Catching Oklo — a rising star! 1

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  1. So that explains why the unit is so small; it is aimed at completely different markets from grid-scale electric generation.

    1. It’s aimed at getting power directly where it’s needed, without high transmission costs. Silicon Valley capital is coming from uptime, reliability, and long term costs for server warehouses. These warehouses are now amung the largest power buyers in the US. Buying even more power than aluminum foundries

      1. @Tucker – Thank you for visiting and making a comment about Oklo’s exciting product. (Is this your first comment here? I don’t think I’ve seen your name before.)

        I agree with your statement about the strategic investors from Silicon Valley that see advanced nuclear – including products like the Aurora – as a technology that they can directly use to improve their main business success.

        But “Silicon Valley” is also a financial center with characteristics and interests that are quite different from the traditional financial center in New York. Wall Street investment bankers are not habitually interested in new ventures that are creating the “next big thing” that will compete with the old, often very large thing that they have invested in.

        There is a very large pool of money in Silicon Valley that is focused on investing in clean tech that will help overcome the environmental harm created by many decades of burning fossil fuels. Many are keenly interested in technologies that will produce energy at least as reliably and abundantly as the fossil fuels that they will replace.

  2. “Oklo further recognized that the INL was storing waste from the EBR-II project and knew that this waste would be well suited to be the fuel for their reactor. They have secured an agreement with the INL to supply this waste and approval from the DOE to use it as fuel in their reactor.”

    If it can be bred into fissile fuel like U-238 or Th-232 can or is already fissile like U-235, Pu-239 or other fissile TRUs, is it really waste?

    There is a huge amount of fuel currently being stored as “waste” in the US, just waiting for reactors to be built that will burn it. Ed Pheil from Elysium estimates there is enough spent nuclear fuel to power their MCSFRs for 300 hundred years at current demand if they replaced ALL current US energy generation. It would be enough for over 1,000 years if it just replaced current US nuclear power generation.

    That’s before we even look at the 470,000 tons of depleted uranium now being stored as “waste” in the US as uranium hexafluoride that can also be bred into fissile plutonium or added directly to the fuel cycle of some fast reactors now being developed.

    The quicker we certify and start building these new designs the better.

    1. If it can be bred into fissile fuel like U-238 or Th-232 can or is already fissile like U-235, Pu-239 or other fissile TRUs, is it really waste?

      Rhetorical question, I know, but if it was too depleted to be used any further in the EBR-II then it counted as “waste” for that purpose.

      The quicker we certify and start building these new designs the better.

      I particularly like Elysium, as it’s so blame simple.  The main issues are salt compatibility with materials, particularly fission products.  I understand that the MSRE had issues with tellurium cracking, so that’s not just a theoretical consideration.

      There was a video posted on this on Reddit the other day:
      This data will be immensely useful to any efforts like Elysium and Moltex.

      1. The Elysium design is elegant. It’s basically an empty can. No graphite moderator core, and no frozen salt plugs in the pipes, if the pumps stop the reactor automatically drains the core salt into sub-critical storage and safes itself. With passive cooling from a heat pipe to deal with decay heat connected to the clean molten salt in the main tank all the components sit in. The salt itself is well understood chemically and safe, it’s table salt.

        The team doing the R&D for Elysium have over 300 man years crafting advanced reactor designs for the US Navy so they have a great deal of experience to draw on.

        They’re almost certainly going to run into issues like they did with the MSRE at ORNL. I think with the tellerium issue, the solution was to add niobium to the Hastelloy-N. They also had plating issues with some of the FP like the noble metals. They’ll have to come up with a mechanism to deal with that and something like the hydrogen parging used in the MSRE to remove some FPs like the Xe-135. That’s one of the nice things about molten salt reactors, you can process the fuel salt while the reactor runs. And add new fuel. A full up 1,200 MWe MCSFR will need about 4 tons of spent nuclear fuel added a year.

