Re: sky shine?

[steve hand <hand@wam.umd.edu>]

I believe it is NCRP 49 that has a section on skyshine including a diagram.  I can
fax the two pages to anyone who needs it - sorry I did not get the original message
requesting information.

Steve Hand
Radiation Safety
University of Maryland
hand@wam.umd.edu

gerald.lahti@exeloncorp.com wrote:

> Also see the ANS standard ANSI/ANS-6.6.1 [1979 ??].
>
> Another good source of skyshine info is the publications of Ken Shultis and
> Dick Faw of Kansas State University.
>
> Another key parameter in skyshine calculations is the gamma ray energy of
> the source.  The skyshine response of N-16 (6 MeV) is quite different than
> that of a source with less than 1 MeV gammas.
>
> * * * * * * * * * * * * * * * * * *
> NOTE ComEd is now EXELON -- see new email address below
> Jerry Lahti
> Exelon - Nuclear - Downers Grove, IL
> 630.663.6659
> gerald.lahti@exeloncorp.com
> * * * * * * * * * * * * * * * * * *
>
> > -----Original Message-----
> > From: Ted de Castro [SMTP:tdc@xrayted.com]
> > Sent: Thursday, November 02, 2000 2:04 PM
> > To:   Multiple recipients of list
> > Subject:      Re: sky shine?
> >
> > First - throw away the "contact reading" - its meaningless - they
> > virtually always are!
> >
> > I am not familiar with your nomenclature for the other reading.
> >
> > Get a good reading at a distance from the source of more than 3 times
> > its greatest extent.
> >
> > The skyshine will then depend on the solid angle subtended through the
> > open roof and simple calculations will only apply at 3 or more wall
> > heights away from the building.
> >
> > The British Standards Institution produced a document - Data On
> > Shielding From Ionizing Radiation - B.S. 4094: Part 1 1966 - that makes
> > the calculations easy.  Surely its been updated by now - and it wasn't
> > easy to get!
> >
> > I also recall a simplified - rule-of-thumb method that kinda almost
> > works.
> >
> > I may have some specifics off - but it went something like:
> >
> > Inverse square to a point about 2 meters above the roof and then inverse
> > square from there out to the point of interest THEN apply an appropriate
> > scatter factor for the air above the building.  I'd start with a
> > conservative factor of something like 10,000 as I recall.
> >
> > It been YEARS since I did such a calculation - so I may have some of the
> > specifics wrong - but the quick method was something like that.
> >
> > Surely SOMEONE out there will find it in their heart to correct any
> > errors I have made!
> >
> > Need more accuracy - use a canned program!  The more you can tell it
> > about source and building geometries - the more accurate it can be.
> >
> > Oh yeah - air attenuation (and build-up) counts.
> >
> >
> > mark sasser wrote:
> > >
> > > An area shielded. say a bldg.  with an open roof,
> > > say with a dose rate of 200 MR/HR.contact on the
> > > object  maybe 80 MR/HR GA.how would sky shine come
> > > into play on clear days? or any day? this is for
> > > boundry set points. Barriers. ect.
> > >
> > > =====
> > > mark sasser
> > > at duke99301@yahoo.com
> > > you can also reach me at duke9930@concentric.net
> > >
> > > __________________________________________________
> > > Do You Yahoo!?
> > ************************************************************************
> > The RADSAFE Frequently Asked Questions list, archives and subscription
> > information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>
> *********************************************************************************
> This E-mail and any of its attachments may contain Exelon Corp. proprietary
> information, which is privileged, confidential, or subject to copyright
> belonging to the Exelon Corp. family of Companies.  This E-mail is intended
> solely for the use of the individual or entity to which it is addressed.  If
> you are not the intended recipient of this E-mail, you are hereby notified
> that any dissemination, distribution, copying, or action taken in relation
> to the contents of and attachments to this E-mail is strictly prohibited
> and may be unlawful.  If you have received this E-mail in error, please
> notify the sender immediately and permanently delete the original and
> any copy of this E-mail and any printout.  Thank You.
> *********************************************************************************
> ************************************************************************
> The RADSAFE Frequently Asked Questions list, archives and subscription
> information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
begin:vcard 
n:Hand;Steven
tel;fax:301-314-9467
tel;home:(410)-535-3762
tel;work:(301)-405-3985
x-mozilla-html:FALSE
org:Radiation Safety Office;Department of Environmental Safety
version:2.1
email;internet:hand@wam.umd.edu
title:Health Physicist
adr;quoted-printable:;;Room 2124, Building 090=0D=0AChemical & Nuclear Engineering=0D=0ACollege Park, MD 20742;College Park;MD;20742;USA
fn:Steven Hand
end:vcard