A Proposed New Design of E-cat Boiler (Paul Dodgshun)

The following post has been submitted by Paul Dodgshun

A Proposed New Design of E-cat Boiler
(using the Operating Principle of a Once-through Boiler and with Steam Conditions suitable for driving a Steam Turbine)

Inspired by the realisation that the finned heat exchanger in the 1MW E-cat is a once-through boiler and having worked at two power stations that used different designs of once-through boilers, I started sketching. How would you put E-cat modules into a high temperature, high pressure boiler that was safe, cheap and reliable?

http://www.thermopedia.com/content/638/ Fig 3 was the main inspiration. A temperature of 400C in the lead in an E-cat is more than enough to exceed the critical point of water/steam (221bar 374C) and we do not want to be building reactors for those sorts of pressures. Steam generating plant in the UK was standardised at 540C turbine inlet temperature, so maybe this can be reached. Lead melts at 327C and boils at 1749C (https://en.wikipedia.org/wiki/Lead).

Take four E-cat reactor modules and place them on end in a square array. Draw a circle inside the square and another two outside. The circles are the plan view of a once-through boiler tube that spirals for the full height of the reactor modules. The once-through boiler tube is immersed in the molten lead shielding of the E-cats. All boiler tails can be above the lead level, as can the electric leads to the E-cat modules.

Producing spiral boiler tube bundles is easy; you just feed a long tube onto a turning drum of the required diameter. The tube materials can vary along their length, if needed, and so can the diameter.

The containment is a thermally insulated steel drum that provides support for the internals and a flanged lid for access but crucially it is not a pressure vessel subject to the steam pressure. The design can take heat from both sides of the fuel wafer and it may well be that the inner spiral would be the superheater and the outermost spiral would be the economiser.

The next size up could be an octagonal arrangement of fuel wafers and the ring of wafers could just keep on growing. Then you could put a second ring tank inside the first. There is no obvious limit to how big this arrangement could be.

Maybe there is a fatal flaw but I have not seen it yet.

  • GiveADogABone

    A set of spiral coils

  • Gerard McEk

    I think the E-cat is not suitable for temperatures far beyond 100C. For that you will need a hot cat or a multi QuarkX module. Using both types in one design seems possible. It depends if the QuarkX can be made sufficiently reliable.

    • GiveADogABone

      If the lead in the E-cat has melted, then the E-cat core is already over 327C. Bob G expressed a view that the lead reaches 400C. Perhaps a change of materials in the reactor would take it higher still.

      The 100C(or close by) limit must come from the water/steam side. That gets replaced completely. The real problem currently is the steam pressure in the casing. In no sense is the current casing a pressure vessel.

      A once-through boiler tube that will operate continuously at 540C at about 180bar has demonstrably been in service for thirty years in the AGR reactors in the UK. Use the same materials and the same conditions are available, reactor core permitting. An upgraded core is possible but would that still need the lead?

    • Warthog
      • GiveADogABone

        The lead also has a radiation absorption duty. We need a physicist to check but metal that is liquid at lower temperatures could be a benefit..

        • Warthog

          Stopping power for x- and gamma radiation is strictly a function of the atomic number of the metals in the alloy.
          (I did my PhD minor in Nuclear Science…no physicist needed).

          • GiveADogABone

            Which alloy are you recommending?

          • Warthog

            Which alloy will certainly be determined by the optimum operating temperature of the final design of reactor, so, at this point, any recommendation is wildly premature.

            My point is that there are many choices, up to the melting point of pure lead.

          • GiveADogABone

            If going for 540C steam, then 650C core might be about right.

          • Fedir Mykhaylov

            Let me ask – what is needed intermediate circuit with liquid metal coolant? All of the analyzes of spent fuel showed no long-lived radioactive isotopes. The high surface temperature of the fuel elements can be used such as a closed cycle gas turbine carbon dioxide, or cycle with superheated steam. Further developments apparently will use methods multistage transformation of heat into electric energy using hydrogen production and direct conversion of chemical energy into electricity in a fuel cell generating electricity using photovoltaic or thermionic converters. Apparently soon will be the main issue of thermal pollution.

