From: email@example.com (B. Alan Guthrie)
Subject: Re: PBS Frontline, April 22
Date: 18 Apr 1997 20:41:30 GMT
In article <firstname.lastname@example.org>,
John McCarthy <email@example.com> wrote:
>Dennis Nelson <firstname.lastname@example.org> writes:
> > Mnestheus wrote:
> > >
> > > Message-ID: <3352A6DA.email@example.com>
> > >
> > > Somebody wrote:
> > >
> > > >I haven't seen any scientific studies showing radiation to be healthy
> > > Presumably the author of this quotel feel better after his carbon -14 has
> > > decayed away and spared him the ravages of low-level radiation.
> > I don't know how he feels about his C-14 levels but at least burning fossil
> > fuels doesn't contribute any C-14 to the atmosphere we breathe, unlike its
> > often touted compeditor nuclear power which makes C-14 from neutron activation
> > of atmospheric nitrogen. There were even gas cooled reactors which used N2 as
> > a coolant. You can imagine how much, 5,000 year half life, C-14 they produced.
>Dennis Nelson can imagine, and I can imagine. Very likely we would
>imagine differently. How about calculating? Burning wood does put
>C-14 into the atmosphere unless the wood is very, very old, i.e. many
>C-14 half lives of 5715 years. Ordinary nuclear power doesn't put
>C-14 into the atmosphere. I'm dubious about how much C-14 went into
>the atmosphere from the N2 cooled reactors.
>The important question is how the amount compared to what is alread
>there. If it is less than one part in a million, the impact is trivial.
I guess that I really do need to read Dennis Nelson offerrings a
little closer. This gem slipped right by me.
Let's look at the nuclear physics. Nitrogen is about 99.64% N-14
and the remain 0.36% is N-15. If N-14 absorbs a neutron, it
becomes N-15 which is stable. If N-15 absorbs a neutron, it
becomes N-16, which beta-decays to O-16 with a 7.11 sec
half-life. In other words, the neutron irradiation of nitrogen
in a reactor does not produce C-14.
There is (n,p) reaction in N-14 which produces C-14. The minimum
resonance is 11.30 MeV, which is substantially above the neutron
energy from fission.
B. Alan Guthrie, III | When the going gets tough,
| the tough hide under the table.
| E. Blackadder
From: jgd@rsiatl.UUCP (John G. De Armond)
Subject: Re: Nuke CO2 Emissions
Keywords: Nuclear CO2 emissions over total fuel cycle
Date: 27 Apr 90 20:36:33 GMT
firstname.lastname@example.org (Al Thompson) writes:
>|> This report lists CO2 emissions from nuclear reactors as "negligible",
>|> but added that a typical commercial nuclear plant emits
>|> "8-9.5 curies of radioactive carbon-14 annually", environmentally
>|> on par with natural gas fuel although the risks are "dramatically
Umm. I don't think so. I've not seen any soot piles forming outside
any plant stacks lately.
>I'm puzzled. How does the C-14 from a nuclear plant differ from the
>"naturally occurring" C-14 found in fossil fuel? How are the risks
>"dramatically different"? Is somebody trying to say they are different?
C-14 is considered in most health-physics circles to be harmless. The
low energy beta is so weak as to be unable to escape large molecules.
The only practical detection means are pass-through ionization chambers
and light fraction scintillation chambers. There is a tiny quantity
produced in reactors through the same neutron capture reaction with
nitrogen that forms it in nature. I've done a moderate biblio. search
of my H-P literature and only found one article and it refered to measurement
I suspect from the tone of the original report that the reporter has
confused Sr-90 with C-14. Sr-90 is a biohazard with a high
concentration factor in the body and is produced in large quantities
as a fission product. Very little escapes, though a couple of curies
a year would be reasonable.
>Then there is the K-40 emitted from fossil fuels. It has a very long half
Yep, We used to design whole body counters and while working with them,
I made an interesting observation. I can look at the K-40 concentration
in a person's body and fairly accurately predict lifestyle. The
highest levels of K-40 generally correlate well to the veggie-type health
nuts. Us meat'n'potatos eaters generally show the lowest level. This
is a fact that really confounds the professional worriers :-)