Floating off-shore nuclear power plant

MIT researchers are working on a modern version of floating nuclear power plants using concepts derived from the off-shore oil and gas industry. The facilities would be built in a shipyard and towed to their destination.

The concept does not seem to be specific to any particular reactor design, but is more of a siting concept with some features worth consideration and discussion.

The concept of floating nuclear power plants is not new. Neither is the concept of off-shore power plants. That’s okay, nearly every human innovation is a combination of pre-existing products, services and ideas.

I’m not entirely sold on the safety advantages of such a concept because I remain firmly convinced that our current land-based nuclear plants are adequately safe. However, I can readily see several advantages from a cost and flexibility perspective.

This is a concept worth further investigation. It is certainly something that is generating substantial interest in the media, but that might be more of a tribute to the efforts of the capable public relations group at MIT.

The Atlantic (April 17, 2014) Could a Floating Nuclear Power Plant Prevent Another Fukushima?

Engadget (April 16, 2014) MIT designs a floating, tsunami-proof nuclear plant

Discovery (April 18, 2014) Floating Nuclear Plant Would Ride Out Tsunamis

Business Standard (April 17, 2014) Floating nuclear plants may withstand tsunamis

The Verge (April 16, 2014) Floating nuclear power plants could avoid disasters like Fukushima

About Rod Adams

50 Responses to “Floating off-shore nuclear power plant”

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  1. Mitch says:

    No matter how well it works I think the concept just makes it even harder for land plants to get built because it hints to the clueless public that nuclear plants are so unsafe and super-delicate to any shiver that it’s best to shove ‘em all off shore!

    • Patrick McGuinness says:

      This is similar to prior designs that had a submarine version of a nuclear plant. On one level, quite innovative, but on other levels, it feels more like going in the wrong direction.

      Here are the problems with the concept:
      1) This is not a safer design because the risks of PWR are operational and minimal. Now that AP1000 has passive safety via gravity feed pools, and *any* PWR today can simply build a water tower for the same gravity-fed water availability, there are less drastic ways to get ‘water availability’ than offshore siting. the flipside are the risks you are adding via offshore siting. Who want to conduct operational management of an offshore nuclear rig during a hurricane? If it gets unmoored/demolished and heads to shore and/or releases materials in the sea?

      2) PR-wise, it does mislead people into thinking there is some issue with land-based nuclear plants, and so feeds mis-perceptions. Risks that involve the use of the seawater invariably involve heating up the seawater at least and radiation release at worse (eg like the ‘it gets unmoored’ scenario). From a PR perspective, this is Exxon Valdez or BP oil spill type of event. So we avoid 6-sigma prob of another Fukushima but still will have an accident that would be just as big PR wise.

      3) Cost – the interesting thing here is the ‘build it and move it’. Well, this is the wrong design for that. The *right* design is to get away from PWRs and go to a compact pool-type reactor that is factory-buildable and road/rail transportable.

      I have come to the conclusion that the future will be flouride-salt-cooled reactors not PWRs. the fundamental safety issue of PWRs is that active controls of the pressurized system is needed, so even if events are rare, they are *possible* (and as Fukushima showed, the 6-sigma events *will* happen sooner or later). Flouride-salt is a great coolant, like lead has a wide liquid thermal region – up to 1400C well above operating temps. Work by Forsberg, Petersen (UCB), and ORNL on FHRs have shown practical efficient designs. I did further analysis on the SmAHTR design, a small, rail-transportable reactor. It is only 100MW, as designed, but I analyzed how you could boost power density and with similar size with external heat exchangers, and you could have a 600-800MWe reactor that is flouride-salt-cooled as be rail-transportable. Cost would be 1/2X a PWR cost, perhaps even less as you get many economies of scale from the ‘factory-build’ model for medium-sized reactors. Another bonus, these FHR reactors are orders of magnitude safer in terms of thermal margins than PWR.

      In summary, sticking with PWRs is not the path to cost reduction, we should be looking at compact designs based on better coolants, and innovative siting ideas don’t fix/improve the PR or safety issues with PWRs in a meaningful way. JMHO.