        Elysium is going to start with stainless steel for their first reactor design to avoid certification and licensing delays, so I’m not sure how that will impact the FP issue. Also the chemistry of the NaCl-KCl salt will be much different than the FLiBe used in the MSRE.

        It’s going to be really interesting to see where Elysium goes with their design.

        Or any of these groups, things are about to get very interesting in the nuclear power reactor field. Then in generation when all these reactors start coming online.

        1. It’s going to be really interesting to see where Elysium goes with their design.

          It seems very simple, which is what I like about it.  Nothing of significance in the reactor vessel, just a can.  The GENIUS of removing liquid water from the containment, by having only a superheater there.  I can only shake my head in appreciation.

          Or any of these groups, things are about to get very interesting in the nuclear power reactor field. Then in generation when all these reactors start coming online.

          IF any of them ever come online.  I’ve been waiting 3/4 of a lifetime for this, and I may still not see it.

          1. @Engineer-Poet

            Also corrosion stops being an issue when you remove all the water from the reactor, even when you’re running salt as your primary coolant and heat exchange.

            There have been a lot of factors keeping new reactor designs and nuclear power itself mostly sidelined for decades. Most of them revolving around the use of fossil fuels and how that has suppressed most competing energy development. That seems to be ending now.

        2. As far as sparging Elysium with helium, Xenon poisoning isn’t really ‘a thing’ in fast reactors – not saying they wouldn’t do it. The chloride reactors are quite fast; chlorine is a strong thermal absorber.

          I’d like to see less Elysium fan mail and more some detail on the INL/TP proposed chloride test assembly that recently got some funding –
          Wil this INL device be a “critical assembly” (i.e. zero power physics test)? If so, such a thing could actually get done quickly. If they were to keep the experiment solid state, I imagine much of the material science uncertainties fade away. Critical assemblies have always been of fundamental importance for benchmarking computational methods that would support operating reactors later built in the same vein.

          As for Oklo, I’m pretty sure 2MWe isn’t enough for a shopping mall, and nobody lives or works in the proposed regions where $200/MWh at the crank (prior to distribution) would supposedly be palatable. Taking a $4M lump of HALEU (market price prior to fabrication) to 1% burnup is not in the best interest of the climate; doing so in a $20M (guess?) plant is not in the best interest of investors.

          1. You can run this type of fast reactor with much higher fission product loads, I think it’s around 40%. The primary fuel cleanup with the Elysium MCSFR is predicted at between 40-80 years, so yes, removing FPs is a lot less of an issue than with a slow spectrum reactor. Some of the FPs are quite valuable, it will add to the economics of some of these design to be able to pull some of the FPs out as they run and sell them.

            How is describing what the team at Elysium Energy is actually designing “fan mail”. The head designer there Ed Pheil spent decades at Knolls Atomic Power Labs designing and building advanced reactors for the US Navy. His entire team from there came with him to Elysium.

            My comments are based on what experts with decades of experience actually building reactors are now developing as quickly as they can. A reactor designed from the start to be as economical, passively safe, certification process streamlined and low carbon producing as possible. While using spent nuclear fuel and plutonium as the main components in the fuel cycle.

            Coming from a US Navy family where this project comes from just adds to my confidence. I don’t really see how that is an issue when these guys deliver. Which is what they have been doing for decades already keeping us safe in a dangerous world.

            1. You think this thing has a future in Hawaii? Not sure how to respond to that claim… Oklo could power 500 non-AC homes.

              A diesel makes electricity for $300/MWh and costs $250k/MWe installed and can be installed next month with a township permit.

          2. @Michael

            The people who live in Alaskan villages that are not served by any grid and currently pay $250-$600 per MWh would be offended by your choice to call them “nobody”. As Ed Leaver has noted, you have also offended people in Hawai’i, Guam, and Puerto Rico.

            It’s also important to know that the Aurora – Oklo’s 1.5 MWe power house – is just the first in a large planned product line. They have chosen to follow a path similar to the one that enabled Tesla to succeed. They’ve identified a product for a market willing to pay a significant premium. That product is much simpler to produce than similar products in the market even though it might be costly to purchase the components with tiny order quantities.

