Smaller nuclear reactors allow decentralized power - some critics not pleased 1


  1. @ Rod

    You state that ‘These days, the US is building small modular reactors in just 3-4 years – in factory settings and in a confined space.’

    Are you talking commercial SMR that are being sold for civil applications today ?

    I am surprised because my understanding is that the first commercial SMR will be delivered by Russia in 2017 using an offspring of their military technology.

    1. Daniel – there is a link in that statement. I am referring to our current construction program for the Virginia class submarine. I fully recognize that those small modular reactors are being built as part of a military vessel. However, the facts are the facts, and it would be difficult for anyone to assert with a straight face that a military construction project – especially one being conducted in the United States – is inherently more efficient than a civilian one.

      However, I have to admit that I know some of the people who have made the Virginia program a success and they are some very bright and dedicated folks.

      1. @ Rod

        This is one of my disappointments with the nuclear industry. Civil SMR could be behind us as we speak and the market in high gear in a renaissance era thanks to this concept.

        I can’t figure out where and why the industry missed the boat on this no brainer.

        But better late than never.

      2. @Rod, I’ve been wondering if there’s any technical or economic reason why ships such as destroyers or cruisers aren’t equipped with a nuclear power-plant. Can you enlighten me? Overkill, perhaps?

        Installation to decommissioning with no new fuel – amazing! There must be some very interesting and clever technology involved there.

        I’d be interested in your take on this paper about converting naval reactors to LEU:

        1. Michael,

          There is a recent CBO report that identified the amphibious assault carrier (straight deck carriers used by the marines-smaller than the Enterprise, Nimitz or Ford class carriers) as the most cost effective naval vessel behind the current submarines and aircraft carriers.

          The CBO report said this application was cost effective if the navy were to use one of the reactors currently used in the Ford class carrier and the cost of crude oil remains above $80/barrel. (A Ford class carrier uses two reactors but is a bigger ship and has more electrical equipment.)

          The problem with nuclear powered ships is the same as commercial nuclear-costs are front end loaded.


          1. There are historical reasons why the entire surface ship navy is not nuclear powered. Interestingly enough, there was a brief period of time in the late 1960s and early 1970s when Congress passed a law saying that all major combatant ships would be nuclear powered. The Surface Warfare Community – and some pals at GE and in the petroleum industry – came up with a novel idea to rename the 563 foot long hull being designed with four LM-2500 gas turbines as a “destroyer” to ensure that it was not covered by the law. Destroyers are considered to be small ships, not “major combatants.” That hull became the Spruance class destroyer, but the exact same hull form was later turned into the Ticonderoga class cruiser, still with JP-5 fueled gas turbines, but by then, the nuclear propulsion law had been overturned.

            Interestingly enough, the Defense Authorization Act of 2008 included the following language:


            (a) Integrated Nuclear Power Systems.–It is the policy of the
            United States to construct the major combatant vessels

            [[Page 122 STAT. 304]]

            of the strike forces of the United States Navy, including all new
            classes of such vessels, with integrated nuclear power systems.
            (b) <> Requirement To Request Nuclear
            Vessels.–If a request is submitted to Congress in the budget for a
            fiscal year for construction of a new class of major combatant vessel
            for the strike forces of the United States, the request shall be for
            such a vessel with an integrated nuclear power system, unless the
            Secretary of Defense submits with the request a notification to Congress
            that the inclusion of an integrated nuclear power system in such vessel
            is not in the national interest.

            (c) Definitions.–In this section:
            (1) Major combatant vessels of the strike forces of the
            united states navy.–The term “major combatant vessels of the
            strike forces of the United States Navy” means the following:
            (A) Submarines.
            (B) Aircraft carriers.
            (C) Cruisers, battleships, or other large surface
            combatants whose primary mission includes protection of
            carrier strike groups, expeditionary strike groups, and
            vessels comprising a sea base.
            (2) Integrated nuclear power system.–The term “integrated
            nuclear power system” means a ship engineering system that uses
            a naval nuclear reactor as its energy source and generates
            sufficient electric energy to provide power to the ship’s
            electrical loads, including its combat systems and propulsion
            (3) Budget.–The term “budget” means the budget that is
            submitted to Congress by the President under section 1105(a) of
            title 31, United States Code.”

  2. Rod. I agree with you. Everyone I have met with a responsible position in nuclear energy is a person who had choices about their careers. A person geta a mechanical engineering degree, a degree that opens many job paths, and then for grad school, choosea nuclear engineering. I have a chemistry degree, worked in renewables for years, and switched to nuclear. Nuclear people work in nuclear energy because we made that choice.