  2. George Carty says:

    Wouldn’t it be a good idea to build nuclear reactors on a ship in international waters, outside the jurisdiction of any Big Oil-owned politicians?

  3. Benjamin Haas says:

    Unless this idea is marketed for its mobility and not for safety, it could increase big nuclear reactors’ flexibility and that’s a good thing. Otherwise, the major problem with these “keep it away from society” ideas is that it shoots all other forms of nuclear power in the foot by affirming public fears. What happens when the spent fuel carrying vessel comes along side and carries all of that radioactivity to shore? Again, the underlying problem is ignored.

    Arguing that nuclear reactors should be kept away from populaces also says that spent fuel storage, reactors that must be on land, nuclear-powered ships, and radioisotope generators are not acceptably safe. Some engineers have honestly considered having nuclear-powered ships detach their reactors from the hull when entering port, like a tugboat and barge, to avoid having a nuclear reactor in a populated area. Their logic is that nuclear ships in port will never be accepted by the public or insurance pools. There is a reason ships do not detach themselves in this way: cost and complexity, as well as having a second ship handle the cargo. These ideas also ignore that large ships can be towed more than 50 miles in a day and only spend a fraction of their time in port.

    Perhaps the safety of floating power plants could be argued for regions with severe earthquake and tsunami risks, where having it offshore protects the investment from damage, but even Japan only had 1 power station of 50(?) meltdown due to a 100 year earthquake.

    • Rod Adams says:

      @Benjamin Haas

      My interest in the concept has more to do with its manufacturability and its potential for relocation to a more lucrative power market if the original customers reduce their consumption.

      • Benjamin Haas says:

        @Rod

        I agree that that is a big selling point for the idea. I hope that’s how it ultimately gets described in the media.

        • Rod Adams says:

          That is Atomic Insights’s self-assigned task – influencing the way that the media covers this kind of development. My hope is to convince more of the great innovators who are interested in nuclear energy to start focusing their marketing messages on topics like cost reductions, construction schedule improvements, operational streamlining, and market adaptability.

          • Andy says:

            We need some nice sounding environmental activist organization, something like “Union of Environmentalist Scientists.” Then you can start lining up interviews and you can be treated as an authority by virtue of the fact that you represent an NGO, just as Amory Lovins and various anti-nuclear crackpots already are.

            It doesn’t really mean you have any more of a clue what you are talking about, but moving up from the status of a blog to the representative of an NGO somehow automatically establishes one as an authority in the eyes of much of the media. Doubly so if the NGO’s name really says nothing at all about it’s actual goal… (Lovin’s Rocky Mountain Institute ought to be called the Natural Gas promotional institute).

      • Rick Armknecht says:

        Rod,
        Another advantage to the ability to relocate: it keeps the politicians on a short leash.
        Suppose that these were built for Hawaii and they provided electricity at half the current price of electricity (no pun intended) — and that they were very profitable. Next, suppose that Hawaiian politicians saw the profitable plants as a source on income for the government and wanted to slap a big property tax on the plants. If the plants could just move to Singapore, then that changes the playing field.

        • Jeff Walther says:

          It would be pretty cool if Vermont Yankee could just sail away and re-base itself off the Texas coast….

        • Rod Adams says:

          @Rick Armknecht

          You’ve got it. There are also places in the world where people have been known to refuse to pay their bills. Once again, if a power plant operator can simply drag his electricity production factory somewhere else, it helps to ensure better behavior.

      • kaya says:

        You could build a small ……pond….by a river. Take this ship there. Drian your pond so its now land again.

        You have built a land reactor on land in one week delivered in one piece and youcan take it away in just one week after its 50 years of service.

  4. John T Tucker says:

    I was really big on these after fuku for what I thought were safety reasons but now I think, that wile good for emergency power somewhere the existing nuclear fleet is, in reality, extremely safe and SMRs could fulfill much of the emergency stuff.

    At any rate when not used in emergency situations these could be happily sitting somewhere offsetting coal and gas consumption so I think its still a good idea.