          • Warthog

            Heh…designing power plant thermal circuits is not even in the footnotes of my CV. I have “generic science understanding”, but no more than that.

    • Gerard McEk

      I have asked Andrea to what maximum temperatures the Ecat can be produced. I hope we will know soon.

      • GiveADogABone

        ‘I think AR is saying that the Ecat reactor is not suitable for higher temperatures.’
        I agree and Rossi’s reply said :-
        ‘E-Cat of the type that has been operated during the 1 year test is designed for low temperature steam’,
        and I agree with that as well.

        Rossi goes on to say, ‘To get higher temperatures it is necessary the design used in the high temperature reactors.’

        This begs the questions, ‘Does he mean higher [steam] temperatures [and pressures]?’ and ‘What are the main design features of the high temperature reactors that produce high temperature [and pressure steam]?’
        I know of no information in the public domain.

        I cannot get past the ambiguity and I suppose a supplementary question would be,
        ‘Can the high temperature reactors produce steam at 165bar and 540C or something similar?’

        • Albert D. Kallal

          Rossi clearly means that the hot-cat would be required here. I don’t see any “fuzzy” here at all.

          The low temp ecats are not designed for higher temps and heat, so one would have to use the h-cats, or the ecatx for such higher temperatures.

          I don’t recall what temp the low temp ecat runs at, but the setup is a low pressure and low temp system.

          The higher temp reactor runs at about the melting point of nickel – 1350C. So for such high temperature cats there no reason why these higher temperature ecats could not produce steam in the 500C+ range, or even supercritical steam.

          So quite sure more then once the temperatures that the high temp ecats reach has been noted more then once.

          Albert D. Kallal
          Edmonton, Alberta Canada

          • GiveADogABone

            ‘The low temp ecats are not designed for higher temps … ‘
            Is the low temperature limit due to the
            1: E-cat reactor internals, or
            2: water/steam side, either the temperature or the pressure?
            What are the temperature limits of each?

            I completely accept that the current water/steam design is limited to about 130C/1.5barA. The proposal strips out the water/steam hardware in its entirety and replaces it with a once-through boiler tube that is capable of 540C/180bar. Even if the proposal only reaches 330C/125bar, it would match the PWR reactor design.

            We seem to have absolutely no information about the steam-raising performance of the Hot-cat, bar a vague statement that 600C steam (at unstated pressure) was produced. This proposal was an attempt to see how steam conditions that could be used for generation might be achieved.

            Apart from worries about a steam/water leak into the molten lead, I think the proposal is still valid. Maybe the Hot-cat uses once-through boiler tubes, arranged in a spiral, as well?

          • GiveADogABone


            [Rossi] stated that the energy was mostly if not all released in the form of radiation. This fact is critically important as it allows him to separate the heat generation mechanism from the energy generation component.

            The cores operate at somewhat greater than 600 C while the heat sink is substantially lower in temperature.

            Could the E-cat melt a hot dip galvanizing tank and hold the temperature at 450C? If so, then an immersed set of coils could deliver high pressure superheated steam.

  • Alan Smith

    Biggest problem I can see is maintainance and inspection. The whole ‘hot tube’ part of the boiler – and the reactor assembly – is either stuck in a chunk of solid lead (when cold) or immersed in molten lead when hot. The effect of a tube failure allowing steam to blow into a bath of molten lead is likely to be explosive- especially if the failure point is near the cooler ‘wet end’ of the tubes.
    Still, nice imaginative idea.

    • GiveADogABone

      There can only be one way to remove the boiler tubes and that is when the lead is molten, at a temperature a bit above 327C. The boiler design would clearly have to allow a clean lift of the coils and reactor fuel plates by an overhead crane. Would this be any more difficult than lifting big components out of a hot dip galvanising tank at over 420C?

      Safety is always an issue with boilers. We are talking about a steam/water leak from a pinhole to a guillotine failure in size. Exactly how it would behave I cannot say but it would need to be determined. A look at the safety case for the Sodium cooled fast reactor might give some clues.

