Talk:Kairos Power

The "key indicator" for when a US SMR manufacturer can truly expect to go online is the company's NRC Final Design Submission. This submission shows a company can expect to go online within a decade. Previous SMR Final Design Submissions have taken up to 10 years to receive approvals. Kiros is advertising on this page that it is receiving several other NRC approvals that have nothing to do with "Final Design", which is false advertising to readers and suggests Kiros is in the final stages of NRC approval. They are not and have not even started the true review process yet. Whenever an SMR designer/manufacturer wants to include NRC approval information in their bio, they should ALWAYS include if they have submitted for "Final Design" with the NRC and when. If they have not submitted yet, this must be included. This tells the reader how many years the company must wait before going online with their reactor. Previous SMR designs have waited an average of 10 years for Final Design approval. Kairos has yet to submit a proposal for "Final Design" with the NRC. For some reason, this information is being removed. Ludviggy (talk) 01:31, 9 March 2026 (UTC)

Sorry for the long reply, but I am still not sure what you mean by "Final Design Submission", as the NRC has no such thing. Further, I don't know where you're getting the 10-year average timeline from for NRC approvals.

There are two ways of building a reactor through the NRC. These are detailed in Chapter 10 of the Code of Federal Regulations (10 CFR). The first, and most common, is through 10 CFR Part 50. First, a licensee (nuclear/SMR company) submits an application for a construction permit. This includes a preliminary design safety analysis report (PDSAR) and a preliminary environmental impact statement, both of which are reviewed and approved by the NRC for the permit to be issued. This allows construction of a nuclear power plant to begin. Second, the licensee applies for an operating permit to allow nuclear fuel to be loaded and the reactor powered on. This application includes the final design safety analysis report and final environmental impact statement, which are then reviewed and approved.

The second way, which I believe you are referring to, is through 10 CFR Part 52. This method was created following the Three Mile Island accident, and separates the site-specific license component from the design review component. This process was intended to allow a nuclear reactor or plant design to be reused without further review of its technical details. Part 52 involves a licensee applying for a Combined License, which is a combination of the construction and operating permits.

A licensee, along with or separately from a Combined License application, can apply for a Standard Design Approval (SDA) and/or a Standard Design Certification (SDC) [sometimes referred to as Final Design Approval and Final Design Certification], which are essentially standard NRC approvals for a nuclear reactor (SDA) and full power plant design (SDC). These are intended to make the approval process faster for reactor developers, and is especially significant for SMR developers who intend to make many units of the exact same reactor. However, neither are required to build an SMR or any other nuclear plant, and indeed there are advantages to pursuing a license through Part 50 instead of Part 52.

Multiple nuclear companies have received SDAs or SDCs: Westinghouse, which received one for their AP1000 reactor and power plant in 2006, and NuScale, which received one SDA in 2020 for their US600 12 x 50MWe power plant (VOYGR-12), and another in 2025 for their US460 6 x 77MWe power plant (VOYGR-6). Korea Electric Power Corporation received one in 2018 for their APR1400 design, and General Electric received two for their ABWR and ESBWR designs. While the ABWR and ESBWR applications took around 10 years each to complete, the APR1400 approval took only 4 years, same with AP1000. The NuScale design approvals took around 2 years each.

I am not sure where you are getting the timeline that a design approval takes around 10 years. You are correct that they have taken up to 10 years to complete, but the average completion time is much lower. Further, only two SMR approvals have been issued and they both took only 2-3 years.

Further, neither the Part 50 construction/operation permits, nor the Part 52 combined license, SDA, or SDC approvals are the "true" review process. As mentioned previously, there are two different ways of licensing a nuclear plant, and they both are useable for SMRs. Indeed, multiple SMR companies are pursuing licenses through the Part 50 process (TerraPower [debatable whether you consider Natrium as an SMR or not], Kairos, X-Energy, etc.) rather than through Part 52 like NuScale. In addition, having operating experience from an actual reactor, even one constructed through Part 50 not Part 52, makes getting a standard approval much faster. In comparison, the AP1000 standard design approval, which had never been constructed before, had to be changed multiple times during the construction process of the Vogtle Electric Generating Plant Units 3 & 4 (its first units). Having to amend the license multiple times drove up the construction cost and time, while a Part 50 license would have not required changing the construction permit for minor design changes.