  5. James Greenidge says:

    I have to concur with Benjamin Haas that this notion, while plausible and financially attractive, seems to me a public nuclear perception boomerang that can’t wait to happen. Yes, I can see it applied to some specialized situations, but the worst thing to do for the image of reactors and confidence in their safety is to strut this idea out as a “alternate” siteing method to an unwashed and wary public (and eager to pounce greens) who’ll only and solely perceive it as a desperate ploy by the nuclear industry in addressing a “insoluble” safety issue by resorting to shipping nuclear reactors out to sea. I give my hat to the ingeniousness of the concept, but on a sheer struggling public perception and image issue this is not good for assuaging fears and gaining public confidence in nuclear power and SMRs safety on land and deep in-country. Thorium and Fusion folks take heed, you’d be swept up into the same boat.

    James Greenidge
    Queens NY

    • Engineer-Poet says:

      The issue of sea-level rise IS insoluble, at least by the nuclear industry itself.  Placing plants where they can simply lengthen their anchor chains a little bit and carry on would address that issue going forward.

      The difficulty I can see is designing a floating structure that will be seaworthy for 40, 60 or 80 years.

      • kaya says:

        USS Enterprise the nuclear carrier lasted 50 years and had 8 small reactors and that mobed around a lot and did many more things. Surely for a mostly stationary boat 100 years wouldn’t be out of the question if the war machine can last 50 years

        • Engineer-Poet says:

          The Enterprise went to drydock for repairs at least once.  Having to take your nuclear plant off-station to keep it from sinking is a complication that land-based plants don’t have.

          Perhaps the distance from populations and the guaranteed availability of cooling is enough to offset that.  Hey, let Bill Gates build a few and see how well they sell.

    • kaya says:

      If they could be built cheap enough governments would accept them regardless of a few unemployed loons waving placards

      Get them to $4/watt or less and many a nation would order them because

      1. cheap
      2. You can pay on delivery rather than the unknown time and cost and years of ignorant protest of a conventional.
      3 decommissioning is known and quick (send back to manufacturer)

      the most important is #2
      if you could buy ready built ships and pay on delivery and they worked and came with say a 15 year guarantee then finance would be cheaper loans than buying a house. With 3% ‘mortgages’ for these ships they woild be very cheap.

      Imagine a 250MW ship costing $1B
      The depreciation and interest cost over a 25 year loan would be less than $5 million a month.

      Each MWhe produced would thus have a capital and interest cost of $28

      Add staff and fuel and you are prpbably not much above $35. An extremely cheap price considering in europe wholesale prices are $70-80

      also the second half of its years when it is fully depreciated and paid off the $35 dollar cost per mwh would reduce to closer to $10

      The world could absorb easily 2 of these ships per week. Giving a huge $100 billoon a year export market for any nation which could do it plus about 2 million jobs building the things.

      only a few nations on earth could do it though. South korea. China. And the USA…maybe also Japan.

  6. Eino says:

    Well – First i thought that the rectifier – inverter stations and the big DC lines to get the power to shore would be a big hassle.

    Then – I thought some more. Today’s industrialists could build a whole factory out there in the ocean. This factory probably would not be under the auspices of any modern country if in International waters. Golly! These guys would have cheap energy from their nuke, access to materials by sea and I’ll bet near slave labor to boot. If they were too close to some government that gave them a hassle, they could just float the thing away.

    They would have access to the US and / or European markets. Maybe they would be regulated by the Liberian Nuclear Commission or some such organization.

    It may be a money maker.

  7. NNadir says:

    I made an argument elsewhere that floating nuclear power ships may be able to collect carbon – possibly for use as fuels for mobile systems such as tractors, trucks and well, cars – better than land based systems can do, via the agency of biofuels.

    The argument is buried deep in this somewhat tongue in cheek (in my own mind anyway) discussion of biofuel chemistry:

    http://theenergycollective.com/nnadir/361711/better-chemistry-better-biofuels-glycerol-glut-solketal-and-other-floating-ideas.

    Actually floating chemical plants using nuclear heat for processing is an idea I’ve thought extensively about, and written rather long notes to myself about. These types of systems would necessarily run off a vastly improved version of the old Soviet era lead cooled seaborne reactors.

