Talk:Clean and Environmentally Safe Advanced Reactor

Potential pseudophysics

This is an interisting concept. So... basically this is a epithermal/fast reactor that is cooled and moderated by steam? I am unclear as to how the heat transfer system and fuel are set up. Is the fuel pure U-238 metal in a steam environment, or is there cladding? Is the thermal-hydralic system refered to in the article present to capture waste heat like the material with a large heat capacity that is used in Sterling engines to capture heat? I think I interpreted enough of the original sources info, but it sounds a lot like an adveritsemnt for more funding... other sources for steam moderated power plants would be good to back this up. Lcolson 07:55, 12 February 2006 (UTC)

This looks like Pseudophysics. First, slowing down neutrons is a random process. A certain depth of moderator will slow down some neutrons all the way to thermal speed, leave some at the original velocity, and others at intermediate speeds. Second, there is no exactly right speed to split U-238. See the graph for "Neutron Cross-Sections for Fission in Uranium and Plutonium" in http://www.uic.com.au/uicphys.htm. U-238 has a broad curve starting above 1Mev, with increasing cross section with increasing energy. The faster the neutron, the higher probability of U-238 fissioning. I don't have an online source for this, but in "Megawatts and Megatons" by Garwin and Charpak, the capture cross section for U-238 goes down monotonically at all energies above 10⁴ ev. If U-238 could sustain a chain reaction, pure unmoderated U-238 would be best, but it is well known that it does not.

As for Carnot efficiency, it is limited by the highest temperatures that the materials can stand. To get 68%, the temperature would have to be 660 degrees C. If conventional fuel rods could tolerate this temperature in the presence of steam, then conventional plants would do this.

Therefore I am labeling this as Pseudophysics. For more wacky stuff, see [1]. pstudier 22:55, 1 March 2006 (UTC)

So the A James Clark School of Engineering at University of Maryland is harbouring cranks? I really don't that much about US schools - is this some questionable institution? If so and if this is nonsense I will be the first to put it up for deletion (even though I started the article) B.S. can baffle brains if it is served up right (in the shot term at least). --DV8 2XL 23:39, 1 March 2006 (UTC)

Don't know about harboring cranks, nor do I know anything about this university. Maybe he brings enough funding to justify keeping him. Here is another article from 1998 with a wacky scheme Putting Nuclear Waste to Work. If he wasn't a crack pot, then he would be very rich and famous with this invention. I think we should keep the article because he has had enough press coverage to be sufficiently notorious. If we delete, then the conspiracy nuts will scream that we are suppressing this invention. pstudier 00:13, 2 March 2006 (UTC)

I don't really see how any of your points show this to be pseudophysics. It's a little disturbing that I can't find much of anything published on this, but I rather trust the Economist to identify total cranks. And the University of Maryland is no research powerhouse (in my field at least), but it's certainly not going to keep around any pseudoscientists.

The description of how it works could be improved, but I definitely support removing the pseudophysics label unless anyone can provide some information pointing that way. — Laura Scudder ☎ 00:18, 2 March 2006 (UTC)

Let me simplify what I said. For fissioning U-238, the faster the neutron, the better. So unmoderated is better. It is well known that pure U-238 can not be used for either a reactor or a bomb, so this reactor concept can not work. Finally, he has been at this stuff since 1998 and has never published anything about it in a peer reviewed journal. pstudier 00:32, 2 March 2006 (UTC)

While the article certainly has other problems, you can definitely adjust the average speed of neutrons by adjusting the moderator's density as described. The mean path length before interaction for a given cross-section should be more or less constant, meaning that changing the density changes the number of moderator scattering events before interaction. I've removed the "pseudophysics" tag, for this reason and reasons cited by other editors above. While the article and linked web pages contain hyperbole, they don't appear to claim anything actually impossible (I'd tentatively attribute the Carnot efficiency concerns to something being garbled between the researchers and the reporters, as opposed to an impossible claim being stated by the researchers; this tends to happen a lot). --Christopher Thomas 05:31, 2 March 2006 (UTC)

Concerns about this article

While the article doesn't seem to describe anything technically impossible, I'm concerned that both the article and its references appear to use a very pro-nuclear tone, which I don't think is consistent with WP:NPOV. Also, as has been pointed out in the previous thread, there's a lack of links to bona fide peer-reviewed publications about this project and its predecessors, though with U of Maryland backing this it's not likely to be actual junk science. I strongly suggest that the article be rewritten to a short, neutral overview of what this reactor is, what its merits and drawbacks are, and a set of links to related concepts (fast breeders and so forth). It'll be about two months before I'm in a position to handle this myself, which is why I'm writing about it instead of going ahead and doing it. If it's still a problem in May, I'll take another look.--Christopher Thomas 05:36, 2 March 2006 (UTC)

I restored the pseudophysics category. From Nuclear fission:

Not all fissionable isotopes can sustain a chain reaction. For example, ²³⁸U, the most abundant form of uranium, is fissionable but not fissile: it undergoes induced fission when impacted by an energetic neutron with over 1 MeV of kinetic energy. But the neutrons produced by ²³⁸U fission are not, themselves, energetic enough to induce further fissions in ²³⁸U, so no chain reaction is possible with that isotope. Instead, bombarding ²³⁸U with slow neutrons causes it to absorb them (becoming ²³⁹U) and decay by beta emission to ²³⁹Pu. If this were not true, why would countries all over the world spend billions of dollars enriching uranium and prototyping breeder reactors if they could burn ²³⁸U? pstudier 22:02, 2 March 2006 (UTC)

This is a breeder reactor. I fully agree that the description as-given is somewhat mangled, and may include erroneous statements, but pseudoscience this is not. When run with steam at high density, it acts as a conventional thermal neutron reactor. When run with steam at low density, it acts as a gas-cooled fast breeder reactor. Most current and proposed FBRs are liquid-cooled, but gas-cooled ones have been proposed. I have doubts about a steam-based FBR being workable for practical reasons, but that doesn't make the project to study the idea pseudoscience. If you have a problem with specific claims in the article, how about editing the article, rather than dismissing the whole thing? Or backtracking sources to see where the claim came from? An article based on press releases reported by journalists _will_ contain serious technical problems, independent of the validity of the original source. --Christopher Thomas 22:19, 2 March 2006 (UTC)

From RESEARCH FRONTIERS AT THE UNIVERSITY OF MARYLAND, March 3 , 2003, Vol. 4, No. 1, available on the University of Maryland Website [2]:

“Right now,” he explains, “in every nuclear reactor in the world, there is a certain amount of nuclear fuel, which is mostly formed from a mixture of Uranium 238 and 235 moderated by water. U-235 is weapons-grade material, the material used to make bombs. Without U-235 or an equivalent isotope (e.g., plutonium 239) a conventional civilian reactor is unable to sustain chain reactions, and thereby produce power.

There are normally two types of these neutrons: prompt and delayed. Prompt neutrons are too fast, delayed neutrons are too slow. So in a nuclear reactor the prompt neutrons are slowed down by making them collide with water (the moderator). Therefore the thickness of water between the rods is designed to slow down the neutrons to the optimum speed for fissioning U-238. Unfortunately, the thickness of the water designed to slow down prompt neutrons and safely cool down the fuel rods is “lethal” to the less energetic delayed neutrons because, even if they manage to travel between the rods, the amount of water that they have to pass through slows them down so much that they have insufficient energy to fission U-238. Therefore, the thickness of the moderator (water) and its heat transfer characteristics are crucial parameters in the design of a nuclear reactor. But once the design of a reactor is completed, and the vessel containing the nuclear core is sealed, the ratio between water and fuel cannot be changed. This is true for nuclear reactor designs anywhere in the world.

So it is clear that this is not a breeder but that it supposedly fissions U-238. pstudier 23:32, 2 March 2006 (UTC)

Rewrite

Got rid of some of the POV phrasing for a start and integrated the skepicism in to the main body of text. --DV8 2XL 01:58, 3 March 2006 (UTC)

Thank you, it is quite an improvement. pstudier 02:46, 3 March 2006 (UTC)

Agreed, though finding reputable literature containing skeptical commentary would be even nicer (just so all is are dotted and ts crossed). Journal papers, rather than newsletters, from the proponents would be ideal, but you've already looked for those.--Christopher Thomas 06:30, 3 March 2006 (UTC)

Still tagged as pseudophysics

I'm having trouble seeing why this is still tagged as pseudophysics. Dr. Filippone thinks it'll work, many others don't, no exotic physics is proposed, the jury is out until they test it, and tests are planned (eventually) by a reputable institution. Isn't this how science is supposed to work? If the device fails, and Dr. Filippone makes claims that it's because mainstream science is wrong about something rather than that he couldn't get high enough neutron economy, then sure, but to my knowledge he hasn't made any such claims yet. The worst I've seen is an unfortunate tendency to hyperbole in the project web page.--Christopher Thomas 06:55, 3 March 2006 (UTC)

A chain reaction with U-238 is terribly exotic, and does not work for reasons that I have already given. Besides, he has been doing this stuff since 1998 [3], but apparently has never demonstrated a chain reaction nor published a paper in any journal. pstudier 07:15, 3 March 2006 (UTC)

As near as I can tell from the description you quoted and the project page, he's proposing that daughter products from induced fissioning of U238 produce enough neutrons (delayed neutrons) to keep fissioning U238, in a suitably designed reactor. I'm certainly _skeptical_ of this claim (I'd expect spent fuel rods to melt once removed from a normal reactor, for one thing), but I don't see how this can be ruled as pseudoscience unless someone actually demonstrates that the concept as-proposed can't possibly ever work, and he continues claiming that it does (paper demonstration would be fine, with good enough data on cross sections at various energies and species produced). Re. testing since 1998, I don't get the impression that Dr. Filippone has actually managed to test this under conditions that would conclusively prove him right or wrong (just much fooling with mock-ups of other parts of the system, and some testing with U of Maryland's experimental reactor, which is moderated by liquid water). His web page only lists very old publications. I've emailed him politely asking for CAESAR-related publication citations, and will post here when I get a response. If he hasn't gotten anything published, it does indeed bode ill for his credibility; we'll find out soon enough. --Christopher Thomas 07:33, 3 March 2006 (UTC)

Update: I've been extremely busy for the past few weeks, and will likely remain so. I didn't hear anything from Dr. Filippone regarding publications. I defer to your judgements regarding article content, as I'm not in a position to research it further at present. --Christopher Thomas 06:15, 22 March 2006 (UTC)

Some notes on Dr. Filippone

• From here (for what it's worth):[4]

"Claudio Filippone spent more than a year in a dispute with the University of Maryland over the patent status of his discovery, which would recycle used nuclear waste into fuel. "The inventor puts years into his work and the technology office gets a paycheck, no matter what," he says. "They never suffered for the technology but now they say that I owe them half of the work."