As to your point about the Kairos Power page: It isn't misleading to the reader that they are are receiving several other NRC approvals - they are receiving NRC approvals to build two nuclear reactors (Hermes and Hermes-2) licensed via Part 50. They have currently received their construction permits to build both plants. This is not "false advertising"; this is the approval process.

Whether you think it would be better for Kairos, as an SMR developer, to pursue an SDA and SDC through Part 52 and apply for a combined license is irrelevant because they are both legitimate NRC approvals.

As to the importance of the fact that many SMR designs are proposed and therefore essentially speculative, I agree with you that it is really important to say what their licensing status is. Many SMR developers and designs have been proposed and relatively few of them (in the US) have even submitted for a construction permit or SDA. But not submitting a Part 52 SDA application instead of a Part 50 application does not mean that a company must wait 10 years for their reactor to come online, nor does receiving one mean their design will be built quickly.

Please let me know your thoughts. H2so4aq (talk) 18:56, 9 March 2026 (UTC)

More information about "Standard Design Approvals": https://www.nrc.gov/reactors/new-reactors/advanced/who-were-working-with/past-license-activities/nuscale/documents

Note: The approval is also referred to as an "SDA-600".

The "final" SDA-600 submission is when the NRC waves its green flag and begins the typical 10 year research/approval/rejection process on a manufacturer's SMR. Until a final version of the SDA-600 is submitted, a manufacturer should acknowledge it is more than a decade, at the very least, from going online with a commercially operational product. All previous attempts by the NRC to speed this process up through alternative methods have failed to meet all shortened deadlines. Kairos should be honest and inform prospective clients of these facts and also expect the addition of a totally new fuel source to lengthen the review process further. Ludviggy (talk) 21:02, 10 March 2026 (UTC)

Thank you for your reply. First of all, that approval is not an SDA-600, it is the SDA-600, which simply refers to the SDA (Standard Design Approval) for the NuScale US600 power plant (aka VOYGR-12), which according to the page you linked is called the "Standard Design Approval US600", or SDA-600 for short.

As I said before, an SDA is not the only method of building a commercial nuclear power plant, even an SMR design, and I am still unaware of where you are getting the timeline that until an SDA is issued, it is at least a decade before a commercial power plant can come online. An SMR design, even one that is not certified through an SDA or a Standard Design Certification (SDC), can still be constructed commercially via a Part 50 license, which is what TerraPower, Kairos, and X-energy (X-energy's Part 50 construction permit for the Long Mott plant is under review) are doing.

When you say that the SDA is the "green flag" for the NRC to begin their 10-year approval process, what exactly are you referring to here? Are you talking about the issuance of a Combined License based on an SDA? Licenses, either a Part 50 Construction Permit + Operation Permit or a Part 52 Combined License, do not require an SDA in order to be obtained, although it would make the review process faster. Regardless, I am still confused by whether the 10-year timeline you mention refers to the SDA or issuing the actual license. Could you please be more specific as to what approval you are referring to?

Second, you stated that "All previous attempts by the NRC to speed this process up through alternative methods have failed to meet all shortened deadlines". This is simply not true; the NRC has been speeding up its approvals significantly: the TerraPower Kemmerer Unit 1 construction permit was issued in just under 2 years, and was 9 months ahead of schedule, while the Kairos Hermes 2 construction permit was also issued in under 2 years, and was 4 months ahead of schedule (source). The linked article also refers to the NRC's Licensing Modernization Project, which has been going on since 2020. The fact that a reliable source indicates that the NRC's attempt to speed this process up is in fact yielding significant results is in direct contrast to what you are arguing here.

You also said that "Kairos should be honest and inform prospective clients of these facts and also expect the addition of a totally new fuel source to lengthen the review process further." The company has already signed a power purchase agreement with Google to buy the power generated by their Hermes 2 reactors, which have already been approved for construction by the NRC. It seems to me that "these facts" that you are alluding to are your own speculation on the NRC's timeframe here.