    (Modern materials science has made the lead cooled concept well worth revisiting.)

    • Rick Armknecht says:

      “These types of systems would necessarily run off a vastly improved version of the old Soviet era lead cooled seaborne reactors.”
      Why “necessarily”? I can see why you would have a big problem with sodium cooling (water, water, everywhere . . .) and if the “floating” power plant is also submerged, then air cooling is out of the question. But why is water cooling out of the question? For that matter, why not molten salt?
      Note that I’m not “down” on lead cooling — it has lots of benefits and, yes, “the lead cooled concept [is] well worth revisiting”

      • NNadir says:

        I wouldn’t say “out of the question,” for some applications, but my biofuel post to which I referred would require either supercritical water gasification or hydrothermal depolymerization at the minimum.

        In general, I’m hardly a “biofuel” kind of guy, but I argued, in that post, against “throwing the baby out with the bathwater” since in this case, it would solve several serious environmental and economic problems simultaneously: Phosphate depletion, eutrophication, and carbon dioxide recycling, all using nuclear energy in a way that’s not too far from commercial experience, since lead reactors have operated. Unfortunately, Pooty-Poot, as Bush used to address Putin, controls access to much of the technical data, although it’s surprising how much has been published on this topic.

        So what I’m proposing is a floating nuclear powered chemical plant, not just another kind of nuclear electricity producing plant.

        For these reasons, my own focus on reactor design is with very high temperature systems.

        I believe with modern materials science we can go well above 900C, for which I believe, is the general region, that current HTGCR are being designed.

        Lead coolants, it seems to me, as I play around with various ideas and look at some historical work with fluid phased reactors, and also review the recent advances in lead compatible “MAX” phases, have a lot to recommend them. I’m not really, but the way, an LBE guy, I’m a pure lead guy, but that’s just my view. There are also other kinds of lead alloys that are extremely interesting to me, some of which we have long industrial experience, others less so.

        Thanks for your question.

        • Rick Armknecht says:

          O.K. — you are focused on high temperature applications. I get it.
          As regards “modern materials science” — any chance that the Uranium-Bismuth reactor is more possible?
          Also, the “others less so” category of lead alloys would include LME (Lead Magnesium Eutectic), I presume.

          • NNadir says:

            LBE is well known, and there is a lot of experience with it, so in a practical sense its infinitely more possible, since to my knowledge, no one has ever built a pure Pb cooled reactor, or one with other alloys, but I could be wrong. I believe the Russians are building an LBE fast reactor right now, if I have it right.

            This said, bismuth is a more expensive metal, and its presence leads to the problem of Po-210 accumulation, with the Po-210 suffusing into reactor materials, particularly the steels that have been utilized historically for LBE reactors. I note that the only real incident of “nuclear terrorism,” the Litvinenko affair – “nuclear terrorism” being something people are always going on and on about ad nauseum although its nowhere near as serious as oil terrorism – involved Po-210. But that’s not my concern; my concern is cost related and, I confess, a little bit of aesthetic issue. It turns out that in LBE, more bismuth – which is non-toxic – is transmuted into lead (via the 210 isotope) than lead is transmuted into bismuth. It has a nice marketing ring to it that lead is transmuted from a toxic element into a non-toxic one. (Trivial, I know.)

            The chemistry of lead is surprisingly interesting. One of the more marvelous things about this metal, among many other things is that it has a formal anionic state, in so called “Zintl salts.” These Zintl salts have some interesting properties that may have nuclear applications.

            (It should not be too surprising that lead is anionic since lead is a cogner, formally, of carbon.)

            The zintl anions of lead are generally actually complex cage structures, very cool. I confess to having not known anything about them, although they’ve been known for decades, until a few years back while mulling over some nuclear daydreams I was having, and begin studying various kinds of lead alloys, particularly those involving lead plutonium peritectics: Molten lead is not soluble in molten plutonium but does form peritectic solids. I have no idea if Pu/Pb peritectics have zintl like characteristics, but I do know of a number of other lead zintl salts that have multiple solid phases with some rather remarkable head capacities, particularly around phase transitions. I have the phase diagram of the Pu/Pb system somewhere in my files, but I’m not sure I can dig it up and post it here.