            This product will help them build necessary support infrastructure, employee teams, quality assurance systems, and operating protocols. It will give them practice in dealing with the regulator – a process that also gives the regulator practice dealing with them and adjusting their requirements to be more appropriate than those used for very large light water reactors sold by vendors to customer utility companies.

            1. Puerto Rico has signed a new law that allows locally owned micro-grids up to 5 MW. I think that Oklo would be a wonderful fit. Hurricane resistant and able to get the small local grids (maybe 30 scattered around the island) up and running quickly after a disaster. With only 2,700,000 people these small reactors would stabilize an area greatly and provide for enough reliable power to enable at least small industry.

            2. The Philippines is another country with very high electricity prices and small grids. Oklo’s reactor would fit well on many of the 7,600 + islands. I have been on some of these that used to have only have a single 10HP gas generator for the whole island. I have also been where a drought reduced the level of a reservoir so low that they could not run the power turbines and we had rolling blackouts as a result. Areas like these will always have a difficult time building a grid connection to a large generation plant. Typhoons tend to damage infrastructure laid on the ocean floor. So while 200 + dollars / MWH seems high, I was personally paying between 24 to 34 cents / KWh at the meter back in the late 90’s while living in Manila. Things have improved since then but the costs are still very high averaging just over 20 cents / KWh.

    1. I’ve often thought about the analogy between computers and nuclear energy in terms of the way they have, and might develop.

      At the beginning, computers quickly scaled up from test machines to enormous, room filling devices aimed at only the largest users – government and corporate data crunchers. There were stringent security and export controls on large scale computing and various types of software.

      We should all know where they have evolved.

      Nuclear plants might follow a similar trajectory. Not as fast and probably nowhere near as far, but no analogy is completely predictive.

      1. The story of the Liberty Ships also offers inspiration. All the great passenger ships of the 1930s were gigantic, fast, elaborate, innovative, took forever to build and every one of them had cost billions of dollars. Then a great global crisis saw the mass production of 2700 Liberty Ships from 1941-45. The Liberty Ships were small, slow, simplified and very conservative. But they took only weeks to build and cost only $1 million apiece.

        The Climate Crisis is another great global crisis, with the industrialised nations under pressure to provide solutions for the entire world. For a start, state funding in the nuclear nations is needed to get production rates past the NOAKs to prices that the whole world can afford.

        1. It’s interesting that you hit on that analogy, because I’ve got a half-finished piece comparing Liberty ships to NuScale modules which has been sitting for years now.

        2. Then there’s ThorCon, which aims to put simplified nuclear power plants inside simplified ships to produce very cheap electricity for the grid.

    2. That article is behind a paywall so I couldn’t read it.

      There are good arguments for microgrids as they can create much greater energy security.

      Advances in applied “intelligence” in the grid has actually created new vulnerabilities. Like optimized grids where there is little overcapacity to respond to increased demand or decreased generation in a crisis. The “smart” grid itself is now vulnerable to cyber attack.

      Having discrete microgrids that can power limited and critical areas is probably a good thing. Doing it with technology that has almost limitless fuel and very low carbon emissions is a really good thing.

  3. “Oklo’s simple, safe and small reactor passively cools itself with a design that has already been well proven. They’ve based their modern implementation on the Experimental Breeder Reactor II (EBR-2), that ran for 30 years, providing a wealth of performance data that has helped the NRC regulator get comfortable with the design’s technical capabilities.”

    That’s all well and good. But will that NRC design review and certification experience scale the other direction e.g. to Natrium?

  4. Now that EBR-II is acknowledged in this space as the design
    prototype for Oklo Aurora, does Oklo Aurora have a public
    spec sheet like the other micros listed in the IAEA 2020
    catalog? Reference:

    The Oklo Aurora SMR book entry (p.297) shows the
    familiar artists rendering and a map of the INL site with
    parking lot.

