This Two Billion Year-Old Natural Reactor May Hold The Key To Safe Nuclear Waste

[Marlin]

This Two Billion Year-Old Natural Reactor May Hold The Key To Safe Nuclear Waste Disposal


https://www.forbes.com/sites/davidbressan/2018/08/14/two-billion-year-old-natural-reactor-may-holds-key-for-safe-nuclear-waste-disposal/#5234858e3c72

[RDTroja]

Interesting use of the word 'decay' to describe fission.

[Marlin]

Interesting use of the word 'decay' to describe fission.

Fission is a form of decay, just not commonly used. U236 undergoes transmutation or decay (fission) after a U235 atom absorbs a neutron.

But everybody knows that    or at least those of us in the industry the author is a geologist. 

[RDTroja]

Fission is a form of decay, just not commonly used. U236 undergoes transmutation or decay (fission) after a U235 atom absorbs a neutron.

That's why I called it interesting, not really wrong. Spontaneous fission is a decay mode, but most of what happens in a reactor is not really decay in the classic definition.

[Marlin]

That's why I called it interesting, not really wrong. Spontaneous fission is a decay mode, but most of what happens in a reactor is not really decay in the classic definition.

I guess I should have just pointed out that the author was a Geologist and left the rest off 


Sometimes less is more. 

[hamsamich]

I was taught spontaneous fission is decay but fission caused by a neutron hitting fissile material <10-14 secs is not decay.  But this is all just terminology.  I guess in the purest sense it is all decay.  Supposedly induced reactions are not decay....but then aren't all elements with minuscule half lives basically induced...since they are immediately produced by something and then go away immediately?  So if it is decay, then what is the half life for u-236 decaying by induced nuclear fission? anybody, anybody...Bueller....?

By the way, I tried to correct my geology professor when he marked my answer wrong when the question described u235 absorbing a neutron then splitting as decay (fission was not a option only none of the above.)  He mumbled something and said I'll look into it....mmmkay.

[Marlin]

Just to play  s advocate and keep this thread alive. U235 is fissile then when a thermal neutron is absorbed it becomes U236 an unstable element that undergoes a nuclear transformation we call fission forming two new elements. An unstable element that decays by alpha forms two new elements in a nuclear transformation we call decay.


So fission = transmutation = decay  

[scotoma]

That article is overly simplistic, incomplete in info, and contains many outright errors. I think we already have the key to safe nuclear waste that doesn't require a rare and expensive element. We just can't agree on where to store it.

[hamsamich]

So all transmutation is decay?  Wasn't taught that either.

[SloGlo]

of coarse, iffen yore a writer, yew probably pick up a dictionary for aide with words
https://www.merriam-webster.com/dictionary/decay
look up a definition two use
"2 : to decrease usually gradually in size, quantity, activity, or force"
n may bee an example too help yore understanding
"In the upside-down world of quantum theory, for instance, a radioactive particle decays and doesn't decay during any given period of time — and each result plays out in a separate universe.
—
Dan Falk /, NBC News, "What is the multiverse?," 22 May 2018"

[Marlin]

So all transmutation is decay?  Wasn't taught that either.

Just food for thought; any conversion of an element to another is nuclear transmutation, all decay and fission is transmutation, all fission (U236) is decay.

   Hmmm, did you accept everything you were taught as fact without question?

By the way, I tried to correct my geology professor when he marked my answer wrong when the question described u235 absorbing a neutron then splitting as decay (fission was not a option only none of the above.)  He mumbled something and said I'll look into it....mmmkay.

Just sayin' 

[hamsamich]

Never said I accepted it.  Just how I was taught.  Just a data point.  Since it is terminology....I don't care so much about that.  Like I said before...it probably is decay but just a very different version...or not.  I took geology in college after I had been nuclear trained by the navy world and the commercial world, so I brought it up to my geology teacher.  Calling u-235 splitting by neutron "decay" just seemed wrong, but maybe it should be classified as decay in a very broad way since u236 is supposedly formed for a very short time. Does this actually happen or is this just an easy way to explain things?  I would much rather call it fission first.   Still waiting for the half-life of u-236 "fission" decay if anybody can dig it up.  Hydrogen-7 is the shortest half life I could find approaching e-24 secs...so e-14 is childs play right?  But it is <e-14 so how much less....how quickly are the lions share of those neutrons and fission products coming out and does it matter?   If this is just terminology then this is kinda silly but terminology does make learning easier if it is strictly correct.  Seems like something vague.  It would be cool if the top 10 nuclear physicists chipped in here but that probably won't happen.  Darn.  Somebody send an email...

[Marlin]

Never said I accepted it.  Just how I was taught.  Just a data point.  Since it is terminology....I don't care so much about that.  Like I said before...it probably is decay but just a very different version...or not.  I took geology in college after I had been nuclear trained by the navy world and the commercial world, so I brought it up to my geology teacher.  Calling u-235 splitting by neutron "decay" just seemed wrong, but maybe it should be classified as decay in a very broad way since u236 is supposedly formed for a very short time. Does this actually happen or is this just an easy way to explain things?  I would much rather call it fission first.   Still waiting for the half-life of u-236 "fission" decay if anybody can dig it up.  Hydrogen-7 is the shortest half life I could find approaching e-24 secs...so e-14 is childs play right?  But it is <e-14 so how much less....how quickly are the lions share of those neutrons and fission products coming out and does it matter?   If this is just terminology then this is kinda silly but terminology does make learning easier if it is strictly correct.  Seems like something vague.  It would be cool if the top 10 nuclear physicists chipped in here but that probably won't happen.  Darn.  Somebody send an email...

Not really trying to disagree with you just being a bit of a troll to stretch the thread a bit. 

Definitions tend to vary by discipline and as for Navy training "there is the right way, the wrong way, and the Navy way".  My Navy Nuclear School, my Nuclear Propulsion Training Unit are empty lots and both of my subs are gone and the reactor compartments in the trench in Washington making that indoctrination a distant past. The term "Ustafish" was given to people who hung onto the last facility/boat as the right way to do things. I hope I have shaken that but I think we all tend to do it even if it is unconscious.

[hamsamich]

no they are all good comments...stuff like this is interesting.  would love to hear what a few top level phd researchers have to say.