    Enough of this “shill” business! We are not “shills” protecting our jobs! Many opponents would have a much harder time with their job choices if the “nuclear opponent industry” didn’t exist.

    1. Once again Rod has reconnoitered enemy territory, in this case “Earth Island Journal”, and employing weapons of fact, logic, and reason, taken the battle to him on his own turf.

      I see it as unfortunate however, and in the long run perhaps decisive, that the ones with the most to lose or gain economically in this battle, the so-called nuclear industry, relies on talented, dedicated, but unpaid amateurs to do most of their fighting for them.

      In a business where you are always only one headline away from losing a ten-billion dollar asset (current replacement cost), why are they unwilling to commit even 0.1% of that annually per reactor for public relations, educational advertising, or outreach?

      The initiative-killing rules are made and enforced by the regulators, who fear only their politician masters. The politicians fear only the voters. The voters as a whole believe whatever the mass media tell them to believe. The mass media is essentially owned by the fossil fuel interests, who provide massive sponsorship.

      To ever have the leverage they need, the nukes have to raise their positive visibility in the public marketplace of ideas by at least an order of magnitude. This takes big bucks. After Fukishima, will they now open their checkbooks, or will they go back to business as usual, hoping this latest crisis will quickly recede deep into public awareness and then they can go back into their habitual practice of hiding and hoping no one notices them?

  3. “Is the minor convenience of allowing the present generation the luxury of doubling its energy consumption every 10 years worth the major hazard of exposing the next 20,000 generations to this lethal waste?”

    I dunno. Does it really matter how lethal it is to anyone for how long when two thousand feet down in solid granite?

    “The Fukushima disaster has severely hobbled the atomic industry’s hopes for a big-ticket nuclear renaissance…The planet can’t afford nuclear energy – be it mega or mini.”

    We have to — we must — lay aside the reactor design arguments while Rome’s burning and take the bull by the horns just to get the public to accept ANY nuclear energy, period. We need to get prompt mass attention to de-demonize nukes and that’s the media. All my research shows that the “Varney” and “Cavuto” business shows on Fox Business are more receptive than most to entertaining outside insights. Libertine John Stossel is also a good unbaised hit. Fox News seems the news service with the least intrinsically anti-nuke “new world progressive” coat tails from the ’60s. With Rod’s permission I will launch off a (hopefully not one man) email drive to these shows to implore them to extend Rod and/or Will Davis of Atomic Power Review guest invitations and hopefully others will follow. If there’s an atomic worker’s union or clearinghouse I hope their membership hops on board missions like these. Please follow my emails everyone.

    James Greenidge

    1. James – you have my permission. I do not know much about the shows that you mention – other than Stossel’s because I have posted several clips of his on Atomic Insights. I am sort of old fashioned – I like to read rather than to watch television. That is why I spend so much time on blogs, news sites, and twitter instead of in front of the passive screen.

  4. This seems likely to be the most “on topic” post to place this question – though I asked it a few days ago on the post about the debate challenge that Steve Kirsch made to MIT about Fast Reactors:

    Will someone please provide me some source of answer to the proposition that using sodium coolant is an inherently bad/dangerous design?

    I do know from a demonstration in junior high that sodium (at least pure Sodium) will definitely spontaneously combust, very vigourously, if it ever comes in contact with water. I believe it will combust, though less rigoursly, if it comes into exposure to air.

    So, how do nuclear engineers address this problem for designs like the PRISM SMR? Do they form a sodium compound which is more stable, and so will not be as inflammable? What’s the answer?

    Please, I’d really like to know how you can ensure that a sodium cooled plant will remain safe?

    1. Jeff – I am not an expert, but the basic technique involves keeping the reactants separate. If water and sodium combine explosively, then keep the two of them apart. If you want to build a steam plant that is heated with liquid sodium flowing through pipes, make the pipes double walled with a leak detection capability between the two walls.

      If you need to gain access, put a purge of N2 gas on top of the sodium to prevent contact with air.

      As is the case for a PWR where the coolant is H2O at elevated temperature and pressure, having a piping leak in a sodium cooled reactor can spoil your day. The engineering solution is to prevent leaks through excellent quality control and maintenance processes.

      Finally, design systems so that if leaks do occur, with the potential for fires and explosions, strive to minimized the potential consequence of the reactions.

      The operating record of the sodium cooled EBR-II indicates that the challenges are solvable, even if the system is not absolutely perfect. Good enough is good enough to prevent significant equipment harm or human health risks.

