[87810] in Cypherpunks
Re: russia_1.html
daemon@ATHENA.MIT.EDU (S. M. Halloran)
Tue Oct 7 03:38:04 1997
From: "S. M. Halloran" <mitch@duzen.com.tr>
To: cypherpunks@cyberpass.net
Date: Tue, 7 Oct 1997 10:11:24 +200
In-reply-to: <199710070641.IAA02251@ankara.duzen.com.tr>
Reply-To: "S. M. Halloran" <mitch@duzen.com.tr>
> I think this comment is in error. Plutonium has a half life on the
> order of 250,000 years, so very little decay products would build up
> in 6 years. The tritium used in thermonuclear weapons has a much
> shorter half life, and would need to be replaced about that often.
Since radioactive decay is first-order, the following equation
applies:
N = N exp(-kt)
0
where N=amount of material at time 't'; N = amount of material at time
t; k=decay rate constant; t=time of interest.
The decay rate constant (k) for first-order decay processes can be
expressed as k = ln(2)/half-life.
Hence the equation can be expressed as follows:
N / N = exp(-[ln(2)/half-life]*t)
0
N / N will express the amount of substance remaining as a percentage
0
of the original.
Plugging in the numbers:
exp(-[ln(2)/250,000y]*6y) = 99.998%
Hence, ca. 0.002% (actually less than that) of the material has
decayed. It may be the case that even this minute amount of
"impurity" could poison something like weapons-grade material, but I
am not a radioactive materials expert.
Mitch Halloran
Research Biochemist/C programmer/Sequioa's (dob 12-20-95) daddy
Duzen Laboratories Group
mitch@duzen.com.tr
