Talk:Sodium-cooled fast reactor

Is this supposed to be unbiased? I don't know enough to edit it, but it sounds remarkably like a sales pitch to me.

This is a suggested reactor design that isn't in operation at the moment, and the exact details of how it would be deployed are not determined yet, which is why the information about it is a bit limited. There will probably be more room for discussing the pros and cons of the SFR once actual designs are determined. Also, please sign your posts on the discussion pages by sticking four ~ at the end of them. This will automatically mark them with the date and time, as well as your account name (if you have one) making it easier to see who said what. Even if you don't have an account you should still stick four ~ at the end so we can see when a comment was posted. 88.90.197.94 17:13, 16 December 2006 (UTC)

It was by 131.128.197.49 at 15:42, 16 November 2006, and is the only contribution to date from that IP. Andrewa (talk) 16:49, 26 February 2019 (UTC)

First of all, "Sodium-cooled fast reactor" is a generic term and having it "hijacked" byt a particular research project is wrong as it is. This article should be retained for a 'general' description of this reactor type which would then link to articles on individual implementations - like the Russian production ones and the various European or US prototypes. Until the US-based project is split into its own article, this article will keep being a mess by its nature of being a marketing hijack.83.240.117.207 (talk) 12:33, 26 December 2014 (UTC)

All of this article seems to be about the US SFR project apart from the last line of the intro and the Reactors section. We need to split this article; eg. into Sodium-cooled fast reactor (project) and Sodium-cooled fast reactor (for the general category) ? - Rod57 (talk) 22:40, 27 September 2016 (UTC)

I've added a {{split}} to the intro. - Rod57 (talk) 14:02, 28 September 2016 (UTC)

or maybe the general type should just be a section in Liquid metal cooled reactor (and this article can be restricted to the specific US project) ? - Rod57 (talk) 14:18, 28 September 2016 (UTC)

Why the Expand tag? It looks like a good short article to me, despite the anonymous comments above. No details are given at Wikipedia:Requests for expansion#February either. Andrewa 16:33, 15 May 2007 (UTC)

I've rephrased the intro to conform to the WP:MOS and be a little less like a sales brochure, and removed the tag. Andrewa 16:43, 15 May 2007 (UTC)

The Design Goals section starts with these: "The operating temperature should not exceed the melting temperature of the fuel. It has been found that the melting point of a fuel called SFR-MOX (20% tranuranic oxides and 80% uranium oxide)." Clearly something is missing after the closing parenthesis, presumably the melting point of said fuel, as it stands now it doesn't make much sense. RealSunner (talk) 11:27, 26 June 2008 (UTC)

Certainly another unmentioned problematic aspect of sodium is that neutrons make it radioactive. Therefore the potential exists for sodium to come into contact with water and explode, and air and catch fire, releasing a radioactive plume. This is why two sodium loops are needed in the design. The second loop isolates the core sodium loop from the water/steam loop. Would the sodium in the secondary loop be made radioactive by contact with the first? How radioactive? How do you contain an explosion caused by contact between sodium and water say during an Earthquake or deliberately by terrorists that gain access to the plant? This seems to me to be the Achilles heal of this design and yet it not really discussed. 96.252.61.70 (talk) 17:18, 31 January 2011 (UTC)

If there were a break allowing sodium from the primary loop to enter the secondary, then yes, but by mixing rather than by contact. But Sodium-24 has a half-life of only 15 hours, so there'd be little lasting effect. You can see from the diagram that the only place water and sodium have to be close to each other is in the steam generator; there's not much water there and several places to stop the flow of sodium and water into it.

