Westinghouse, Babcock and Wilcox, Combustion Engineering) had become interested in scale economies long before Shippingport; the size of coal fired steam plants had already gone through a rapid scale up evolution, resulting in decreasing electrical power costs throughout the 1940s and 1950s.
It made sense to decision makers to apply the same techniques to atomic energy. Here is a quote from “Light Water: How the Nuclear Dream Dissolved” by Irvin C. Bupp and Jean-Claude Derian, published by Basic Books in 1978 p. 47 –
There is a lot more information about the decisions and events that led to the “Great Bandwagon Market” in nuclear power plants and its collapse in that book. Note the publication date – one year before TMI, which means that the writing had probably been done about a year before that.
I liked your interview on Episode 37 with Dr. Ewing. However, I have an observation on one of his comments. One of his arguments was that the nuclear industry did not invest much money into nuclear fuels or reprocessing, whereas the fossil fuel industry does. I thought that was pretty clear myself, as the fuel costs for a reactor are a tiny fraction of the operating cost, fuel is readilly available and abundant, and you only need to refuel the reactor every so many years. When you do refuel, we are talking about a very small amount of matter. Moreover, the nuclear industry can buy ahead and build a nice, comfortable stock pile in advance of their use, and can store that stockpile indefinitely. You could easily buy 50+ years worth of fuel in advance and store it on site just in case some weird event makes Uranium hard to get.
The oil industry, however, must continuously search for new supplies simply because it is relatively scarce, finite in supply, and tough to stockpile meaningful quantities (days of supply) simply because of the sheer volumes of throughput. As you talked about in one of your earlier shows, even small perturbations in supply cause calamities in the prices of oil because they can’t buffer it. In short, fuel availability is not a constraint in the nuclear industry, but it IS the industry when it comes to fossil fuels.
So why would the nuclear industry invest in something when it really has no financial incentive or supply constraint involved? Only when you make it more attractive as a method of disposing of the “waste” by using spent nuclear fuel, or if Uranium gets expensive enough to make it fiscally feasible will they do it on their own.
PowerPointSamurai:
Glad you liked the show. I tend to agree with your analysis, but I offer a couple of reasons why the nuclear industry should pay a bit more attention to research and development in general and for advanced nuclear fuels in particular.
1. Though the fuel cost for nuclear power plants is a relatively small portion of the operating cost, it is not exactly a small number. According to recent industry figures, the fuel cost averages about 0.45 cents per kilowatt hour. For a 1000 MWe power plant operating at an industry average of 90% capacity factor, that add up to about $35.5 million per year. When you multiply that by 100 reactors, you get a rather substantial $3.5 Billion per year for nuclear fuel just in the US.
2. There is a lot of room left on the typical s-curve of technology development for nuclear fuels. Right now we use about 3-5% of the initial potential energy, there are a couple of doublings available before the top asymptote is reached.
3. Nuclear waste is used by anti-nuclear pressure groups as a means of constipating the industry. It would sure be nice if the industry could look people in the eye and say that we are developing new ways to use that material.
Oh, I agree with you, Rod, especially on the issue of “waste” disposal. I just have the inkling that nuclear fuel costs and availability aren’t driving the nuclear industry to invest heavily in it or developing new technology there. The “waste” disposal issue could be the catalyst that makes this happen though. Now that Harry Reid has the Senate, things don’t look so great for the Yucca Mountain project. I suspect Mr. Reid will try to throw up every stumbling block he can to new nuclear development, and I suspect every one of those blocks will begin with the “waste” issue. The nuclear industry could assure its growth, it’s fuel sources, and put this “waste” issue to bed by simply telling Mr. Reid, Greenpeace, and all the naysayers “No thank you, we don’t HAVE any waste for you to worry your pretty little heads about.” and re-use the stuff–and all the fission products. Aside from the ones you talked to Dr. Ewing about, the one I am most interested in is Xenon. Since Mr. Reid and some of our elected officials seem so intent on re-purposing the disposal funds the industry has set aside, it seems to me that they should be able to invest that money into Dr. Ewing’s solution to the “waste” problem purifying spent nuclear fuel into new fuel and other valuable products. Sounds like a “win-win” to me.
Hi Rod,
Just listened to the show…a few comments.
Dr. Ewing pointed out that uranium has two oxidation states, +4 and +6. +4 is very stable, +6 is more volatile. In oxide form, +4 is UO2, and in fluoride form +4 is UF4. A fluoride reactor exploits the fact that uranium has two oxidation states (and thorium does not) to achieve extraordinarily simple reprocessing.
The standard form of the uranium in the reactor is stable UF4. To remove uranium, oxidize it (through fluorination) to UF6, which is gaseous. To remove bred uranium from thorium, same thing. Uranium will oxidize (to a volatile, gaseous compound) and thorium will not.
Extremely simple reprocessing and unlimited burnup possible in a liquid-fluoride thorium reactor, along with the fact that the cycle doesn’t produce transuranic isotopes, solve other issues and concerns that Dr. Ewing brought up about plutonium, waste storage, and deploying the large numbers of reactors we need to displace coal.