Talk:Nuclear fission product

message: 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)
replies: text: So, go to work DV8 2XL 15:38, 5 November 2005 (UTC)

text: 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)

message: 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)
replies: text: 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)

text: I concur - the statement is correct.  But it is oddly positioned here without context.  PJG 04:42, 10 January 2008 (UTC)
thread_title: Sum of fission product atomic masses

message: 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)
replies: text: 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)

text: 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)
replies: text: 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)

text: 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)
thread_title: Update

message: 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)
thread_title:  Claim that FPs less active than "original ore" in several hundred years 

message: 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)
thread_title:  Chemical hazards? 

message: 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)
thread_title:  iodine 

message: 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)
thread_title:  Questionable Half-Lives Versus Beta Decay Rates for Strontium Isotopes 

message: 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)
thread_title:  independent vs. cumulative 

message: 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)
thread_title: Article contradicts itself about gamma radiation

message: 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)
thread_title: Misleading graph about Chernobyl fission products