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From: bl@hplabsb.UUCP (Bruce T. Lowerre)
Newsgroups: net.sci
Subject: Re: Safe Reactors?
Message-ID: <3490@hplabsb.UUCP>
Date: Mon, 19-May-86 20:25:01 EDT
Article-I.D.: hplabsb.3490
Posted: Mon May 19 20:25:01 1986
Date-Received: Fri, 23-May-86 06:08:05 EDT
References: <226@prometheus.UUCP> <421@ccird1.UUCP>
Organization: Hewlett Packard Labs, Palo Alto CA
Lines: 27

> OK, this article mentions the graphite reactor, which wasn't too safe.
> It also mentions the BWR reactors (like 3 mile Island :-).
> There are also the Sodium (or "breeder") Reactors which run even hotter
> than graphite?
> 
> What about the Fort St Vrain "argon/freon" reactor in Colorado?  Is
> this design any safer?  Is the Ft. St. Vrain reactor info included
> in descriptions of reactors?  Are there any other such reactors?
> 
> What other options are available to make a really safe reactor?
> 
> Would smaller reactors be better than large ones?
> 
> I'm curious as to whether the "Boiling water is best" approach
> taken by the navy in their "boat powerplants" is really apropriate
> in the context of large plants, often located near populated areas.

What is your definiton of safe?  The worst case scenario for the water
moderated reactor (i.e., Three Mile Island) is to uncover the core
and let the heat get out of hand.  Well, the core at TMI was uncovered,
the heat got out of hand, and guess what?  The core did NOT melt, it
disintegreated and the damage was held within the containment building.
The water moderated reactor needs the water to "moderate" the neutrons
(absorb the energy to thermal level) for the fission process to occur.
If the water is removed then the reaction stops.  The problem with
uncovering the core is the heat generated by the decay of the fission
by-products.