1. Sitting in an airport in Guam and having been in the islands of Micronesia lately which are totally dependent on shipping, I am interested in these questions. Frankly, I am interested that there was NO mention of using Atomic power for these ships which would reduce their emissions to zero. More and more I see applications for small scale power plants. I noticed that the research reactor at Ohio State was only 500 KW. If we can make research reactors this size why can’t we make power reactors this size? Is it cost? Is it safety? A half megawatt generator would be great for many backup situations – like hospitals or office buildings.
    In the case of ships, your design using pebble bed reactors is an interesting adaptation that is looking more and more viable with the production of the pebbles in South Africa. I am wondering if your design would work with super critical CO2 which would make it even smaller. (but not as “off the shelf”)

  2. Dave:
    There is no reason why a closed cycle gas turbine would NOT work with super critical CO2, but that is not the path that I would recommend for the first units. Though we know a lot about how to make high temperature fuel, there is very little actual experience in how it will perform over the long haul in challenging situations. I prefer to limit technical risks and take incremental steps.
    Besides, compared to a steam plant or a diesel engine, an atmospheric pressure gas turbine is already quite a bit more compact. When you add in the weight and volume required to store a couple of weeks worth of fuel for full power operation – as is required for an ocean going commercial vessel, the benefits of atomic propulsion in terms of weight and space become even more apparent.
    Aside – stay tuned for more coverage of this particular market. I have been doing quite a bit of research, especially recently. That renewed interest was sparked when I found out that the CEO of China Ocean Shipping Group had approached international maritime organizations to let them know that his company was leading an effort to investigate the use of nuclear ship propulsion.

  3. Dave,
    CO2 as a coolant for a graphite reactor has some severe temperature limitations. CO2 is reactive with graphite to produce carbon monoxide.
    Helium and nitrogen do not react with graphite and are thus the preferred coolants for graphite.

  4. Rod,
    Rolls Royce, who makes the nuclear reactors for the British Navy, said about a year ago that they were pursuing the commercial maritime application. Don’t know what has happened since the announcement.

  5. Rod I see you are still confused between pollution and emissions.
    If the air is clean, there is no pollution. If you live some place with a few million cars stuck on the belt way breathing each other fumes replacing coal plants and oil burning ships is not going to fix your problems.
    If your problem is high heating cost because you heat with NG, new nukes will help. Really, really big ones; not those sissy toys the navy has.

  6. @ Kit P
    Kit – frankly I am confused by your comment. While I don’t consider CO2 to be pollution – I like to breathe – there is no question that burning bunker oil in cargo ships produces pollution – not just CO2 emissions. Replacing the power plants of ships with a nuclear source would reduce pollution. So I am not sure your comment even touches the subject of the blog. Sure, if the air is clean there is no pollution. At least not in the air. The slide show was arguing that the pollution was being transferred to the ocean through increased rain. I am not sure how they know this and I am not as confident these days in simply accepting the statement. However, if you want to argue that the pollution in the ocean transferred from the ships is of no consequence – have at it. You might be able to make a point with some clear science behind it – or you might not. But it would need to be more than an opinion.
    Your point about cars totally shifts the focus and does not address the issue raised.
    It seems to me that case for replacing the power plants of ships with small nuclear is cogent.
    About heating homes and businesses. Actually, if we are using Atomic energy to produce electricity thus driving down the cost of natural gas, it makes a great deal of sense to use natural gas – methane to heat with. It is a high efficiency use of a distributed heat source. Building large power plants to generate electric that is then converted back to heat produces a large number of system losses.
    Finally, why the constant deprecation of small nuclear power? In the context of powering a ship – it is very fitting to look at sizes that the Navy has demonstrated to work well. In the context of needing to add incremental capacity to a grid, small nuclear is about the same size as the current NG turbines that utilities have been installing for the past few years.

  7. @ Bill
    That is a good point. Reactors that use a graphite moderator would have a chemical reaction with CO2 if it was passing over the graphite – which in a pebble bed reactor it very much would.
    @ Rod
    your comment about size calls to mind a recent discovery channel / or national geographic “mega build” show that was focused on the new cargo ships. The engine for that ship was the size of a warehouse and they had to lift the ware house off the engine in order to be able to lift the engine into the ship. It was huge!
    What space would a similar capacity nuclear power plant take up? I know I have read this somewhere on your blogs but perhaps you can remind us here.

  8. Rod, the slide show worked great. As I recently learned the emissions from ships are equal to a very large number of cars, putting nuclear power in these vessels seems like the next big low hanging fruit especially when the economic benefits are considered.
    A pebble bed Adams Engine seems like the perfect reactor for these types of applications.

  9. The Adams Engine could even save on first cost given the complexity of large-scale internal combustion engines, especially those needing emissions controls, as well as definitely massively save on operation cost, though I would expect a prismatic design (as opposed to a pebble-bed design) for a small reactor would be the simplest and most space-efficient way to arrange the core.
    (Of course, you should expect “some” resistance from the oil companies, the oil “amen corner”, and the oil sheikdoms. They like disposing of their low-grade 2% sulfur bunker oil on ships.)

  10. David, I am sorry you are confused but evaluating environment impact is a complex. I am better at not being confused myself than I am teaching other not to be confused in a few sentences.
    ?Finally, why the constant deprecation of small nuclear power??
    My problem is not with small reactors but arm waving from supporters. Just because you find something interesting does not mean that it is a good solution. Fit the solution to the problem.

