Talk:Nuclear fission product

My dim recollection is that there's quite a bit more Iodine & Caesium than the others, but I'll try and check. Linuxlad 11:16, 30 Nov 2004 (UTC)

Someone has done a lot of work on this, which is good; but they haven't paragraphed or sign-posted it up well enough IMHO. The result is, I suggest, a very slabby article that few wanting to quickly learn about the subject are going to find approachable. Linuxlad 11:09, 5 November 2005 (UTC)
 * So, go to work DV8 2XL 15:38, 5 November 2005 (UTC)
 * I always give the relevant author first refusal :-) Linuxlad

Dear Linuxlad,

I see your point that the article has lots of info but is not subdivided, if I subdivide it a little will that make it OK ? Cadmium 13:40, 19 November 2005 (UTC)

About biological half life, I think that a recent edit has made the page misleading. I think that it is important to know the difference between biological and physical halflife. I will write a new page on biological half life to make this clear.Cadmium 17:33, 20 November 2005 (UTC)

I've tried to help clarify and straighten things out, but it seems I spent most of my time in the 'countermeasures' section which I'm not even sure belongs in this article (not going to take any action in that regard, though). I'll try to get back here when I have more time; in case I can't, I'll justify the cleanup tag since its poster did not. If these things were addressed (easier said than done; probably best to rewrite, especially considering the, er, less than enthusiastic use of citations regarding hard data and asserted standard practices), even if a shorter article with less information were the result, the article would be substantially improved. BryanHolland 07:42, 6 July 2006 (UTC)
 * information is duplicated within the article
 * Chernobyl, pharmacokinetics, and fission in general are addressed elsewhere in Wikipedia
 * While to some degree the broad scope of the article might be helpful, the general disorganization leads to a situation where:
 * the answer to the immediate question (What are the products of nuclear fission?) is obscured by topics not strictly relevant.

Rewrite
Alright... I've undertaken a rewrite at Fission product/Rewrite. If anyone is inclined to contribute, feel free, but it doesn't seem that there's a lot of activity here. BryanHolland 19:45, 6 July 2006 (UTC)

XD That's the funniest thing I'v ever seen on Wp:
 * http://en.wikipedia.org/w/index.php?title=Fission_product&oldid=115851024
 * http://en.wikipedia.org/w/index.php?title=Fission_product&direction=next&oldid=115851024
 * -lysdexia 14:42, 12 April 2007 (UTC)

Sum of fission product atomic masses
I'm not a physics student but I'm pretty sure this statement is wrong: "The sum of the atomic weight of the two atoms produced by the fission of one atom is always less than the atomic weight of the original atom. This is because some of the mass is lost as free neutrons and large amounts of energy." —Preceding unsigned comment added by 122.107.181.199 (talk) 05:30, 28 December 2007 (UTC)
 * The statement seems OK, although I have not specifically checked any data. Whether or not unbound neutrons are produced, a small amount of atomic mass is converted into a [relatively] large amount of energy in this nuclear reaction.  In nuclear reactions, there can be mass/energy interconversion.  Why do you think it's wrong?  H Padleckas (talk) 18:53, 29 December 2007 (UTC)
 * I concur - the statement is correct. But it is oddly positioned here without context.  PJG 04:42, 10 January 2008 (UTC)

The statement is correct because of this reaction: 235U + 1N => 236U =>  144Ba   +  89K   +  3 1N

All 3 add up to 236 but counting just the atoms final product adds up to only 233.Jkbell (talk) 04:34, 28 May 2017 (UTC) JKBell http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/U235chn.html

Update
The previous definition was essentially circular - "A fission product is a product of fission." It was also so short it was easy to miss. So I've provided a more descriptive definition.