The company says it is targeting 2031 for operation of the reactors, and we don't know whether that will happen or if they will miss the target date. But in the absence of reliable sources that argue that they will likely miss this timeframe and cite a specific reason for why the author believes they will, it is unreasonable to add our personal speculation to the page about this company on the grounds that there might be a delay in the future.

Finally, what is the new fuel source that you are talking about? Is it HALEU? TRISO? Pebble fuel? Neither of those are new fuel types, and the NRC has not shown any indication that these are going to cause significant delays given the approval times for the CPs for Kemmerer (KU1) and Hermes 2. The POWER Magazine article I linked above states that for Kemmerer Unit 1, "the NRC said several features of the KU1 design are expected to enhance safety compared with earlier systems. These include the use of high-assay low-enriched uranium (HALEU) fuel with favorable neutronics characteristics...". Based on this response from the NRC's staff, I don't find it reasonable to assume that the use of HALEU would cause significant delay in licensing for either KU1 or Hermes 2. Again, personal speculation on what might cause a delay in licensing is not appropriate for Wikipedia.

There have been several articles where authors claim that HALEU fuel may cause delays in the start of operation of several SMR designs, simply because the fuel is difficult to procure in the United States. In my eyes, this is a reasonable thing to state on a company's Wikipedia page: that there are groups who argue that they will likely suffer a delay on their project's operation because of a lack of fuel. But this has nothing to do with the NRC's licensing process, and would be the same whether a company has both an SDA and Combined License or a Part 50 construction permit. H2so4aq (talk) 07:17, 11 March 2026 (UTC)

Is TRISO NRC approved? If not, it's new. My speculation of the timeline is based on previous approvals. What is your speculation it will take less than 10 years from the "final" SDA-600 submittal based on? Nothing. There is no history of it taking less and attempts to shorten the NRC review process have repeatedly failed.Ludviggy (talk) 01:07, 12 March 2026 (UTC)

I was invited to this conversation by H2so4aq's post on my talk page here And everything nuclear is of interest to me.

The easy and efficient way to solve disputes like this are to follow Wikipedia's policies: WP:NOR and WP:SYNTH. Instead of arguing based on what editors (who may be very knowledgeable) either know or believe they know, we say ONLY WHAT SOURCES SAY.

That means in this case, this edit makes claims not in the two listed sources, neither of which gives average OR expected approval timelines. The second source does say: "Kairos will file a separate application for a Hermes operating license from the NRC in the future.", so we CAN either state that, or copy verbatim because to my knowledge, works of the federal government are not copyrightable. *IF* a source talks about average approval timelines, AND that source talks about it in respect to Kairos' proposals, than we could include that type of info.

Lastly, to H2so4aq: please make more concise arguments based on policy; be mindful of WP:TLDR; though I did read your posts. ---Avatar317^(talk) 05:50, 12 March 2026 (UTC)

That makes sense. Thank you for your feedback as well; I'll try to be more concise and keep WP:TLDR in mind in the future. H2so4aq (talk) 23:28, 12 March 2026 (UTC)

Agreed. I do believe my original posting in this article will be allowed under your decision, which is: "As of March 2026, Kairos had yet to submit a final design approval (SDA-600) for its reactor. Previous NRC approvals for SMRs have taken up to 10 years to receive final design approval."Ludviggy (talk) 05:00, 13 March 2026 (UTC)

Where in either source is that wording supported? - Please provide quotes. ---Avatar317^(talk) 05:08, 13 March 2026 (UTC)

The presentation of many NRC approvals in this article is, in fact, a suggested timeline and an obvious "suggestion" that Kairos is close to being NRC approved to go online. As you should now know, these NRC approvals mean nothing. The MOST important NRC approval is the SDA-600. Just so you know, this is an issue throughout many industries. Organizations will commonly announce new construction permitting and park a bulldozer on the project site, sometimes for 10 years until the critical permitting is approved. Why do they do this? False advertising. Construction permitting is used by marketing to convince investors through news outlets an organization is making progress, accomplishing its true goal of reaching completion (think Vaporwear). When, in fact, it is nowhere near that perceived goal and often is not fully permitted to achieve full completion. If you include any NRC approval information in an SMR article, you should ALWAYS include IF an SDA-600 has been submitted and when. This is the only NRC approval that provides any kind of predictable timeline. Previous timelines for other competitors are also very useful in helping the reader understand what is more than likely ahead. Ludviggy (talk) 19:52, 14 March 2026 (UTC)

I understand what you're saying, and you are correct; corporate press releases claiming that they will produce/build/supply X,000 widgets in Y years time are just that: claims, and should be stated as such, and we shouldn't use press releases as sources for statements in Wikipedia at all.

