[ RadSafe ] Advection / Diffusion of Radon through Media
Emer, Dudley
EMERDF at nv.doe.gov
Mon Sep 22 15:28:03 CDT 2008
My team rode out Ike at the Houston Reliant Center where we had winds of 95 mph and massive amounts of water pouring in through the damaged roof. That of course was tame compared to what we found down south.
We used CASCADER to optimize the cover design and depth of burial for thorium and radium disposal at the NTS. It has produced results very close to the data obtained from instrumentation looking at barometric pumping of radon. The volumes detail the math and physics, model approach, and contains the FORTRAN 77 code and initial conditions specific to the Test Site.
While the system of coupled pde's is linear and could in principle be solved exactly it has not been solved to date for the general case. A solution was approximated by using a mixture of time convoluted ordinary difference equations and finite difference methods. The advection portions of the pde's used an implicit Euler-Lagrange numerical method.
Dudley Emer
Geophysicist
National Security Technologies
702-295-7808 office
702-794-5824 pager
702-521-8577 cell
-----Original Message-----
From: Dan W McCarn [mailto:hotgreenchile at gmail.com]
Sent: Monday, September 22, 2008 10:51 AM
To: Emer, Dudley; 'Radsafe'
Subject: RE: [ RadSafe ] Advection / Diffusion of Radon through Media
Dear Dudley:
One of those hurricanes, Ike, came right over my house near Houston. We had sustained winds of about 90 mph but not that much rain.
Can you tell me about your experience with CASCADER? Do you have the codes & documentation? Did you solve the Bateman equations analytically or numerically? Were you able to calibrate the model for the Nevada Test Site?
Dan ii
Dan W. McCarn, Geologist; 3118 Pebble Lake Drive; Sugar Land, TX 77479; USA
Home: +1-281-903-7667; Austria-cell: +43-676-725-6622
HotGreenChile at gmail.com mccarn at unileoben.ac.at UConcentrate at gmail.com
-----Original Message-----
From: Emer, Dudley [mailto:EMERDF at nv.doe.gov]
Sent: Monday, September 22, 2008 12:29 PM
To: Dan W McCarn; Radsafe
Subject: RE: [ RadSafe ] Advection / Diffusion of Radon through Media
Dan,
Sorry for the late response as I'm playing email catch-up after beginning deployed to the hurricanes for 3 weeks with FEMA US&R.
We've done some 1-D modeling here at the test site on the advective and diffusive transport of radon in alluvium that may help. The model is CASCADER which is a gas-phase isothermal 1-D fate and transport model using Bateman m-chain rules for radionuclide decay in dry soils. It contains both barometric pressure induced advection and diffusion with reversible and irreversible sorption for each radionuclide.
CASCADER: An M-Chain Gas-Phase Radionuclide Transport and Fate Model, Volume 1 - Basic Physics and Mathematics;
Lindstrom, F.T., Cawlfield, D.E., Emer, D.F., Shott, G.J., Donahue M.E.; June 1992; DOE/NV/10630-23
CASCADER: An M-Chain Gas-Phase Radionuclide Transport and Fate Model, Volume 2 - Users Manual for CASCADR8;
Cawlfield, D.E, Been, K.B., Emer, D.F., Lindstrom, F.T., Shott, G.J.; June 1993; DOE/NV/10630-57.
CASCADER: An M-Chain Gas-Phase Radionuclide Transport and Fate Model, Volume 3 - Heterogeneous Layered Porous Media;
Lindstrom, F.T., Cawlfield, D.E., Emer, D.F., Shott, G.J., Donahue M.E.; February 1993; DOE/NV/10630-41.
CASCADER: An M-Chain Gas-Phase Radionuclide Transport and Fate Model, Volume 4 - Users Guide to CASCADR9;
Cawlfield, D.E., Emer, D.F., Lindstrom, F.T., Shott, G.J.; September 1993; DOE/NV/10630-63.
A Simulation of the Transport and Fate of Radon-222 Derived from Thorium-230 Low Level Waste in the Near-Surface Zone of the Radioactive Waste Management Site in Area 5 of the Nevada Test Site; Lindstrom, F.T., Cawlfield, D.E., Emer, D.F., Shott, G.J., December 1993; DOE/NV/10630-58.
Regards,
Dudley Emer
Geophysicist
National Security Technologies
702-295-7808 office
702-794-5824 pager
702-521-8577 cell
-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf Of Dan W McCarn
Sent: Thursday, August 21, 2008 12:32 PM
To: 'Radsafe'
Subject: RE: [ RadSafe ] Advection / Diffusion of Radon through Media
Hello Group:
What I'm really fishing for transport equations for diffusion / advection including
time and decay or some papers / pubs that describe the mechanisms.
Dan ii
Dan W. McCarn, Geologist; 3118 Pebble Lake Drive; Sugar Land, TX 77479; USA
Home: +1-281-903-7667; Austria-cell: +43-676-725-6622
HotGreenChile at gmail.com mccarn at unileoben.ac.at UConcentrate at gmail.com
From: "Dan W McCarn" <hotgreenchile at gmail.com>
To: "'Radsafe'" <radsafe at radlab.nl>
Sent: Wednesday, August 20, 2008 7:18 PM
Subject: [ RadSafe ] Advection / Diffusion of Radon through Media
> Hello:
>
> Perhaps this has been done somewhere before: How does one go about
> estimating that component of radon that emanates from a granite or other
> material? There are several factors that I can think of:
>
> 1 - Nature of uranium mineralization: a) contained within minerals e.g.
> zircon, monazite; biotite and b) epigenetic mineralization via solutions
> precipitating U minerals in pore spaces and fractures. Most granites show
> secular equilibrium in the uranium series. Is this a macroscopic or
> microscopic property? Does the 5 MeV or so recoil dislodge the radon that
> far away from the origin in a mineral grain? Since granites are massive
> rock
> bodies, emanation of radon and subsequent decay would / could occur within
> the same granite, except near the margins.
>
> Does the accumulation of alpha decays e.g. U-238, Th-234, U-234, Th-230,
> Ra-226 ⇒ Rn-222 make it more accessible to mobilization? Because U-234 is
> more easily leachable than U-238 (Wyoming Basins, Kazakhstan), this
> suggests
> to me that the Ra-226 has been fairly well dislocated prior to decay to
> Rn-222.
>
> 2 - Dual porosity matrix - the nature of the permeability associated with
> fractures or porous fractions of a material vs. that portion that is
> contained within a mineral grain. I can imagine that if the rock was
> porous
> / permeable enough to be an aquifer, that the radon would advect at the
> same
> rate as the water. This is borne-out by borehole measurements in and near
> sandstone U deposits.
>
> 3 - Distance to a surface (e.g. fracture or actual surface of material)
>
> Empirically, does a 1 or 2 cm slab of uniform composition granite emanate
> at
> the same rate per unit surface area as a 10 cm slab?
>
> Dan ii
>
> Dan W. McCarn, Geologist; 3118 Pebble Lake Drive; Sugar Land, TX 77479;
> USA
> HotGreenChile at gmail.com UConcentrate at gmail.com
>
>
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