      1. The main thing I worry about are corrosion (which should be able to be monitored through inspections, and corroded parts replaced, so that’s not such a major concern), and massive physical failure due to something like an earthquake or large explosion in very close proximity to a nuclear plant (I sometimes do worry what would happen if in the future, in a wartime scenario, a foreign power decided to drop bombs/missiles/artillery shells on a nuclear plant; it might seem a very unlikely scenario, I grant, but I can’t seem to shake the idea that it’s at least in the realm of possibility).

        I figure that engineering can deal with almost every ‘ordinary’ problem – like you say, use well sealed pipes, and inert gasses to isolate the sodium coolant.

        I’d like to know if the reactors are designed in such a way that it’s probable that even a full-scale sodium fire couldn’t cause damage/release of any significant amount of radioactive material?

        1. @Jeff:

          My best response with regard to your concerns about corrosion is to quote a statement from an email that I saw on the IFR group thread a couple of days ago. I have removed the names to keep the discussion private:

          “I will leave most of Mr. Y’s commentary to be addressed by others, but one sticks really deep in my throat, namely his statement on corrosion problems with sodium:

          “Sodium is likely to have all sorts of issues in terms of corrosion– I know, I spent most of my masters degree looking at alloys that could survive liquid sodium environments.”

          Utter nonsense!! I worked on the design, fabrication, and construction of the EBR-II in several areas, including the large sodium filled Primary Tank (which contains the entire primary system) and many of its penetration assemblies. I was absolutely amazed when my colleagues in Idaho showed me photographs of this tank taken during decommissioning of EBR-II, after draining the sodium that it held at 700F for 40+years. The surfaces of the rather conventional stainless steel Type 304 material used in this vessel were in pristine condition. You could even see evidence of some of the welder’s original ink markings made in 1960 quite clearly!!!

          Someone needs to tell Mr. Y that corrosion is a very big problem—for the LWRs. Just ask any LWR plant operator.”

        2. One key point – because of the attractive heat transfer and other characteristics of sodium, the physical design of the plant should be fundamentally different to a LWR – typically, using an unpressurised “pool” in which the core and ancilliaries are suspended, rather than a pressure vessel and pipework circuit. That’s inherently far more seismically safe, and has the rather attractive quality that heat removal from the core can be pretty much entirely passive – no pumping, relying instead on natural circulation and conduction.

          The secondary sodium circuit as described before would (again typically) have the hot end” heat exchangers submerged in the pool (at the periphery), and the cool end (where steam is raised) in a physically segregated space.

          Sodium, in UK experience wasn’t that aggressive an medium, once some basic issues concerning embrittlement in welds in stainless steel were solved. We ran the Dounreay Fast Reactor and Prototype Fast Reactor for 20 years each.

          Frankly, a bigger problem is thermal stressing of secondary components, due to the sheer conductivity of sodium.

      2. Rod and Jeff,

        I would like to make one more suggestion concerning sodium cooled reactors. I can understand the problems when sodium cooling is used with typical steam plant electricity generation. Therefore, I would suggest that for this type of system we move away from steam generated electricity to closed Brayton cycle turbine electricity using an inert gas as the working fluid.

        The proposed Adam’s Atomics Engine Pebble Bed reactor uses this method for electricity generation. Furthermore, the proposed LFTR designs tend to envisage a second molten salt heat exchanger loop that then heats inert gas for the Brayton closed cycle.

        Further advantages of the Brayton cycle besides are increased safety by removing the water from the system, increased efficiency due to higher working temperatures and the ability to use air cooling. Having air cooling allows smaller reactors to be sited in more places especially those short of water.

        Joe Heffernan

    2. Rather simply – you don’t allow the sodium that’s in the main reactor circle/pool the possibility of direct contact with water. All the sodium-cooled LMFBR designs use a design where there’s an intermediate sodium circuit – the sodium in the main vessel/pool gives up heat (via heat exchanger) to sodium circulating in a segregated system, and then that circuit provides heat to a conventional steam generator.

      It’s not especially problematic – the heat transfer characteristics of sodium are so good that losses are minimal.

      Having said that, it’s a complication that can ideally be done away with – which is why alternate liquid metal coolants (like lead or lead-bismuth) may well prove more reactive.

  5. Now calm is what we need lads! Calmly raise the Jolly Roger and fire up the modular reactors. Taking prize ships and installing our reactors in them. They will have no choice but use nukes in view of the mess they have created on the world’s ponds.

