RE: radioactivity from fossil fuel power stations

["Careway, Harold A. (PS, NE)" <Harold.Careway@gene.GE.com>]

Just for fun and based only my personal experiences in southern Ohio coal

mines.



Firstly, I agree with Ruth's comments and know of few mines which are

back-filled though I understand some of this is being done in areas of West

Virginia where the land can be turned to commercial use.



Some additional radon release can be realized from coal mines through the

following mechanisms:



1.  Strip mines are generally large v-like gouges in the earth with the

sides sharply sloped and a road at the bottom.  Where the surface area

present to the atmosphere prior to the mine was just the local surface, the

area after the mine more than doubles (i.e. both sides and the road).  Given

that the radon production to the atmosphere is roughly a function of type of

soil and surface area, then the strip mine will cause some small increase in

radon release (via diffusion) to the atmosphere because of the additional

surface present.  I suspect I would have a hard time measuring it.



2.  Deep tunnel mines slope into the earth with multiple branches.  Again,

because of the tunnel surface area presenting a sink to radon diffusing

through the ground, radon in the tunnel air will build up (remember all

those folks around the turn of the century who traveled to mines for the

mineral air) to the extent that the air turn over permits the build up.

Most coal mines have ventilation shafts, and the variation in local air

pressure between the tunnel face and the vent shafts drives significant air

currents through the tunnels (like being in a cool moist hurricane sometimes

when you stand at the face).  Here is an area where I'm sure it would not be

hard to measure the additional radon output.  



I make no claims as to magnitude or consequences, only note that some

increase (size unknown) will be realized.



Hal



-----Original Message-----

From: RuthWeiner@AOL.COM [mailto:RuthWeiner@AOL.COM]

Sent: Monday, August 06, 2001 11:42 AM

To: blc+@PITT.EDU; loc@ICX.NET

Cc: radsafe@list.vanderbilt.edu

Subject: Re: radioactivity from fossil fuel power stations





In a message dated 8/3/2001 12:59:28 PM Mountain Daylight Time,

blc+@PITT.EDU 

writes:



<< 

    -- My statement here is a simplification of a much more

 complicated analysis, given in the paper cited, but I will try.

    When the carbon in the coal is burned, it disappears from the

 ground. The volume of the ground that it occupied is then taken by other

 rock or soil which contains uranium, and therefore eventually serves as a

 source of radon. The carbon in the coal cannot serve as a source of radon.

 The uranium impurity in the coal is returned to the ground eventually.

    In other words, the carbon in the coal takes up a volume in the

 ground which produces no radon, while the rock that takes up that volume

 when the coal is removed does produce radon. 

  >>

Like Dr. Gawarecki, I am confised about something:  First of all, as you 

point out, the radon didn't come from the carbon content of th coal in the 

first place, but from any uranium, thorium, etc. in the ore removed from the



ground with the mined coal.  When coal is mined, the volume of material in 

the remaining unmined ore body is decreased.  To the extent that the unmined



material in the ground releases radon, it does so onloy when there is 

additional disturbance, as when more coal is mined.  In undisturbed rock, 

radon is apparentlyt not released.  Thus, unless there is additional mining,



there is not going to be additional release of radon -- I mean, it's there

in 

the first place because it is trapped in  the rock when it is produced by 

actinide decay.

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