    For comparison, the Westinghouse eVinci micro reactor
    entry (p.299) gives the usual technical parameters like the
    other entries in the SMR book (reactor type, coolant/moderator,
    power ratings, design overview, fuel cycle, design life, etc.)
    Evidently the eVinci design is thermal, heat-pipe cooled,
    and has a solid hydride moderator, which, If my understanding
    is correct, would enable a smaller core and fuel inventory than
    would be required in a fast neutron design.

    The eVinci appears to be feasible for use in Canada’s remote,
    off-grid communities. It is under review in USA as well. Reference:

    In both Oklo and eVinci cases, the actual safety, cost, and
    design life time scales remain to be seen. But it would be
    good to have data for apples-to-apples comparison sooner
    rather than later.

    1. @Chris Aoki

      Oklo’s competitors would also like to have the information you are seeking.

      It is a private company protecting private information as long as possible. At some point in the relatively near future, more information will be made public as a result of the NRC COL review process.

      But the delay helps build a head start.

    2. Yes, I wouldn’t put money on Aurora until we have heard about it from its engineers. The spin available on the web contains many errors of the sort I would attribute to overenthusiastic marketing.

      A mature design for the same market can be seen in Toshiba’s 4S reactor, proposed for Galena, Alaska. It did have a lot in common with the EBR2, including fast neutrons, metallic 20% fuel, and sodium coolant. Rod reviewed it some years ago on Atomic Insights –

  5. Saw lately a GenIV webinar, about heatpipe-cooled microreactors like the one for the planed moon station, the Westinghouse e-Vinci,.. Aurora seems to be in exact that spot.
    Good For ‘remote mining Operations, remote communities in Northern-Canada, Alaska,..
    Like a Diesel generator, but nuclear…
    Cool stuff, even the ‘concept Art’ looks like a ‘expensive toy for the rich’…;)))

  6. “What about the waste? What about the waste?,” the anti nuclear people continually wail.

    Oh we’ll just send it to the Oklo cabin somewhere in Idaho where it will be used to keep folks warm and keep their lights on.

    For once the nuke people must have got a PR guy when they showed the conceptual design for this thing.

    I’d like a cabin that looks like that myself, but by the lake not by the tumbleweeds and sage brush.

    Thanks for the article.

    Happy New Year!

    1. @Eino

      One of the changes that will define the coming 2nd Atomic Age is that there will be far more creativity in marketing. No longer will “the nuclear industry” be defined by giant multinational conglomerates that have many competing interests and no real motive for selling nuclear over other sources.

      Those players might still have a role in this rebirth, but they will have nimble, focused competitors. There are already new business models, a much wider range of sizes and shapes, and a greater variety of marketing approaches.

      My interest and excitement grow with every meeting we take with the leaders in the industry.

    2. Eino writes:

      “What about the waste? What about the waste?,”
      the anti nuclear people continually wail.

      There is some work going on now that addresses nuclear
      waste, for CANDU reactors, by producing a blended fuel
      mixture containing HALEU and Thorium. This seems like
      somewhat of a head-scratcher, given CANDU’s ability to
      run on unenriched fuel, which should be a cost advantage.

      See this article:

      “USA builds HALEU supply chain”
      Source: World Nuclear News 15 Dec 2021

      My understanding is that the blended (solid) fuel contributes just
      enough U235 issile material from HALEU to keep an otherwise
      Th232=>U233 driven chain reaction barely critical. Since the majority
      of the fertile U238 content of standard fuel is replaced by fertile Th232,
      the result is a net reduction in TransUranic isotopes (TRUs).

      The claimed net reduction in “Nuclear Waste” is 87% less, which
      if true, would be substantial.

      The project is a collaboration between Centrus Energy Corp., a US
      fuel enrichment company, and Clean Core Thorium Energy, a nuclear
      energy startup. Clean Core plans to test and qualify the blended fuel
      at INL during 2022 and expects to commercialise the fuel by late 2024.

