Re: Japanese nuclear accident: Did the reaction oscillate?

[Kerembaev@cs.com]

Douglas,

Do not forget the natural phenomena in South Africa.
That reactor has been around for a while and as far as I know, it is still 
sustaining fission.
Emil.
kerrembaev@cs.com

In a message dated 11/29/99 7:42:31 Pacific Standard Time, 
Douglas.Minnema@ns.doe.gov writes:

<< 
 Bjorn and others,
 
 Your are quite correct.
 
 Depending on the initial conditions, a criticality accident can indeed
 oscillate for some time period until the system thermally equilibriates, and
 then it can achieve a quasi- steady state mode of operation, which is
 exactly what seems to have happened in Japan.
 
 
 Note that this is also what happened in the Russian criticality accident of
 1997 with the metal system.  There was no liquid, and the heat losses were
 sufficient to not allow the fuel to heat up to melting; consequently the
 system operated until it was physically dismantled by a robot after a couple
 of days.
 
 A very simple but effective model for this type of system is the
 point-reactor kinetics equations, which can be found in most nuclear
 engineering text books. 
 
 Hope this helps,
 
 Douglas M. Minnema, PhD, CHP
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