atmospheric

[Ricky Khaloo <khaloor@candu>]

 Luis,
>     I'm not sure that I fully understand what you want or why you need it 
(this  
> is most important in light of Gov't regs and guides).    Anyhow here goes.  
> Gaussian models are  conservative ways of predicting atmospheric dispersion 
and 
> the uncertainty is at best, 20%.  atmospheric dispersion factors (Chi/Q) are 
> dependent on the receptor and the effective height of release.  By that I mean 
> if you have a person at coordinates (x,y,z) and you are looking at the effect 
of 
> the source coming out at a height, H,  the equation for Chi/Q  considers y and 
z 
> directly ie Chi/Q=(e-y^2)(e-(z+H)^2 * 1/(pi*sigma y*sigmaz) plus some other 
> stuff).Ok.
>  In it simplest form (ie if we consider ground level release and receptor at 
> ground level,that is for y=0, H=0 and z=0 then Chi/Q =1/(pi*mean 
> windspeed*sigmay*sigmaz) where
>  sigma y, the horizontal std dev is dependent on x and pasquill stability 
> category (if you subscribe to that way of categorising things).
>  sigma z, the vertical standard deviation depends on x, the stability category 
> and the meteorological roughness length. Ah ha by meteorological roughness 
> length i mean the effect of surface roughness (ie your hills etc).  In 
general, 
> the rougher the terrain, the greater the dispersion (makes sense); sigma z is 
> larger for rougher terrain and consequently Chi/Q is numerically smaller. 
>  
> If i have confused you thoroughly, please E-mail  me directly  to continue  
the 
> confusion. 
> 
> As an aside, from a dispersion point of view, rolling hills around the reactor 
> are not as much trouble as lakes and other large water bodies.  Then you can 
> have real troubles!
> >    
> >    > 
> > > Greetings to who may read this! I have a question concerning the gaussian
> > > plume model. Does the effective height of the plume take into account the 
> > > relative height of the receptor. In this I mean if there is rolling hills
> > > around the reactor, how does one take this into account. Please educate 
me!


--

Ricky Khaloo                        
                                      e-mail:   Khaloor@candu.aecl.ca
                                      Phone: (905) 823-9040, Ext. 4532
                                      FAX: (905) 823-8006
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AECL CANDU                              
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