      As the title of the article suggests, the creation of a supply chain for
      HALEU is at least as interesting as the outcome of the blended fuel

    1. @Chris Aoki

      You’re correct. We are working hard to learn more details about both the NRC decision and the next actions that will be taken. This post will need to be updated and linked to a new post providing as much information as is publicly releasable.

      1. Thanks Rod, we knew you would 🙂

        Dan Yurman had a brief summary yesterday over at Neutron Bytes — a bit more than WNN’s, but still not much.

        Meanwhile, Meredith Angwin points out ISO-NE posts a reasonably-realtime map of New England wholesale electricity rates. 23 cents/kWh as I write, Meredith tweeted 25 cents earlier this morning.

        Of course, New England is likely the last place in US to welcome new nuclear. Yet the concept persists.

  7. Hi there! Thanks for posting a link to my report on the NRC’s actions regarding Oklo’s application for a license. My post is necessarily a summary of the NRC’s actions. It’s a blog, not a engineering journal.

    However, for readers who want to take a deep dive into the NRC’s documentation, I provide multiple links to relevant source documents in NRC’s ADAMS online library.

    1. Thanks Dan — I intentionally minimized my link, and apologize for inadvertently also minimizing your own considerable effort. From which for me several items stood out:

      – NRC informed the company in a letter dated 01/06/22 [ML21307A108] that Oklo’s submissions in response to the RAIs (Requests for Additional Information) that, even with three rounds of RAIs, the NRC said it “finds that Oklo had not provided sufficient technical information to resolve previously identified deficiencies in the topical reports.”

      (Dan then provides three specific examples.)

      – Oklo told CNBC that the firm was not aware that the agency was planning to decide not to accept its application for a license. A spokesperson for Oklo said in an emailed statement that the firm is planning to resubmit its application.

      – CNBC reported that Caroline Cochran, one of the two principals at the firm, said she was hopeful the issues with the firm’s application for a license can be addressed. Cochran said she has been encouraged by some conversations she and the Oklo team have had with members of the NRC since the decision was made public.

      – The NRC said in its press statement that it has made the decision “without prejudice” and that Oklo “is free to submit a complete application in the future.”


      Well okay then. Perhaps it is just a failure to communicate. But at two years in, it strikes me as a pretty extended failure. As I’m no expert, rather than armchair this for now I’ll just allow that Oklo is new to this NRC thing, and look forward to Dan and Rod’s additional analysis.

      For those interested, as he notes above, Dan provides links for all of this — and more — on his blog.

      1. Short story: OKLO threw something at the wall, and it clanged. It didn’t stick.

        What part of “channeling an Apple-type vibe” didn’t work?

        Strike 2 for Millennials of MIT.

        1. Michael,

          Oklo is doing something hard. The NRC is doing something hard as well, under NEIMA’s new 36-month maximum review paradigm. Best as Rod and I can determine, this “denial without prejudice” is akin to stopping the clock. As soon as the team resubmits, they regroup with the NRC and proceed forward, with the banked experience of the prior 22 months of review still relevant and available. Millennials of MIT may have one out, but Oklo has only one strike and they can still hit a homerun.

          1. Oklo is just the latest example of breathtaking hubris bubbling-up from a well of outsiders convinced of their own exceptionalism. Oklo’s cartoonish COLA/FSAR efforts were quixotic, not valiant – not disruptive. I expected this application to die slowly over years; the rejection came more abruptly than even I expected.
            What has come of VSLIMM? What has come of Lightbridge? What has come of ThorCon? I have caught flack commenting on all of these slow failures ON THIS BLOG. These vlogger, fund-raising, conference-goers would do better for themselves working for operating companies or the major design bureaus (i.e. Westinghouse), but real jobs do not serve their egos. They want to be big Heroes – not little heroes that keep the lights on.
            There is no lack of creativity/vision in the industry. We don’t need disruption or Elon Musk. Nuclear power is a state affair. If the state is not behind it, it will not survive.
            Next to go the way of the dinosaurs: Kairos, Moltex, and half a dozen other fan favorites…

