38 Comments

  1. Google nicely gave me an automatic translation from the Indonesian. However, sometimes I have to guess at what the translation is saying. The following paragraph confuses me. Could someone smooth out this translation especially IRR and 1.25 million?

    “Prototype project of 500 MW will require capex of USD 805 million with IRR of 13% based on the development period of 7 years (including the preparation of 2 year) plus 32 years of production. After the license of the Bapeten rising, construction of NPP T-MSR 1000 MW can be started with Capex amounted USD 1.25 million and IRR of 23% over the two years of construction plus 32 years production.”

  2. Godspeed!

    So is it reasonable to take the 2019 data as when the first prototype build is aimed to be started and 2025 the date of it’s completion … or would that be sooner?

  3. Thorcon would seem to have the best nuclear island concept, while Terrestrial Power appears to have the most advanced concept for the replaceable core unit.

    A marriage of the two would seem optimal?

    Perhaps some mutually advantageous licencing would help cut costs on both sides?

  4. I have had similar thoughts because both are molten salt burners with a replaceable core. I see Terrestrial as modules sized for truck/train delivery and ThorCon as modules sized for barge only delivery.

    At the present time Terrestrial is building a corporation of North American executives who plan to pursue Canadian and US regulation. I’m betting ThorCon will/is building a corporation with people from Indonesia and South Korea (maybe one from India too and is pursuing Indonesian regulation.

    There are two reasons why they should not join now:
    1. We need both business models to be tested. Both are likely to fail at least partially. But at least we get two shots at goal.
    2. We need both technologies to be tested. Dump tank or no dump tank? NaBe salt or Terrestrial’s mystery salt? Off-gas collection and processing method?

    They might cut costs by sharing motor or heat exchanger information.

    My prediction:
    One of these companies will actually build a prototype reactor. The other’s technology will be acquired by the first-to-market company.

  5. See page 58 of Indonesian document.

    Martingale sold ThorCon IP to ThorCon International located in Singapore. I think just getting organized but same owners. There’s also a ThorCon USA located in Stevenson, Washington.

  6. Are you related to Chris Uhlik, who is part of the ThorCon development team (formerly of Google)?

  7. Oh, and I certainly look forward to having more power-producing advanced reactors around the world as well.

  8. Tough to camouflage a name like Uhlik, even with a first name as common as Joe.

    🙂

  9. Getting a ThorCon reactor in operation will shake the world.

    That’s Tom Blees on the left, isn’t it?

  10. @Timothy Maloney

    Agreed on shake up. Tom Blees is not in the photo. He has a beard and is several inches taller than anyone in the picture.

  11. @Joe Uhlik

    I’m glad you have joined the discussion here. I met Chris about ten years ago when I visited the GooglePlex. He is one of the smartest persons I’ve ever met.

  12. Personally I find TE more convincing but I wish both of them all the best. What is really strange about TC is that the fuel lifetime is twice the can lifetime. Why go through the bother of pumping highly radioactive fuel (after at most weeks of cooldown) between cans for the benefit of reusing the fuel once? Makes no sense!

  13. Not convinced by the drain tank benefits either. Too slow as a means of emergency chain reaction shutdown as reactivity only goes down when level reaches top of moderator. Emergency permanent shutdown easier achieved by releasing boron salt into the fuel through freeze valve. Passive decay heat removal from the pot with fuel in place necessary anyway.

  14. With ThorCon the graphite is used up in 4 years. Instead of just replacing the graphite, ThorCon replaces the “can” (reactor vessel, heat exchanger, and piping) but by moving the fuel to a second can, the fuel can be used for another 4 years.

  15. The function of the drain tank is not to stop the the chain reaction. The chain reaction is stopped because the fuelsalt expands pushing fissile atoms out of the fissionable volume. But, if all the ways to remove heat from the pot fail, the pot will continue to get hotter even after chain reactions stop causing the fuse to melt.
    The drain tank is made of expensive steel who’s melting point is higher than the pot. The drain tank is shaped to radiate heat better than the pot.