            I don’t know much about the magnesium lead system. Is it cool? Magnesium can be involved in some zintl chemistry, though not necessarily with lead; I don’t know. If there’s something special, I’ll check it out.

          • Rick Armknecht says:

            A little investigation into LME might intrigue you.
            The ratio is in the range of 95% Pb, 5% Mg (I forget if it is weight percent or atomic percent, and that is certainly going to make a difference). The South Koreans were looking at it as a coolant for a transmutation fast reactor, as I recall. The eutectic has a somewhat lower melting point than Pb (but nothing like LBE), it is less corrosive than LBE, and you won’t get any Polonium. Also, neither Pb nor Mg form carbides — a fact that could be of significance where graphite is in the reactor (as a moderator or a reflector).
            As regards Plutonium: isn’t molten Pu extremely corrosive? As I recall, it far surpasses LBE in that regard.

          • NNadir says:

            @Rick Armknecht.

            Most of the liquid plutonium work I’ve seen dates from several decades ago. I wouldn’t be surprised to learn that little has been done in recent years.

            In the late 1950′s and early 1960′s the LAMPRE reactor utilized an Fe/Pu eutectic, and then a Co/Pu eutectic. A ternary Co/Ce/Pu eutectic was under investigation when the project was cancelled. I recently pulled out of the paper archives at Princeton University library a very, very, very old paper on this system in which they actually built, and photographed, a three dimensional ternary phase diagram showing the composition and the “peaks” and “valleys” of the isotherms. No one would ever do something so wonderful now, the best one might hope for is a computer generated graphic.

            It is true that corrosion was a problem in the LAMPRE, and the system utilized tantalum crucibles, some of which failed along the welds. This system was a liquid Na cooled system, so basically it was very primitive. People tended to look at pure metals back in those days, and it doesn’t appear to me – I could be wrong – that much effort went into materials optimization. They found tantalum worked well enough and stopped there.

            I would never approve of a tantalum dependent system: The coltan crisis in Africa is bad enough just keeping the cell phones going; there’s no need to make it worse.

            Nevertheless, the tantalum dependence of the first iteration notwithstanding, it was a very beautiful reactor in some ways, with some very intriguing physicochemical properties that it seems were not explored very deeply. We certainly didn’t have the grades and understanding of Pu then that we have now.

            No one knew much about the advanced ceramic/quasi metallic systems we now know so much more about. Some of these systems will not prove suitable, because on top of the basic phase systems, we need to consider the particulate radiation. Some ternary metalloceramics, the “MAX” systems of which I am increasingly fond, are known to become amorphous when exposed to high dpa, including the very famous Ti3SiC2, system, but I suspect that even among these there may be an opportunity for self annealing with clever management. In any case we are at the dawn of a new age in materials science, including some very remarkable refractories that they couldn’t have even imagined in the mid-20th century.

            I note too that these early systems operated with Pu grades that had very narrow isotopic vectors: We simply didn’t have oodles of reactor grade Pu then, as we do now. Thus their energy density was very high compared with what we might do now. This was, in fact, the rationale for searching for fuel eutectics, the high volumetric energy density of Pu. This makes, it would seem to me, a big difference. It may be that this type of system might be able to utilize Pu from MOX used fuel. My understanding – I could be wrong – is that even the French don’t really want to play with this plutonium with a highly degraded Pu vector.

            I’ve never actually looked at the IFR work in any detail. It may be that they did a lot of investigation of this issue. I tend to have a “fuggetaboutit” approach to sodium cooled systems.

            Thanks for the advice on the Pb/Mg system. I’ve looked briefly at the related, and industrially well known Pb/Sr system – utilized in lead acid batteries – but it didn’t inspire me in any way. I will check out the Pb/Mg system on your advice, if and when I get the chance.

          • NNadir says:

            Rick: I’d like to thank you for pointing to this very interesting system, Pb/Mg.

