[ RadSafe ] formula and its derivation for rectangular extendedradioa...
Nick Tsurikov
nick.tsurikov at gmail.com
Sat Jul 13 01:41:12 CDT 2013
Dear all,
I don't know if this is asked for exactly, but I use a very simple equation
to estimate doses from containers full of minerals. All one needs is the
surface dose rate - which is better to be measured (but can, of course be
estimated as well). It goes like that:
EDR = EDRsurface × [1 – d/(d2 + A × B/3.14)0.5]
All in meters: d – distance to the source, A – height, B – width.
Seems to work rather nicely when the surface dose rate is above 5-6
microSv/hour, and takes about a minute or less to estimate. But I honestly
have no recollection by now where did I get it from... If anyone has a
reference to this - I'll very much appreciate it.
Kind regards
Nick
On Sat, Jul 13, 2013 at 2:00 PM, <JPreisig at aol.com> wrote:
> Mike Brennan/Radsafe:
>
> That's an interesting idea.
>
> MCNP modeling shouldn't take a week, if one already has MCNP on a
> PC. And PC's these days are
> so very powerful. Problem setup for a rectangular source should take
> about one day, and a first MCNP
> run should take 4 to 8 hours or less. Perhaps then, one can directly
> compare these Monte Carlo results with your measurements.
>
> In the olden days, I sure would like to have come up with an analytic
> and/or numerical solution. Solving problems this way forces one to
> seriously understand the problem. The book on Mathematical Physics by
> Arfken
> might be real helpful for getting an analytical or numerical solution.
> The
> book Numerical Recipes by
> Press, Teukolsky et al. has many different numerical solution algorithms,
> complete with Fortran or C
> computer code.
>
> Pick a solution method or two and get cranking. You can't use MCNP on
> the CHP exam!!!!
>
> Joe Preisig
>
>
>
>
> In a message dated 7/12/2013 5:05:48 P.M. Eastern Daylight Time,
> Mike.Brennan at DOH.WA.GOV writes:
>
> I know this is rather old school, but if the source really exists, and
> there are actually people who do things near it, how about a
> "tag-and-release" dosimetry program? Sometimes a day of measurement can
> replace a week of modeling.
>
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of dcoble tds.net
> Sent: Friday, July 12, 2013 12:15 PM
> To: The International Radiation Protection (Health Physics) Mailing List
> Subject: Re: [ RadSafe ] formula and its derivation for rectangular
> extendedradioa...
>
> Micro shield tm works also.
>
> On Friday, July 12, 2013, <JPreisig at aol.com> wrote:
> > Radsafe:
> >
> > I know this is overkill or too expensive or time consuming for
> > some people/facilities, but one could readily set up a rectangular
> > radiation source using MCNP (Monte Carlo Neutral Particle Program)
> > and do a Monte
> Carlo
> > Run (or a few) and solve the problem. Do some of the simpler
> > computer radiation codes model a rectangular source????
> >
> > Regards, Joe Preisig
> >
> >
> >
> >
> > In a message dated 7/12/2013 2:36:29 P.M. Eastern Daylight Time,
> > daniel.s.simpson at nasa.gov writes:
> >
> > George:
> >
> >
> >
> > I don't see a WORD file attached.
> >
> >
> > Daniel S. Simpson
> > Deputy Chief, Code 350 Occupational Safety & Health Division National
>
> > Aeronautics and Space Administration Goddard Space Flight Center
> > Greenbelt, MD 20771
> > (301) 286-2281
> > Fax: (301) 286-1745
> >
> >
> >
> > -----Original Message-----
> > From: radsafe-bounces at health.phys.iit.edu
> > [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of George
> > Chabot
> > Sent: Friday, July 12, 2013 2:22 PM
> > To: 'The International Radiation Protection (Health Physics)
> MailingList'
> > Subject: Re: [ RadSafe ] formula and its derivation for rectangular
> > extended radioactive sources exposure rate
> >
> >
> >
> > Regarding the rectangular source, attached is a Word document showing
>
> > the equation development. It is not possible to obtain a complete
> > algebraic solution to the required integration, but the resulting
> > equation is
> easily
> > solved using numerical integration.
> >
> >
> >
> > George Chabot
> >
> >
> >
> > -----Original Message-----
> >
> > From:
> > radsafe-bounces at health.phys.iit.edu<mailto:
> radsafe-bounces at health.phys.iit.edu>
> >
> > [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Danak,
> > Subhash
> M
> > CTR DOD CAPMED FBCH
> >
> > Sent: Thursday, July 11, 2013 10:28 AM
> >
> > To: radsafe at health.phys.iit.edu<mailto:radsafe at health.phys.iit.edu>
> >
> > Subject: [ RadSafe ] formula and its derivation for rectangular
> > extended radioactive sources exposure rate
> >
> >
> >
> > I like to review formula for rectangular radioactive sources exposure
> rate.
> >
> > Please provide one.
> >
> > I thank you.
> >
> >
> >
> > Subhash
> >
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