  16. $1.25 Billion US CapEx for 1,000 MWe of capacity and 92+% availability. If they can do it – that would definitely shake things up. Good luck and get to it for the Indonesian people (and the entire World) surely need it.

  17. Yes, I understand the concept but not the rationale. As far as I understand, after 2 cycles the fuel is allowed to cool and then shipped back with the can in order to reprocess the fuel and reuse parts of the can.
    Why not put less fissile into the fuelso that it only lasts 4 years, and always send the whole sealed can back to the factory after 4 years operation and 4 years cooling? The fuel is a relatively small part of the capital expense. Being able to re-use some of the fuel sooner is unlikely to justify the extra complication of pumping hot fuel between cans.

  18. Thanks, this makes sense. Is this only a last ditch safety measure? Is there a way to pump the fuel back up or is it time for a new can and new drain tank if this happens?

  19. Unlike a solid fueled reactor, it is not necessary to put excess reactivity into to initial requiring a poison to counteract the excess or the use of control rods. Instead a little over 4 liters of fuel is added each day to keep enough fissile to sustain the reaction. NOT having excess reactivity increases safety and reduces cost.

  20. The initial charge is about 40 tons of salt, 12 tons of thorium, and 3 tons of 20% uranium. Each day 15 kilograms of fuel-salt is added to keep the system barely sustainable.

    Now my answer is my answer becomes speculation.

    I think the dump tank is a last ditch safety device. If used, the can is shipped back to the factory and replaced with a new can and a new fuse.

    My guess is that 15 kg fuel-salt spills out each day and drains into the drain tank. After 4 years 15*365*4, there will be 20 tons of makeup generated spillage in the drain tank.

    So, let me really speculate about the normal end to the 4 year can life. I would pump the 20 tons of spillage into the duplicate can(2) setting next to the can(1) directly above the dump tank (contains only 1/2 the fission products compared to the fuel-salt in the can). Then I would melt the fuse by operator command draining the can and filling the dump tank. Next pump 25 tons over to can2 and close down can1 and dump tank1 for 4 years to cool (still 20 tons in the drain tank1).

    Remember – these are all the musings of an old retired guy with lots of time on his hands.

  21. Good point, but the fuel still accumulates unwanted fp so when it is used the second time you will need to add increasing amounts of fissile to keep going.

  22. Changing the fuel with each can change also allows operating both cans in tandem for a 1 – 2 year transition period. Old unit does the preheating of the secondary salt and gradually tapers down to zero. This way you get more life out of each can and its fuel.

  23. rather good translation, only need to sort this one “After granted the licence from Bapeten”. and yes, it’s USD 1.25 billion.

  24. Martin has apparently hacked into ThorCon’s
    computer system, probably in collusion with the
    Russians. His description is right on. One
    small clarification. A drain in itself does
    not condemn the drain tank.

  25. I can neither confirm nor deny collusion with the Russians, but I have collected way more information from the same dubious source.

    Jack, you have made my day! May yours be satisfying too.

  26. Thanks Martin and Jack. Had not thought a out the amount os relatively fresh fuel spilled when adding make up fuel. Overall fuel economy is not great, only with Uranium recycling after 8y it is a bit better than once-through LWR. One of the disadvantages of the constant mixing is that you can’t remove the oldest fuel first, as you would in an LWR.
    The more I read about MSR, the better I like the IFR. Just compare the off gas system which for the IFR is — a plenum.

  27. I believe choosing one over the other is a false choice. If I had 10 billion dollars, I would fund 10 4th generation reactor companies. The hope is that one or several go big and keep the ice on Greenland.

  28. I got up this morning thinking about “increasing amounts” of fissile in the make-up daily additions. The concept of “net fissile” addition because we take out as much fuel-salt as we add. I get real confused trying to think about billions of fission product atoms so I am converting over to thinking about black and white marbles.
    A white marble is a fissionable atom. A black marble is a burned atom. There a 1,000 marbles in the jar. Each day 100 marbles turn black. We need to add white marbles until we have 1,000 white marbles in the jar again. That’s obviously not going to work.
    I have proven with this simple thought experiment that ThorCon can not work.