I also updated the next section (and retitled it) to focus on the physics. I want to improve this further with more discussion on formation, including a specific example and introduction to the concept of Yield, but need to do a little leg work. Stuff that was not direcly relevant to fission product physics or is covered later (examples of fission products are nicely given in tables) has been deleted. PJG 04:42, 10 January 2008 (UTC)


 * Looks like a good start. I have also felt much of the article could use rewriting but the amount has been daunting. --JWB (talk) 00:31, 11 January 2008 (UTC)

I'm considering if the "Chemical nature of fission products" section should be deleted. FP chemistry is simply that of the element, and should be discussed under that element, or perhaps under the particular isotope if there is some important radioisotope chemistry (eg. Iodine would be discussed in 'Iodine' or possibly 'Iodine-131'). Putting chemistry in this article would duplicate information properly in other articles. Plus presently we really don't have any info on chemistry - the chart of electronegativity may be correct but is only a very small part of chemistry, and is sitting here without any discussion or context. Comments? PJG 22:59, 27 January 2008 (UTC) —Preceding unsigned comment added by Giersp (talk • contribs)

I have now cleaned up the discussion on Yield. (Para on FP decay from nuclear weapons moved to later.) Two issues:  First, I haven't figured out how to arrange the flow of text around the two Table templates, so it currently does not look nice. Second, the yield figure is at least unusual and I'd like to verify. Yield curves are smooth when expressed by mass number (as in the reference link). If they become very discontinuous after 1 year and expressed by element as per this figure, then that linkage should be explained.PJG 01:50, 28 January 2008 (UTC) —Preceding unsigned comment added by Giersp (talk • contribs)


 * I've checked against some burnup results I have and get a quite similar yield graph when organized by element, so have verified this figure. It would be great to have the classical two-hump figure by mass number available as well, if someone is feeling ambitious!  (I'm not sure why the SineBot keeps signing for me...) PJG 03:10, 29 January 2008 (UTC)  —Preceding unsigned comment added by Giersp (talk • contribs)


 * I have some yield data for U-235, Pu-239, and U-233 with thermal neutrons in a spreadsheet, and produced a couple of graphs using Excel's charting but am not totally satisfied with the formatting. I'm also considering using the data in an SVG graph which might offer more flexibility in format if one is willing to hand-edit SVG code, as well as being the officially preferred Wikipedia format these days. I've also wondered whether a log scale graph would better show the data for the low-yield fission products. --JWB (talk) 05:30, 29 January 2008 (UTC)


 * Sounds good - nice also to be able to illustrate eg U/Pu difference. However, I am unfamiliar with SVG format so can't help there. WRT log-scale, ref 2 in the article is to a web page with a log-scale graph.  I think this looks good and is also how it is presented in my textbooks.99.230.71.169 (talk) 20:56, 29 January 2008 (UTC)

Claim that FPs less active than "original ore" in several hundred years
I've seen different figures claimed: 200, 300, 400 years.

I'm pretty sure the claim is based not on U-235 (as in the edit I just reverted for discussion) but on all the U-238 in the uranium, including depleted uranium removed during enrichment in the LWR case, and all its decay products.

I'm not a proponent of the claim or of describing FP radioactivity in that particular simplified way, and have tried to phrase the article so that it is not endorsing the claim, but this statement is so commonly seen that it needs to be mentioned and discussed. Ideally there is a more detailed analysis of it in a reputable source somewhere that we can reference.

In my opinion the most misleading thing about the claim is that it doesn't tell the reader that LLFPs exist at all, and I've tried to remedy this by including information on LLFPs in this and other articles, so that readers are aware and can research more if they wish. On the other hand, the most significant truth contained in the claim is that there is a gap in FP halflives between 100 and 200,000 years, and I've tried to also state this specifically in this and other articles. --JWB (talk) 18:35, 7 September 2009 (UTC)

Chemical hazards?
A layman's question: given that fission produces such a colorful mixture of chemical elements and that the core is also pretty hot - isn't there a chemical hazard as well? Can't the stuff form corrosive compounds that eat away the housing, the control rods, and pretty much everything else in sight? Also, some of the stuff produced (such as Xenon) is gaseous - where does that gas go? Can't it burst stuff? Please add some info on this if you have it. -- 92.229.158.233 (talk) 07:09, 26 April 2010 (UTC)

iodine
The long essay on perchlorate vs. potassium iodide is beyond the scope of this article. I vote for abridgement. It's a laborious read.