            The binary system apparently has two eutectics, one at 466C and the other at 249C. This is very different than the Sr/Pb system.

            A number of ternary systems have been investigated as well, and I’ll be looking into some of these I’ll be looking into as well.

            Just for the hell of it, while I had the ASTM database up I looked at the binary for Mg/Sr which has a eutectic at 426C. Another cool system, I think. Sr is pretty transparent to neutrons, and it’s very easy to get self heating lots of it in the form of Sr-90.

            I know that Mg was important as a cladding material in early British reactors, but I don’t know off the top of my head, much about its nuclear properties, but thanks for the lead. It’s a cool system.

            Thanks again for the stimulating suggestion.

          • Rick Armknecht says:

            NNadir,

            Thanks for your kind post.
            Magnesium’s nuclear properties include a very low thermal neutron capture cross-section. As for a Mg/Sr eutectic: the use of Sr-90 recommends itself beyond the self-heating aspect. When the Sr-90 is removed from SNF, the heat of the spent nuclear fuel is reduced by about half. That would certainly be welcomed by anyone who was storing the SNF rods (which rods would, of course, be reformed into a more storage and transportation-friendly geometry after the “hot” isotopes were removed).

    • Rod Adams says:

      @NNadir

      My former employer, the US Navy, is working diligently on the chemistry of creating artificial hydrocarbons out of dissolved CO2 and hydrogen released from H2O. Of course, that process is endothermic, so it needs a reliable, low cost, energy dense heat source.

      In its press released about this project, the Navy doesn’t admit how much it knows about nuclear energy and operating floating nuclear power plants.

      http://www.nrl.navy.mil/media/news-releases/2014/scale-model-wwii-craft-takes-flight-with-fuel-from-the-sea-concept

      I have a little inside information about the efforts; my last job on active duty was in the OPNAV office responsible for funding fuels and fuel research.

      The West Virginia Coal Association is doing a pretty good job of keeping up with the developments in this area.

      http://www.wvcoal.com/research-development/us-navy-harvests-co2-from-seawater-for-hydrocarbon-synthesis.html

      • NNadir says:

        I’ve seen this work and read a number of related papers on this topic.

        It’s certainly interesting. I put my remarks on it this morning in response to a recent (long after the publication date) comment that someone put up, asking about that process.

        What’s very intriguing is that the method relies on electrochemically driven partitioning of salt solutions (seawater) into HCl and NaOH, both of which can be entered into hydrogen cycles as add-ons, particularly metal based cycles, although I haven’t seen this discussed in the literature.

        I’m writing a very funny piece on plutonium as a hydrogen cycle catalyst. You need to have a certain sense of humor to appreciate it, but I’ve always been a guy who laughs at his own jokes, generally because few people get them.

        More seriously I’m not sure that the Navy method is adaptable, economically, to a billion ton a year scale though. It seems unlikely to me, but I’d love to be proved wrong.

        • Engineer-Poet says:

          If I’ve done my calculations correctly, the Navy method requires about 1 MJ/mol just to extract CO2 from seawater.  I suspect that you get at most 1 mol of H2 in the process, and you need another 2 moles to reduce the CO2 to (CH2)n.  Widespread use would stumble just on the losses in the process, making relatively expensive energy into far more expensive hydrocarbons.

  8. Andrew Dodson says:

    There is going to be a serious issue with transmitting significant amounts of AC power by cable. Your capacitive charging currents are going to severely limit the distance at which you can couple to an existing grid. There is a reason we suspend power lines high up in the air! The dielectric constant of water is a significant obstacle.

    I suppose we could build HVDC interlinks on the beach and float our nuclear plants around to them…

    or maybe this is just more shenanigans distracting us from implementing simple safe nuclear power?

    • Engineer-Poet says:

      Dielectric constant isn’t as big an issue as you might think.  Generating with lagging power factor is rather easy.  Line inductance and inductive losses are another matter.