There is no Wikipedia policy supporting your OPINION: If you include any NRC approval information in an SMR article, you should ALWAYS include IF an SDA-600 has been submitted and when. - we just need to find the WP:BESTSOURCES and paraphrase/summarize them.

As I said above, "The second source does say: "Kairos will file a separate application for a Hermes operating license from the NRC in the future.", so we CAN either state that,..." - we could state "As of <date of source>, Kairos has not yet submitted an application for their operating license."

But you still didn't answer my question above: "Where in either source is that wording supported - Please provide quotes." - from what I read, neither source mentions (SDA-600) or a 10 year timeline. ---Avatar317^(talk) 00:28, 17 March 2026 (UTC)

https://www.nrc.gov/reactors/new-reactors/advanced/who-were-working-with/past-license-activities/nuscale/documents

"The duration of this SDA is 15 years in accordance with 10 CFR 52.147, “Duration of design approval.” If the NuScale design is subsequently certified, then this SDA will be updated, as needed, to conform to any changes resulting from the DC certification rulemaking."

Operation license vs. SDA-600: An SDA is submitted at the start of the NRC "plant" review process. This is why it is such a good determination for how long a designer/manufacturer will need to wait before receiving an "operation" license. "SDA-600" has value to the reader now. 10 years is, obviously, less than this estimate. 15 years was the estimated timeline the NRC estimated for existing approved NRC technology (PWR). Kairos Power's SMR plant/fuel (MSR) has never been commercially approved for use in the US. `Ludviggy (talk) 20:10, 17 March 2026 (UTC)

That source does not say anything about estimated timelines, nor does it say that an SDA is required to license a reactor.

The "duration" of an SDA is the length of time during which a plant designer can submit an application referencing it, not the estimated timeline it takes to build the plant. This is stated in 10 CFR Part 52 § 52.147 Duration of design approval: "A standard design approval issued under this subpart is valid for 15 years from the date of issuance and may not be renewed."

The SDA duration is also not design-specific, it is set by the regulation to always be 15 years, nor does 10 CFR Part 52 (linked above) contain any reference to PWR technology.

Please also provide a source that states that an SDA is required to receive an NRC operating license. I have found multiple sources that state the process and none of them even imply an SDA is a requirement to license a reactor: . Quoting the second source, from the American Bar Association:

The NRC provides two parallel processes for the licensing of nuclear reactors: a “combined license” (COL) under 10 C.F.R. part 52, and a “two-step” process under 10 C.F.R. part 50. ... The regulations in 10 C.F.R. part 52 also allow the NRC staff to approve reactor designs and for the NRC to codify certified designs by rulemaking.

The first source, a slide deck from Idaho National Laboratory, shows on slide 7 the Part 52 approval process, illustrating that the SDA is optional. Slide 14 states explicitly that a Part 52 Combined License, "May reference a Design Certification and/or ESP" [Early Site Permit]. H2so4aq (talk) 23:08, 17 March 2026 (UTC)

It's probably worth mentioning at this point that the meaningless NRC approvals provided in this article are for Kairos Hermes 1 or Hermes 2 reactors. This is not an indication of when Kairos Power "genuinely" expects to go online with a commercial SMR. The Hermes 1 and Hermes 2 are only "test" reactors. It would be clearer if this was more clearly pointed out in the history. I'll bet a lot of readers believe Kairos Power was going to have an NRC-approved commercial SMR reactor ready for market by 2030 https://www.nrc.gov/reactors/non-power/new-facility-licensing/hermes2-kairos. Based on this alone, it could also be said that "As of March 2026, Kairos Power had only applied for NRC test reactor approval. Non-test SMRs take around 10 years for approval, once a final design is submitted." Ludviggy (talk) 23:03, 18 March 2026 (UTC)