—WWoods (talk) 22:00, 31 January 2011 (UTC)

I appreciated your response, but it left several points unaddressed. The down side of a short half life is that it is very intensely radioactive, so if a large leak does occur it would be very dangerous, even if only briefly. I can believe that control systems could be designed to minimize contact between sodium and water if a leak occurred, but in a natural or man-made disaster, you would have water and radioactive sodium potentially mixing. The sodium cooled Monju plant in Japan had a leak that contacted air and very little water but was still hot enough to melt steel. Don't we have to be thinking of suddenly having the water and sodium loop mixed together if a large abrupt leak occurred? How would this be contained? —Preceding unsigned comment added by 96.252.61.70 (talk) 03:52, 16 February 2011 (UTC)

Sodium has a low neutron cross section, but yes some does absorb them and turn radioactive. One would have to find where the equilibrium is in a running reactor. How much Na24 there is. It seems that the Russians have plenty of experience with sodium fires, so maybe they know about this one. Gah4 (talk) 00:37, 13 January 2024 (UTC)

The Design Goals section may be going in the wrong direction. The section should be about "A sodium-cooled fast reactor design is chosen in order to acheive X, Y, and Z"; not "here are the features we want to design into our sodium-cooled fast reactor." Anyone agree? Abramov (talk) 23:24, 24 March 2014 (UTC)

The Russian Beloyarsk-4 BN-800 reactor has meanwhile reached criticality: http://www.nucnet.org/all-the-news/2014/06/25/russia-s-beloyarsk-4-ready-to-begin-nuclear-reaction Stepmose (talk) 13:11, 25 June 2014 (UTC)

After splitting the US project from the general type :

Could the Reactors section have the list converted to a table, with columns including construction start, first criticality ?, fuel type, pool/loop design, notes ? - Rod57 (talk) 21:57, 27 September 2016 (UTC)

Could we have a section giving the trade-offs between the pool and loop designs, eg on construction cost, operational cost, safety ... ? - Rod57 (talk) 21:57, 27 September 2016 (UTC)

Not sure what to suggest.

On the one hand, there is good content here that should be preserved, with its history of course.

On the other hand, the topic is ill-defined to the point that the article should not even exist. It's not about all sodium-cooled fast reactors, just about two very different Gen IV proposals (one with metallic fuel, one with oxide) that have no more in common than the BWR has with the RBMK. The title should probably be Gen IV LMFR or similar, that would at least match the topic, but it's still a rather strange topic. And with the topical nature of the topic(s), the article is chronically out of date... so, do we really want to spend the time updating it? Far better to have the material in the (many) other articles where it more properly belongs and is to some extent already duplicated.

And just to underline the problem, parts of the article are appalling... The operating temperature should not exceed the melting temperature of the fuel. Well, yes. We don't want the reactor core to meltdown during normal operation. Ummmm, am I missing something? Andrewa (talk) 23:51, 26 February 2019 (UTC)

7 years later and this article still has an identity crisis. Personally, I don't think there's any merit to keeping this article focused on the Gen IV proposal, mostly since the Gen IV proposal isn't substantially different from previous SFR designs. For example, both the Aurora nuclear reactor and the Natrium reactor are both very similar in design to the old EBR-II.

I feel like the best way to improve this article would be to move away from the Gen IV proposals entirely and just center it on the history, design, and current developments for all SFRs.

I've done my best to improve the Organic nuclear reactor article and I'm open to suggestions for how to fix this one. H2so4aq (talk) 22:38, 5 March 2026 (UTC)

@Andrewa: oh, cmon - tThe following sentence, Fuel-to-cladding chemical interaction (FCCI) has to be designed against., is at least as bad. But seriously, I think bad writing is obfuscating decision-making as to the scope of this article. Possible ideas we could pursue:

• Move to Generation IV sodium-cooled reactor, explicitly changing the scope of the article to exclude existing and historical sodium-cooled fast reactors
• Pare down and merge with Liquid metal cooled reactor
• Keep and rewrite to have a reasonable amount of focus on existing and historical sodium-cooled fast reactors, with less relative focus on future models.