      If this problem needs to be dealt with, perhaps cycloconversion to 15-20 Hz 3ψ would be simpler than HVDC; both inductive and capacitive losses are proportional to frequency.  Where you need to connect to the existing grid, you cycloconvert right back.  My understanding is that a 3:1 frequency ratio is about the least you want for this, and as a bonus you’d get a “one size fits all” generation system which can hook to either 50 Hz or 60 Hz grids on shore.

      • Engineer-Poet says:

        That should be 3φ, not 3ψ.

        • Eino says:

          From Wikepedia:

          “Long undersea / underground high voltage cables have a high electrical capacitance compared with overhead transmission lines, since the live conductors within the cable are surrounded by a relatively thin layer of insulation (the dielectric), and a metal sheath”

          http://en.wikipedia.org/wiki/High-voltage_direct_current

          Looks like ELI the ICE man has a big C underwater.

          Maybe – instead of generating at a low frequency like old time equipment, you could just generate with a DC voltage and invert it on shore. I don’t think the rectification and inversion would be any more complicated than changing the frequency.

          • simple touriste says:

            Like IFA 2000:

            The HVDC Cross-Channel (French: Interconnexion France Angleterre) is the name given to two different high voltage direct current (HVDC) connections that operate or have operated under the English Channel between the continental European and British electricity grids.

            The first Cross-Channel link was a 160 MW link completed in 1961 and decommissioned in 1984, while the second was a 2000 MW link completed in 1986.

            WP: HVDC Cross-Channel

            Doable, but costly!

          • Engineer-Poet says:

            The English channel is 20-odd miles wide even at its narrowest point.  These plants would require cables less than a third of that length.

            The rectifier/inverter stations are a major cost for HVDC transmission, and make it uneconomic below a certain length.  I have no firm knowledge whether cycloconverters are much cheaper than inverters, but given what I’ve read about large electric drives I suspect that they are.  Cutting the frequency by a factor of 4 cuts reactance losses by the same amount, effectively multiplying the feasible length of an underwater cable by the same factor.

            Making the off-shore power station “plug-and-play” anywhere in the world, regardless of grid frequency, is a bonus.

          • kaya says:

            Always thought that with this shale gas drilling tech surely they can drill from france to the uk and instead of collecting and transporting gas just pull an AC or a DC line through it.

            Cheap way to interconnect some nations rather than the far more expensive under water method which would cost £2B for a 2GW line

            hell why isn’t it used to connect one gss market to another rather than the huge underwater pipes that take many years and many billions to build.

          • Rick Armknecht says:

            Isn’t the Estonian grid connected to the Finnish grid via a cable running under the Gulf of Finland?

    • kaya says:

      In the uk there are now many offshore wind plants which are 10-20-30 miles out and they are connected with AC underwater so it cant be a huge issue.

      also even if it were you could just pile some pylons onto the sea and suspend your cables. 20km out might only need 20 of them. Like the bases of wind tirbines only much smaller in diameter as they dont need to carry so much weight or withstand so much wind stress

  9. praos says:

    Have these guys ever set sail? If you have a floating structure, give it a boat-like form instead of making a clumsy drum and leave it to mercy of wind & waves. Oil platform is a poor model, being fixed to sea floor, but even it is legged, not compact, to mitigate the fury of the elements. You, Rod, as an ex-submariner, plying the oceans in deep-under tranquility, obviously have little to no idea how furious the waves up there could be.

  10. Herschel Specter says:

    Today US nuclear power plants are very expensive to build. However, other countries, like China and South Korea, produce new economical nuclear plants, some of which are modern versions of earlier US designs, but at a fraction of the costs we incur. Part of these lower costs is due to using modern factories to build major sections of these plants from standardized designs and part of the lower costs is due to advanced construction technology. However, much of the cost reduction in these highly capital intensive power plants comes from better financing, a subject we fail to talk about. The 2010 OECD lifetime levelized cost comparisons, in US dollars per megawatt-hour, make this clear:

    LEVELIZED COST

    Country, Reactor type investment money@5%, investment money@10%
    S. Korea, APR-1400 29.05 42.09
    China, AP-1000 36.31 54.61
    US, Adv. Gen III 48.73 77.39

    The decrease in levelized costs for nuclear power plants due to low interest money is profound. At a 5% cost of money, instead of 10%, US customers could get 1600 megawatts of nuclear capacity for each 1000 Megawatts they paid for.