  6. Sodium and water:

    2 Na + 2 H2O -> 2 NaOH + H2

    The reaction produces sodium hydroxide (typical drain cleaning agent), hydrogen and some heat. The combustion observed in school chemistry classes is due to the burning of hidrogen in air.

    The sodium in the secondary loop of a sodium-cooled nuclear plant cannot make contact with air and water at the same time. If a leak develops inside the heat exchanger, hydrogen will form, but there is no air inside the exchanger. If a leak develops outside the
    exchanger, the sodium itself will burn but it will not touch water and there will be no hydrogen. Hydrogen in air is the real hazard and that’s not realistically possible. Of course, all these sodium hazards are far away from the reactor and the primary sodium coolant.

    The Russina BN-600 has been operating for 30+ years now. There have been leaks, sodium/water and sodium/air interactions as described above. These incidents have caused only minor damage.

    With that said, I would recommend pebble beds for small reactors. Fast, sodium-cooled reactors have their place but they fit better in centralized and well protected settings.

    1. Sam,

      The Nautilus was, of course, the first nuclear submarine. The second one was the Seawolf. It had a sodium cooled fast core rather than a PWR like was in the Nautilus.

      Rickover had the sodium core pulled after about two years and had it replaced with a PWR. I think he would agree with you that, if we are to use sodium cooled reactors, they should be land based.


  7. I just let a comment on the article mentioned above. Let’s see if it comes through, If not, here is a copy.

    Interesting, the exposure of people in Japan to the dangerous hazardous, terrible worst ever radiation release has killed no one so far. The contamination of the areas leaves a background radiation less than many areas of natural radiation.

    As I have studied this topic I found that the more dangerous radiation is, the more quickly it goes away. I am now understanding that Nuclear power is one of the safest ways to generate power, far safer than hydro, or coal. I notice that in your list above, the number of deaths associated with Nuclear in any way are fairly small. In the last year, deaths from Natural Gas explosions, coal mine collapses, and exploding oil rigs are about equal to the 55 year total you have given for Nuclear, excepting Chernobyl. I challenge your death toll numbers for that. The estimates do range from about 50 to more than a million. Why the vast difference? Because one source (a group of UN research teams) is counting actual deaths, while the other projects the “possible” deaths in an area using who knows what methods.

    When a hospital can use radiation to cure a patient, why are we frightened by a much much lower level of radiation from Nuclear power?

    The areas around Fukushima could be resettled quickly without harm to the people. There might be a few areas of more intense radiation but these are easily identified and avoided. Within 30 days most of the radiation was gone (I-131). What remains is minor and fading – as is the nature of radiation, it is what MAKES it radiation – it fades away.

    I have lived in areas without electricity. I have struggled to carry water up 6 flights of stairs when the power was off in my apartment. I have helped build wells in areas without water and know how difficult it is to move water without electricity. I have friends who are doctors in a hospital where power interruptions come any time and are sometimes fatal during an operation.

    Nuclear power provides the safest and most reliable electricity in the world. We need more of it and Small Medium Reactors would be a blessing to the world.

    Here is a link to a Nasa Engineer who has a Master’s in Nuclear Engineering talking about the “waste” of nuclear fuel. What it is, how long it lasts and how valuable it is.

  8. Again, you are taking the discussion to the anti-nuclear sites, where there is more of a chance to convince people not already convinced.

    I can’t reach right now, I get a message “down for maintenance”. But it would be interesting indeed if the American government shared the view that low level radiation is good for health.

  9. The appeal of calls for energy efficiency is that it touches on deep-seated Protestant morals that still are an active undercurrent in Anglophone culture: Who will argue with “waste not, want not?”

    The problem is that all in all there is very little energy waste among the major users of power in industry, and in other large scale applications. The have known for decades that money saved on energy costs go right to the bottom line, and as a consequence there is not much ‘waste’ there to cut. Residential consumers comprise about 87% of total end-use consumers serviced by electric utilities and but consume only about 35% of total electricity produced, while there may be some gains to be made in that sector, they will not be as significant as supporters think.

    1. @DV82XL – The calls for improving energy efficiency also worked very well at the time that Lovins started issuing them because so many decision makers were influenced by the extreme poverty caused by the Great Depression. My parents were both raised during the Depression in families that often did not have two nickels to rub together. They were adamant about avoiding waste, even at the expense of a lot of time to save very little.