            1. @Michael Scarangellia

              I’m amused by your suggestion that people who want to see nuclear succeed – even in a place where the state is not the driving, organizing force – should go to work for Westinghouse. Isn’t Westinghouse the company that spent about 20 years designing an advanced passive reactor product (initially aiming at 600 MWe and thens scaled to 1140 MWe) for the global utility market? We are now past year 32 of the effort that began in 1990. How is that product going?

              The Atomic Energy Act has a path by which innovative effort like Oklo’s can proceed. It will take some continued effort, but the barriers that have been erected to prevent that path from being used are already falling.

              I wonder how a talented nuclear engineer like yourself decided to believe that the US nuclear enterprise as it is is doing just fine and does not need to be disrupted.

          2. If Valerie’s theory is correct, and it certainly has the ring of truth, then it is just another example of the bureaucracy thwarting legislative intent. The clock is not just stopped. It’s reset to zero.
            Lather, rinse, and repeat.

            1. Is that because the NRC’s requirements are actually nonsense or because these ego driven MIT dudes don’t want to spend the time and money? If they were to build this actual design – what in your mind is the worst possible accident that could happen and what would be the effect to people standing about 500 feet away?

              1. How about now? Don’t you think the “merger with AltC Acquisition Corporation with the hopes to raise $500M with the offering” is a 4th quarter Hail Mary pass (i.e. last ditch effort)?

                This one is dying, no matter how much hopium the tech bros inhale.

                How could Oklo’s business ever be worth $500M? A 1.2GWe PWR has about $600M revenue over an 18-month cycle.

  8. More news from WNN on an Oklo competitor, this time
    USNC (Ultra Safe Nuclear Corporation). Their MMR micro
    reactor product may be close to Oklo on the licensing front,
    but they’ve released a lot more information on technical specs
    on their web site and in the IAEA 2020 SMR book.

    Source: World Nuclear News, 08 Feb 2022
    Article: “Feasibility study for microreactor in Alaska”

    Source: International Atomic Energy Agency, 2020
    Title: Advances in Small Modular Reactor Technology Developments

    Source: Ultra Safe Nuclear Corporation

    I think the use of a molten-salt heat energy storage unit is
    interesting (cf., Natrium design used in Wyoming pilot plant)
    plus the enhanced TRISO fuel design with a Silicon Carbide
    matrix in place of the graphite usually found in HTGR pebble
    bed designs. Check it out.

  9. Yesterday’s WNN featured an encouraging report on a collaboration
    between Oklo and Argonne National Labs on commercializing the
    electrorefining technology from EBR-II. This would be vital to all kinds
    of nuclear reactor designs in reducing dependence on uranium mining
    as well as reducing output volume and radiotoxicity lifetime of material
    to be extracted from used fuel and disposed as “nuclear waste”.

    Source: World Nuclear News, 10 Feb 2022
    Article: Oklo, Argonne to commercialise advanced fuel recycling technology

    I also found the article’s artist rendering of the familiar Oklo Aurora
    building design to be surprisingly interesting. Depending on the
    reader/viewer’s perspective, it may remind them of the Wagnerian
    opera classic “Gotterdammerung” or “Twilight Of The Gods”, or the
    upcoming new book “The Beauty of Dusk: On Vision Lost And Found”
    by NYTimes OpEd writer Frank Bruni.

    Although I suspect that the former interpretation may be more
    popular with Internet trolls and anti-nuclear activists, I personally
    find the latter interpretation to be much more compelling and I look
    forward to the book’s publication on 01 Mar 2022.

  10. “stunningly gorgeous architectural design”
    Say you’re invested without saying you’re invested. The only description I’ve heard in the industry for this architectural design has been mockery.

    Praise be where it’s due though in pushing the NRC.

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