Personally, I think the 2nd option (pare down and merge) is best, but I'd like to hear others' thoughts. VQuakr (talk) 02:43, 7 March 2019 (UTC)

Agree that the sentence you quote is equally appalling in this context. I note that the source cited is a highly technical paper. I would guess that whoever picked this factoid from it just grabbed it as being scary-sounding and has no idea whatsoever what it means. And this is typical of the politics surrounding the subject. But Wikipedia of course is not the place for me to promote my own pro-nuclear-power agenda either. I'm just confident that if we produce a good encyclopedia that is informative rather than misinformative it will help, see wp:creed. And there is a long way to go... I was once laughed out of a meeting of University students for challenging a speaker who had just assured them that plutonium had a longer half-life than uranium. The scary thing is that the overwhelming majority believed him, and we're talking here about uni students with an interest in the subject. (Email me if you'd like a link to my page on the story, here is not the place for it.) (sigh) And this is not the only subject that suffers... when I did semi-professional PA we used to say that you couldn't throw a hand grenade into a rock'n'roll audience without killing at least half a dozen sound experts. And the article from which I most often remove BS is drum kit. Not the drummers' fault either, my father (a metallurgist before he became a nuclear engineer) and I used to read my cymbal catalogs and laugh out loud. It will probably be generations before most drummers realise what lies we have been told!

And you seem to agree that something should be done about this particular article. I am somewhat relieved that someone else does!

Also agree that each of these three would address the problems. And I hope my latest effort might be a start towards one of them. Comments on it? Andrewa (talk) 07:43, 7 March 2019 (UTC)

I just had a look at Organic nuclear reactor and I'm almost tempted to suggest a bot to simply tag all nuclear power articles with Template:Expert needed. No (;-> not really... the template doco itself (rightly) discourages hit-and run. But see its talk. I'll get around to fixing it, or feel free to have a go... it's embarrassing, or is it only me that feels that way? Andrewa (talk) 09:31, 7 March 2019 (UTC)

The article says: and the hydrogen burns in contact with air. Well, it does if there is an ignition source. If it is close to the hot sodium, then there probably is, but otherwise it just mixes with air. It is light and floats away. But if there is a sodium leak near water, then yes it is hot enough to ignite hydrogen produced. Gah4 (talk) 00:40, 13 January 2024 (UTC)

It's been several years and this article still remains unfocused. Should this article remain focused on SFRs as a Gen IV proposal, or on all SFRs as a subset of liquid metal-cooled reactors? The article is currently focused on Gen IV SFRs, while the table of reactors lists every sodium-cooled fast reactor, even those before the Gen IV forum. I think there are a couple ways we could fix this:

1. Refocus the article toward only the Gen IV proposals, and rename to Sodium-cooled fast reactor (Generation IV proposal) or something similar
2. Refocus the article towards all SFRs
3. Move the article's content to liquid metal-cooled reactor and leave a redirect

I personally would support option 2 but am open to suggestions. My reasoning is that the Gen IV proposal didn't create the reactor type, it was just one of the reactor types selected by the Gen IV International Forum to have R&D focused on it. The article states that the initials SFR specifically refer to the Gen IV proposal, but doesn't provide a source to back this up. If this is true, I think it would be better to simply note that the acronym is a recent development rather than focus the entire article on it. H2so4aq (talk) 19:05, 23 April 2026 (UTC)

I can't seem to find anything discussing the initialism 'SFR', which is stated in the article to refer to sodium-cooled fast reactors specifically in the Gen IV Initiative context. At the same time, I've found many sources that talk about SFRs being existing technology, not only as part of the Gen IV initiative. Many of them describe previous reactors like EBR-I, Fermi 1, and Superphenix as SFRs. It seems it was initially added in 2019; @Andrewa: do you happen to remember the source used for this? H2so4aq (talk) 00:17, 28 May 2026 (UTC)

I don't remember. But I suggest you add the sources you have found. I personally recall hearing the term SFR long before the Generation IV International Forum ever existed, but of course I'm not a reliable source. I did work at the AAEC at the time, and while we did not have a fast reactor program, we did have fast reactor experts who attended conferences and visited and worked at fast reactor sites in the USA and the UK, witnessing for example the shooting of the heat exchanger of the British Prototype Fast Reactor with a high-powered rifle while the reactor was at full power for the last time. As pedicted, there was no explosion.