• This [5] shows that The College of Engineering of The University of Illinois Urbana-Champaign had him give a seminar on the topic last year.

• The neutronics, as described by the Press, are a crock - no question.

HOWEVER

Considering what I see in this paper by Filippone, [6]which deals with the thermodynamic aspects of this idea I have drawn the following tentative conclusions:

1. The design of the reactor would use a film of steam on the fuel rods, not an all gas moderator, and this makes a little more sense.
2. I suspect that he is not claiming to start or maintain fission in U-238, but use the increased neutron efficiency to do what CANDU's do right now with theirs and convert and burn more of the stuff through the standard reactor cycle of first converting it to Pu. The common Press being to lazy or stupid to describe it fully to their readers.
3. What isn't clear is that it is my understanding that it is not the lack of neutrons that stops CANDU fuel from burning but the build up of neutron poisons that renders the fuel exausted.

--DV8 2XL 15:08, 3 March 2006 (UTC)

Note that Dr. Filippone is not currently associated with the University of Maryland and that the document you reference is not a refereed paper but a proposal from 1998. As far as I can tell, the CAESAR concept has not been described in the regular scientific literature at all. I believe that this article violates the spirit of the Wikipedia:No_original_research rule and should be deleted. I see no reason that the CAESAR concept should not be mentioned in a longer nuclear reactor article though. Alison Chaiken 05:32, 5 March 2006 (UTC)

Alison, would you mind telling me how I have violated WP:NOR here? There is no novel interpretation or synthesis by me of this persons work; I have provided sources on the main article page that meet the terms of WP:V. I think that you might be confused about these policies and how they are applied here. --DV8 2XL 06:37, 5 March 2006 (UTC)

To pedantically quote the cited policy, "Original research is a term used on Wikipedia to refer to material added to articles by Wikipedia editors that has not been published already by a reputable source." We can argue that the CAESAR concept has been "published" on a web page, but I believe that's not the type of publication the policy intends. The links you have created point to popular articles written by journalists who don't have the ability to judge Filippone's contribution, not scientific publications by Filippone himself.

Perhaps I'm being too critical here. After all WP has articles on all kinds of inanities like television shows and rock songs. Nonetheless I take the physics articles personally and hope to hold them to a higher standard! Alison Chaiken 07:34, 5 March 2006 (UTC)

I can certainly appreciate your thinking Alison, and yes we could both keep each other in stiches for an hour or so trading URL's to web pages with some very bizarre ideas claiming to be physics, however I came across this in the Economist and then found the University of Maryland website, and these seemed to give some weight to the idea. So at worse I'm a victim of McLuhan's ditum that "the medium is the message." This is why I asked up thread if we should take this to AfD.

I reacted strongly to your insinuation because what I had written at the top of this section would indeed draw a righteous charge of OR had I put it in the main article space; but to the best of my knowledge this policy has not been in force on the discussion pages.--DV8 2XL 18:06, 5 March 2006 (UTC)

I have been aware of Filippone claims for quite some time. I think that this makes CAESAR noteworthy enough for an article that includes the reasons to be skeptical. Just like N ray and Polywater. pstudier 06:22, 5 March 2006 (UTC)

A physically impossible reactor

I am new to this sort of thing, but I must admit that I find myself fascinated at the discussion about whether or not this is "real" or "psuedo" or something else; yet no one seems to have taken the time to contact someone who knows anything about how a nuclear reactor works to see if there's any substance to the inventor's claims. My credentials: a doctorate in fission reactor engineering from MIT and 25+ years experience in the nuclear industry. My conclusion: the so-called "CAESAR" concept is bogus. To call it psuedophysics is being kind; the physics governing nuclear reactors show that nuclear chain reactions cannot be sustained in U-238, as Filippone claims. Moreover, his assertion that he can somehow "tune" delayed neutrons to cause U-238 to fission is false. Delayed neutrons are "born" with energies less than 1 MeV, and as pointed out in an earlier comment, U-238 has a 1-MeV fission threshold.

If you stick U-238 in a stream of neutrons with less than 1-MeV, all you get is conversion of the uranium to something else--primarily Pu-239. That's how a breeder reactor works. But it does not change the fact that you can't run a reactor off of U-238.

By the way, I have challenged Dr. Filippone on several occasions to submit his work to a reputable technical journal for peer review. His former colleagues at the University of Maryland have made the same request. He refuses to do so. Draw your own conclusions on that.