    China and Korea have improved on earlier US designs, while we have languished. A new nuclear plant, at a 10 % interest rate and using US outdated manufacturing and construction technology, is 266 % more expensive than a similar plant built and constructed by South Koreans. The result is that South Korea, Russia, and now China, are offering nuclear plants for sale worldwide. South Korean leaders have predicted that their nuclear sales will eventually bring in more money than the sale of their cars. In spite of Chernobyl, Russia is successful in the international nuclear power plant market, by offering attractive financial arrangements to its customers. Perhaps we should encourage the South Koreans to build nuclear power plant factories in the United States, much like they build Korean cars here, employing American workers. With a standard design and a set sales price, it should be possible to attract investment dollars at low interest rates. Perhaps we should do our part by getting firm orders for 20 or so new standard nuclear plants from the American utilities at a fixed sales price to encourage the South Koreans to built in this country.

    • Eino says:

      Good point Mr. Specter:

      Technical people give their thoughts to Three Mile Island for the near demise of new US nuclear construction. However, it was also the financing that killed the WPPS plants, Marble Hill, Zimmer, etc. Inflation was still riding high in those days.

      “Perhaps we should do our part by getting firm orders for 20 or so new standard nuclear plants from the American utilities at a fixed sales price to encourage the South Koreans to built in this country.

      It may soon be time for new nukes again. Many coal plants are shutting down and people want their lights and heat.

      • kaya says:

        The problem with nuclear power is that CCGTs are brilliant

        you can man a 1GW CCGT 24 hours a day every day with just 40 men. The same nuclear plant needs as much as 1000 men in the USA.

        The difference of nearly a thousand men means the nuke has to pay 70 million dollars more in wages (assuming average wages are $70k for power plamt workers).

        so new nukes need to operate with far fewer people than old nukes.

        also a 1GW CCGT needs to dissipate about 700MW of waste heat. Some of that is via hot gas and the rest is via hot steam. Just for arguments sake the steam side might be 400MW

        Compare that to a 1GW nuke. It needs to disapate 2GW of waste heat and all of it via steam re-condensing.

        what that means is that with an inland plant a 1GW nuke needs to have a much bigger cooling tower because it needs to disparate some 5x more waste heat.

        the same is true for coal plants which are in between nukes and CCGTs in waste heat.

        This fundamental difference of 5x more waste heat and the need to deal with it is one of the big additional costs of nukes vs CCGTs and there isn’t a lot you can do about it

        if you like you can think of it as a nuke requiring 5 cooling towers whereas a ccgt would need 1.

        this is why most nukes are buolt on the cost or by a river so they can use that for cooling.

        Final big advantage of a ccgt is that it is far more compact and can be sited far closer to cities or even within cities. Again part of the reason is this fundamental difference in need to disapate waste heat.

        supercritical nukes would help in this regard by upping electrical efficency from 33% towards 45%. The additional benefit is that it would result in a decrease of waste heat from about 2GW waste heat to 1.2GW wate heat for a 1GWe reactor.

  11. kaya says:

    Floatig or submerged nukes (which nuclear subs and ships are) would also greatly help in the cost of the land.

    you need about 1km2 for a site on land. That much land in the UK would cost £5 milliom which is not a lot at all.

    However due to land being owned in smaller parcles by different individuals and the location for nukes very limited and controversial the sale/cost of nuclear land is typically much mch higher. For example the land to put the two new reactors that are planed for the uk supposedly cost north of £500 million ($800m dollars)

    That is a huge sum, up front, before you do anything. A cost sea based rigs or boats or subs would not have.

    For the planed uk reactors that means a cost of $0.25 per watt just for the land (plus interest for 10 years before its built)

    But the biggest benifit is perhaps the simple fact that you can produce bigger pieces for sea based project than you can via land. On land you are limoted to what a HGV or a train can carry. On a dockyeards you can produce far more of the plant in one piece.