173.25.54.191 (talk) 14:04, 20 May 2013 (UTC)

Questionable Half-Lives Versus Beta Decay Rates for Strontium Isotopes
I found questionable agreement between the half-lives and the beta decay rate comparisons in the second through fourth sentences of the fourth paragraph. On July 30, 2015 it states: ''For instance, strontium-90, strontium-89 and strontium-94 are all fission products, they are produced in similar quantities, and each nucleus decays by shooting off one beta particle (electron). But Sr-90 has a 30-year half-life, Sr-89 a 50.5-day half-life, and Sr-94 a 75-second half-life. When freshly created, Sr-89 will spray beta particles 10,600 times faster than Sr-90, and Sr-94 will do so 915 million times faster.''

The ratio of 30 years to 50.5 days is 30 x 365 / 50.5 = ~217, not 10,600. Also, the ratio of 30 years to 75 seconds is 30 x 365 x 24 x 60 x 60 / 75 = ~12,600,000, not 915 million. Did I miss something?BillinSanDiego (talk) 20:31, 30 July 2015 (UTC)

independent vs. cumulative
Should we discuss somewhere, here, fission product yield, or both, the difference from independent and cumulative yield? IAEA seems to have some good discussion about it, which is where most of the tables now in fission product yield come from. Gah4 (talk) 10:09, 16 August 2019 (UTC)

Article contradicts itself about gamma radiation
The second sentence in the article says that fission produces gamma rays directly; but the 8th sentence says it doesn't. This needs to be resolved.

2nd sentence:
 * "Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release of heat energy (kinetic energy of the nuclei), and gamma rays. "

8th sentence:
 * " fission events normally result in beta and gamma radiation, even though this radiation is not produced directly by the fission event itself. "

Communpedia Tribal (talk) 16:48, 22 March 2021 (UTC)

Indeed, you're right. I changed it to

This releases additional energy in the form of beta particles, antineutrinos, and gamma rays. Thus, fission events normally result in beta and additional gamma radiation that begins immediately after, even though this radiation is not produced directly by the fission event itself.

OsamaBinLogin (talk) 23:23, 1 November 2023 (UTC)

Misleading graph about Chernobyl fission products
In the section Decay, the second graph (often stretching into the next section), the graph makes it look like some of these isotopes grow in their radiation, which is impossible. Esp Cs-137. But, the y-axis is labeled '% Contribution'. So, total radiation from Cs-137 does NOT increase, it just takes over and becomes the major part of the dwindling radiation, because the others have fallen off more quickly. Total radiation falls quickly from left to right.

A more informative and less deceptive graph would just show absolute radioactivity, not proportion. And, one could see that overall radioactivity falls over time. Even better, one of these area plots, that stacks the different sources of radiation, so the overall is visible as the top line.
 * Radiation can increase with time, if decay products have a short half-life. The first experiment that Marie Curie did was to compare the radioactivity of uranium with uranium ore. The ore was higher, which to her meant that there must be other elements. If you take a block of pure uranium and then wait, (alpha) decay products more radioactive will be produced, and so radiation increases. Gah4 (talk) 08:07, 20 February 2024 (UTC)
 * Radiation can increase with time, if decay products have a short half-life. The first experiment that Marie Curie did was to compare the radioactivity of uranium with uranium ore. The ore was higher, which to her meant that there must be other elements. If you take a block of pure uranium and then wait, (alpha) decay products more radioactive will be produced, and so radiation increases. Gah4 (talk) 08:07, 20 February 2024 (UTC)