      The way to stop backflow from the steam side is to fit a non-return valve. The inlet side with once-through boilers normally has an orifice with a substantial pressure drop in normal service for balancing tube flows. This also limits the water flow in fault conditions and can be backed up with a high flow trip. With inlet and outlet shut the contents of the pipe would discharge.

      Chemical :
      Lead virtually has no reaction with cold water or steam.

      Sodium cooled fast reactors have a Sodium/steam generator and that certainly does react chemically.

      • Alan Smith

        I wasn’t thinking about a chemical reaction, but of the sudden and explosive transformation of leaking water into steam. Anybody who has poured molten metal into a casting mould knows how violent this can be – more of a bang than a woosh! Although the inlet side does only have a small water inlet, you must remember that it has a very powerful high-pressure pump behind it- for the inlet water pressure must match or exceed the steam pressure in the tubes. Check-valve or no there is quite a volume of steam inside the tubes of a big ‘flash’ boiler like this.

        A side effect of this type of failure would be to pressurise the lead containment, too. More complication.

        • GiveADogABone

          I agree it is an issue. A look at the fast reactor safety case seems necessary.

  • Sean

    Just looking at the R.R. PWR 2 and 3 reactors, as parliament approved the renewal of the nuclear submarine deterrent yesterday. All you do is replace the core with an LENR core and the rest is done. Why try to re invent the wheel. Also found a free reactor simulation program that look like fun. http://getintopc.com/softwares/simulators/boiling-water-reactor-nuclear-simulator-free-download/

    • GiveADogABone

      Do you have ‘cunning plan’ for getting the electric cables to the fuel wafers?

  • GiveADogABone

    Hmmmm? Would the admiral in charge of naval propulsion systems buy this as a fully developed design? The Navy do like their engines to keep working.

    • Sean

      Look,, all we have to do is send the ECAT salesmen over to see the admiral, First impressions will count such as “no radiation and cheap to run” specially as governments are cutting their spending re USA & UK budgets. He could always offer a two for one sale. Try before you buy. Once you sell to one navy admiral, they will all want one or two of these. ECAT is a win win situation. Question is, when are we going to get out little units?. Your car is waiting for the conversion too.

      • GiveADogABone

        The UK Parliament voted to keep the nuclear deterrent a couple of days ago, so there is a big selling opportunity. The little people do not matter unless you are daft enough to ask them to vote in a referendum.

  • GiveADogABone

    According to [Rossi], this new E-Cat module can produce a steady output of 600C steam. In fact, it is asserted that the module being tested has been producing 600C steam for over forty days! When the test is complete, data from it will be posted on Rossi’s blog, The Journal of Nuclear Physics.

    Did it ever happen?
    This is a post from four years ago.
    You can produce steam at 600C and 1barA but it is not going to do a lot of generating.

    The PWR nuclear reactor operates on wet steam at about 330C 125bar.
    Would that be achievable with an LT E-cat core?

    • Ophelia Rump

      No, I don’t believe you can make steam that hot without pressurization. I cannot find a steam temperature to pressure calculator which will allow that.

      Further steam temperature pressure relationships are stable and can be derived from lookup tables.


      • GiveADogABone

        ## Watch this web page carefully. ##
        ## The page inserts the default saturation value and you do not want that ##
        Input Data
        Steam Pressure 1barA
        Steam Temperature[?] 600C
        Specific Enthalpy of Superheated Steam 3705.57 kJ/kg
        ## Looks right to me but check on the steam pressure enthalpy diagram as below. ##

        Saturated is no use.
        Steam at 1barA 600C is well into the superheated region.

        Websearch ‘steam pressure enthalpy diagram’
        Pressure-Enthalpy diagram

        The Pressure-Enthalpy diagram illustrates the relationship between pressure and enthalpy with curves representing temperature (T), entropy (s), specific volume (v), and dryness fraction (x).

        The dome-shaped curve represents the limits of saturation – within the curve, steam is saturated.
        Find the 600C temperature line
        Follow it down to pressure=0.1MPa (or 1barA) on the y axis
        The intersection is to the right of the arrows labeled B and C
        Drop a perpendicular to the x axis and read
        I make it 3700 kJ/kg or thereabouts.