      The call also appeals to people who have a superficial introduction to thermodynamics – they are offended that 2/3rds of the energy input into a steam plant has to be wasted, but that is the only way you can make heat flow to do work. As the temperature of the heat source approaches the temperature of the heat sink, capturing the energy requires larger and larger equipment and slower rates of capture to the point where there are no more returns to be gained.

      However, design engineers who work for equipment manufacturers will gladly take customer money for efforts to squeeze just a little more efficiency out by adding another large heat exchanger into an already complex and expensive piece of machinery.

    2. I once made that same argument on Daily Kos, and the response was “today’s corporate bosses don’t look beyond the quarterly balance sheet, and wouldn’t think of spending a lot of money up-front in order to save money in the long term through greater energy efficiency”.

      1. @George:

        There are a lot of commenters on Daily Kos who have about as much experience in corporate decision making as Amory Lovins. In other words – they have no idea what they are talking about. If there is a reasonable chance at a decent payback, companies make the investments. If the ROI stretches way out into the future or if it is uncertain because the predicted gains are evaluated by the company technical decision makers as not being as high as the sales pitch claims, companies will logically decide to invest their money somewhere else.

        That is logical. As much as a rail against the short term decision making tendency of corporate leaders, I recognize that they are not stupid and not so short sighted that they will fail to invest when there is a good chance of a significantly positive return as described by Lovins catchy phrase of “hundred dollar bills on the ground”. Anyone will bend over and pick those up – most of us make different decisions if the money on the ground is pennies or quarters or if the hundred dollar bills are buried deep in an uncertain location.

      2. George.

        I believe the same thing is true about fertilizer runoff. Farms use more fertilizer than homeowners, because there are more acres of farmland than lawn. However, homeowners tend to be far more cavalier than farmers about using too much fertilizer, useless amounts of fertilizer. For a homeowner, the fertilizer cost means little, if he or she is very proud of the lawn. Fertilizer use is not a bottom-line issue for the homeowner. For farmers, it is. A lush green lawn can be a source of nitrate run-off and can be a target for conservation. On the other hand, you have to try to get conservation one lawn at a time….

        This is parallel to the use of energy by homes versus businesses.

      3. Actually, the large American front lawn is environmentally damaging in two other ways besides the fertilizer issue. It leads to excessive water use (especially in arid regions such as the Southwest — if I had my way, water usage in such regions would be heavily taxed, and the tax revenue used to build nuclear desalination plants) and also to an even greater dependence on cars (because the amount of land wasted on lawns forces houses to be further apart from one another).

        Take a peak at Old Urbanist’s Setbacks, Suburbs and the American Front Lawn, which also includes some useful pictoral contrasts between American and European suburbia.

  10. @Daniel – the other problem with Lovins’s brand of “energy efficiency” is that he has a completely ill informed view – despite supposedly being an “energy guru” for more than 35 years. He often makes statements indicating that he actually believes that there is a way to overcome basic thermodynamics – like the absolute limits on thermal efficiency imposed by the Carnot cycle. I have listened to his talks and read his material very carefully – he does a lot of hand waving, and spouts a lot of numbers, but he seems to believe that entropy is a mere inconvenience that can be completely avoided by smarter designs. He is the kind of “efficiency” expert who grossly undersizes an HVAC unit and then asserts that the poor insulation in the building is the reason it feels so damp and muggy on a hot day. Following his advice is a great way to impose a “sick building” by sealing it up so tightly that toxics can never escape.

    He also makes completely ridiculous statements that even smart, but non technical, non practical folks like James Hansen fail to see as non-sensical. For example – in the material that I linked to in the “aside” near the beginning of this post, Hansen says the following about an encounter with Lovins:

    “When I saw Amory most recently and queried him, he affirmed that no tax was needed. He said that hundred dollar bills are being left on the ground by companies that ignore energy efficiency.

    Indeed, there is still great potential in energy efficiency.”

    Anyone who has ever had any responsibility for the profitability of a company would immediately recognize the absolute absurdity of that statement. What company would fail to pick up “hundred dollar bills”? As DV82XL mentioned in his comment – there are no “hundred dollar bills” worth of energy efficiency laying on the ground at any company.

    The ground at any reasonably well-run company is swept pretty carefully when there is any money to be gathered. There might be a dollar bill or two in hard to reach places, but getting them out probably requires buying a several thousand dollar super wham-a-dyne vacuum cleaner built out of carbon fiber (supplied by Fiberforge) whose energy efficiency payback is long and uncertain compared to the broom that has been serving its purpose for several years.

  11. And they’ll be even more hostile to the idea of reducing the world’s population down to 1800s levels!

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