Those were interesting times.

These and other experts gave some fascinating lunchtime talks to the Research Establishment staff, which I attended. See here.

Similar games were played in the USA surrounding EBR2 but the Americans weren't ever as keen to share their findings... which led to some hilarious incidents. On at least one occasion they spent billions to reproduce what the Brits and we Aussies were doing at a fraction of the cost, all because it didn't occur to the Americans that there were other clever people in the world. For example when we built HIFAR the Americans would not allow the Brits to provide neutron collimators, so we just built our own, and accidentally built ones an order of magnitude better than the ones they refused us. It was some years before anyone realised the reason that some of our work was so far ahead of the international field.

I know of no book that has been written covering such things, and it's probably not going to be written. I can't write it as I am covered by the Official Secrets Act#Ausralia. But it doesn't only occur in matters nuclear. Years ago there was a hilarious article in the IBM Journal of Research and Development describing a theoretical treatment of the issues of an IMS/DC environment with a thousand similtaneous sessions. My employer of the time wrote back and confirmed their analysis, noting that we were regularly running 1200 sessions. IBM USA knew all about us, but apparently they had not told their research arm, and it didn't occur to these researchers to look for the biggest outside of the U S of A.

More interesting times. And they are not over. Andrewa (talk) 06:53, 28 May 2026 (UTC)

Certainly interesting times, and great stories. I'm definitely going to keep adding the sources I've found so far to the article, and I'll remove that sentence in the meantime unless I find a source for it. H2so4aq (talk) 20:33, 28 May 2026 (UTC)

I'm not quite sure which sentence you mean... is it perhaps an example of a the sky is blue statement? Andrewa (talk) 23:49, 29 May 2026 (UTC)

It was this one:

The initials SFR in particular refer to two Generation IV reactor proposals, one based on existing liquid metal cooled reactor (LMFR) technology using mixed oxide fuel (MOX), and one based on the metal-fueled integral fast reactor.

The sources I've found all describe the previous LMFRs like Fermi 1, Monju, etc. as SFRs, and I've been unable to find anything to back up this claim, so I removed the sentence for now. H2so4aq (talk) 06:23, 30 May 2026 (UTC)

Experimental Breeder Reactor II is described there as a Sodium-cooled fast reactor which article itself starts out A sodium-cooled fast reactor (SFR)... so if this usage of SFR can't be sourced we have quite a lot of work to do... I'm skeptical that it can't be sourced. Watch this space.

The interesting thing, which that sentence was I think expressing, is that EBR2 had a significantly different design to all other SFRs to date, in three important respects, and that it worked very well. My source for this is the book Plentiful Energy, I don't have my copy to hand but it was still in print last I checked. (And I should I think disclose my POV that construction of what I call EBR3 is long overdue.) Andrewa (talk) 01:08, 1 June 2026 (UTC)

I have a copy of Plentiful Energy, and used it to source significant parts of the article, but I don't think that it describes EBR-II explicitly as an SFR. It does, however, describe it as the first pool-type reactor, and that it was the first to demonstrate the integral, remote fuel fabrication and pyroprocessing technologies. Unfortunately, while they planned to build EBR-III to succeed it, the AEC's pivot to a loop-type oxide-fueled design seems to have killed off interest until the IFR program.

However, I have another source (Chapter 5: Sodium-cooled Fast Reactors (SFRs) of the Handbook of Generation IV Reactors) that states, "In the 1960s and 1970s, several experimental SFRs were built and operated successfully in the United States (Fermi-1, EBR-II, the Fast Flux Test Facility (FFTF)), ..." (I've found several others that say this) So I don't think we need to worry about whether the terms 'SFR' and 'sodium-cooled fast reactor' can be applied to these early reactors, even if they weren't described as such at the time. I still do want to track down when this term first came into use though. H2so4aq (talk) 07:03, 1 June 2026 (UTC)