  11. @ Kit P.
    Well, I suggest you improve in these areas if you want to persuade people in a conversation. Perhaps you are right. But in a conversation like this I have no idea what your basis for your comment is if you don’t explain.
    Also, when I say I am confused by your comment, I am asking you to explain why you are transferring the conversation from unregulated pollution pouring out the stacks of large ships to the pollution that is highly regulated coming out of cars and land transportation.
    In the case of ships – replacing huge diesel engines with compact nuclear reactors which do not pollute or emit seems like a good substitution. If you have concerns about that why not express them rather than jump to cars? Let’s hear your opinion about that.
    In your opinion is it a good thing to replace the power plants of ships with nuclear power?

  12. Dave you are still confused between pollution and emissions.
    I am not trying to to persuade you about anything. I do not need to build a consensus.
    Dave, I would think it would be good to solve environmental problems based on science and not emotion.

  13. Then why are you here?
    You want to accomplish what with your comments?
    Why do you refuse to answer the questions I asked?
    You say I am confused about emissions and pollution but you don’t clarify anything. (I am not confused about that point at all. Pollution is the subset of emmissions that harm the environment while emmissions are any output from a combustion which may or may not harm the surrounding environment).
    You did not respond to my comment or question. You ignored my pointed comment and question. You have not provided any science.
    I can only conclude, (unless you really want to do more than poke fun) – that your concern here is just to irritate with an attitude of superior knowledge but no display of the same.
    Hand waving? Frankly, for myself, I am interested in solving power problems in a pragmatic way that allows for cheap and accessible power for most if not all of the world’s population. Having lived and visited many countries in Asia and the Pacific where the cost of power is enormous and a huge block to economic development I am very interested in the development of power resources that are long lasting, portable or compact, and of high energy density as well as being cost competitive. Small nuclear comes very close in this regard. In places where Hydro is fully utilized and there are few options for other kinds of power a small nuclear power plant could be a large boon for these isolated communities.
    For ships, the subject of this thread, I think the wide use of nuclear is a great application with few drawbacks and many benefits to commerce as a whole (except for countries whose main export is oil – like Mexico).
    On the other hand, the “hand waving” about nuclear power is justified on the scientific case that it is the best solution to electric power production and could be a wonderful solution to other types of heat needs including chemical production. So both the present applications – large power generation and ship propulsion are great. At the same time it is helpful to continue the development of smaller sizes to provide for needs that a large power plant cannot address.
    You seem to hand wave about large nuclear power plants dismissing small nuclear plants with the pejorative “sissy.”
    I see an opportunity.

  14. Yes David I am dismissing small nuclear reactors because they are small. It is not rocket science. For some reason folks who make up stuff based on junk science feel others are obligated to use real science to debunk stuff they make up. I have no problems with marketing brochures as long as you understand that it is just a piece of paper.

  15. Well, at least now we understand your perspective. Small = junk science
    Sure explains why your comments are sharp but does not explain why you are hanging around us junk scientists who are convinced that Mpower and LFTR Navy reactors are now or have been real working power generators.
    A few years ago I got into this topic after reading MIT’s proposal for a modular pebble bed reactor. It was the first time I saw that reactors could be both modular, factory built and potentially smaller and more distributed than the current models. The inherent safety of the design was very attractive since it answered many of the objections to nuclear power.
    This followed two or three years of looking at “alternate energy” sources, wind, wave, solar motivated by the high cost of electric in the country I live in and by my desire to help some of the poor communities I have interaction with. I came away from that research with a deep respect for the energy density of gasoline as a fuel.
    While I do not agree that we are in a “crisis” over “global warming” I am persuaded that energy costs are too high to sustain growth. Being able to build a distributed grid, being able to place power in remote areas that are difficult to serve with typical transportation and pipping is a good thing. It will strengthen human development. So I am very interested in the development of factory built small / modular nuclear power plants.

  16. Kit – I am “intrigued” by your perspective. Though the word “small” is always relative, it is kind of amusing to think that there is a field where a machine big enough to supply all of the power needs of 10,000 (Toshiba 4S) to 125,000 people (mPower) can be considered too small to matter, especially when the design is specifically aimed at being able to be reproduced in a moderate period of time in a factory setting.
    (Based on common rules of thumb, 1 MWe is enough for roughly 1,000 people, but even if the people really like to do things that require a lot of energy and 1 MW can only supply the needs of 200 to 500 people it still seems like those are reasonably sized machine to me. My study of the combustion power market tells me that there are plenty of machines in that range burning diesel fuel, bunker fuel, natural gas, and other distillates in that power range.)
    As Dave, who lives in a nation full of islands without good grid connections or road transport can attest, electrical power that does not need continuous fuel supply infrastructure is a very useful thing to have. It is so useful that people pay as much as 10 times as much per unit for that power as they do in places where the grid is well established and able to burn cheap coal (cheap, that is, for systems where part of the cost can be dumped on others by avoiding any responsibility for the waste.)

  17. David Phillips
    It is pointless to argue with a person like Kit P. He must be some kind of super engineer that knows it all and he argue by being arrogant, or he is just a kid trying to be smart.
    As far as most of us engineers are concerned, there is no difference between emissions and pollution. When you emit something into the environment you pollute no matter what is it you emit.
    Nuclear power minimize those emissions. Saying that small reactors are sissy is really an arrogant statement.
    I wish there was a small sissy reactor around I could employ in our biodiesel and synthetic diesel fuel production. If there was such a reactor we would produce 30% more usable fuel and we would not emit anything into the atmosphere. Does Kit P actually know there is pollution created in alternative fuel production just as pollution is created in oil refining? Those small sissy reactors would be very helpful to eliminate that pollution while helping us to extend feedstock supply.
    Simply speaking, there is a critical need for those small sissy reactors and it is only the ridiculous politics stopping us from using those little sissies.

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