  29. @Matin Burkle

    What color are fertile atoms in your mental model? Though ThorCon reactors are not breeders, all reactors have a fair portion of conversion from fertile to fissile with a portion of the new fissile contributing to power output. Some of the fertile also fissions directly when the nucleus is hit by a fast neutron. The individual probability is low, but it is not an insignificant contributor to total power output.

  30. Good morning. I do my best thinking while asleep. ThorCon does not add 15 kg of makeup a day at startup.

    Rod: A white marble is a fissionable atom. A black marble is a burned atom. A wand is a control rod.

    The Story of Jack and the Magic Wand

    Jack starts with an old empty glass jar. He puts his magic wand in the jar and gradually adds 1000 white marbles while stiring. Nothing happens! Now, very slowly, Jack pulls the wand out. Watch the jar. There did you see it? One of the white balls turned black! Stop pulling the wand out, Jack! Oh, there’s another black ball and another. What happened? No balls are turning black. Jack pulls the wand out a little more. Good it’s working again. He pulls the wand out a little each day and each day 10 white balls turn black.

    On the day Jack’s wand is completely out of the jar, the magic stops. There are 900 white marbles left. Jack must makeup a new trick. Ah-ha. Jack tosses 100 new white marbles into the jar and 100 marbles spill out. Ten of the spilled marbles are black. Jack notices the as long as there are 900 white marbles in the jar, 10 will turn black each day.

    Rod: you can have a white ball appear out of thin air each day and change the numbers a bit to tell the story of self generating fuel. Obviously magic.

    Jack: I forgive you for leaving out the control rod explanation but then you didn’t have the black and white balls to tell the story:)

  31. The ThorCon cost are quite good but these costs do not include all the costs to build a functioning plant.
    1. ThorCon will not sell its product at cost. Probably closer to two billion (return on investment and profit).
    2. The cost of the primary loop (reactor vessel, primary heat exchanger, pump impeller, graphite, and can) is not included in the 1.2 because it is considered to be a consumable.
    3. The cost does not include regulator fees, grid upgrade costs, and training costs. These costs are very country dependent.

    Still looks to be cheaper than coal. If so, we will not need a world wide carbon tax to beat global warming!

  32. @Martin Burkle: What you are missing in your analogy is that the makep fuel has much higher fissile content than the startup fuel. The startup fuel is 20% LEU, but with 3 times as much thorium added. So the fissile content is 5% of heavy metal. The makeup fuel is just 20% LEU. So, by adding makeup fuel, they can make good of the lost fissile, even if they spill fissile at the same time. They can even gradually slightly increase the fissile percentage to make good for neutron poison fission products.

    So the neutronics make sense. This is in stark contrast with the original white paper from Transatomic power, which claimed they could use spent fuel actinide mix (fissile content about 1.5%) as startup AND as makeup fuel. This was clearly ridiculous, and I do not understand why people fell for it. 1.5% fissile is not enough for criticality in a light water reactor and ZrH is not a better moderator than light water.
    They also claimed significant fast fission in the unmoderated region, and the concept of a thermal core surrounded by a fast blanket is appealing. Sadly, with Li and F in the salt there is no such thing as an unmoderated region, as the salt also acts as a moderator.
    Moderation in the fuel also worsens the neutronics in the moderated core, as it makes the assembly less heterogenious. This will lead to more resonance absorbtion and increase the fissile content needed to maintain a chain reaction.
    Overblown claims are not good for credibility and hurt others like ThorCon and TE as well indirectly.
    The claims ThorCon makes on neutronics and fuel utilisation seem realistic to me. TE also seems to require a fissile content of about 5%.

  33. I think it’s just a question of trade-offs.

    The primary driver of the need to replace a ‘unit’ is the graphite, ThorCon seems to be intent on replacing just that and thus reducing the amount of good equipment you’d need to replace, Terrestrial wants to sync it with a full fuel refresh.

    There’s advantages and challenges for both that really need to be tested in real world usage before we have a clear idea how the cookie crumbles.

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