[ RadSafe ] Radioactive contamination unearthed at formerrocket test s...

Wed Dec 19 15:03:40 CST 2012

Hi,

     Well, where there are reactors, there is probably  some tritium.

     Sure radioactive decay of the tritium.  As  for dilution of the 
tritium via the plume spreading in space,
surely that will happen.  Don't know what the geology of this vicinity  is. 
 There is probably an
unsaturated zone on top of a saturated zone.  The plume water flow and  
radionuclide transport
can probably be modeled using a computer code like Femwater-BLT, more  
modern codes like
Lewater, Lewaste, that MODFLOW code the USGS likes and so-on.

    Assume the tritium is in some volume of dirt and that  the area gets 
some rainfall every month.
How the tritium is leached out of its source area depends on what the  
source material is like.
In Femwater-BLT the BLT stands for Breach Leach and Transport, I  think.  
Femwater-BLT can probably
be run on a PC nowadays.

    You can probably do a back of the envelope calculation  of dilution via 
the plume evolving, and consider
the rainfall as falling into a top dirt layer of some thickness.  I  don't 
know if there is a clay rock unit
under the top dirt layer which would cause the tritium to stay in the top  
dirt layer.

    Oh my, by the time I explain how to do this via a back  of the envelope 
calculation, it is almost easier
to get Femwater-BLT and run the computer model to get an answer.

   Good books on hydrogeology are Freeze and Cherry and de  Marsily 
(advanced).

   Take care... Joe Preisig

In a message dated 12/19/2012 3:44:55 P.M. Eastern Standard Time,  
DouglasM at dnfsb.gov writes:

Just  curious, what about tritium?

Twelve or so years ago, when I was doing a  safety management system review 
of the DOE-funded cleanup operations at that  site, there was clear (and 
acknowledged) evidence of a tritium plume moving  from the site into off-site 
areas.  I was surprised at the time because  there had not been any active 
reactors or other obvious sources for the  tritium at the site for many years 
before that time, but it was equally clear  that the plume was associated 
with one of the old test reactor  locations.

I understand that the intervening half-life of time will  have reduced the 
quantities further (please, no lectures on radioactive decay  :-) but at 
that time the quantities were easily measurable.  I'm not sure  that one 
half-life would have been enough to "make it go away."  Physical  dispersal of the 
plume might be enough to reduce it to below detectable, but I  don't have a 
good feel for that.

Doug Minnema, PhD, CHP
US Defense  Nuclear Facilities Safety Board

-----Original Message-----
From:  radsafe-bounces at health.phys.iit.edu  
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Cary  Renquist
Sent: Friday, December 14, 2012 1:54 PM
To: The International  Radiation Protection (Health Physics) MailingList
Subject: Re: [ RadSafe ]  Radioactive contamination unearthed at 
formerrocket test site near Los Angeles  - U.S. News

Here is the EPA's Fact Sheet on the study results:
EPA  Radiological Characterization Study Results http://j.mp/12dBJrt

It  lists some of the specific results in a table.
e.g.
Am-241: 3 positive  in the 0.05-0.06 pCi/g range
Cs-137:  291 positive in the 0.2-200  pCi/g range
Pu239/240:  14 pos in the 0.02-0.19 pCi/g  range
Sr90:  153 pos in the 0.08-21 pCi/g range  Etc.

---
Cary  Renquist
cary.renquist at ezag.com

-----Original  Message-----
From: radsafe-bounces at health.phys.iit.edu  
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Cary  Renquist
Sent: Friday, 14 December 2012 10:35 AM
To: The International  Radiation Protection (Health Physics) MailingList
Subject: Re: [ RadSafe ]  Radioactive contamination unearthed at 
formerrocket test site near Los Angeles  - U.S. News

U.S. EPA's Final Technical Memorandum Look-Up Table  Recommendations This 
is a link to a pdf that seems to have the background  threshold values for 
the nuclides of interest (Table 2 of attachment  1).
http://j.mp/QYILg4

Pursuant to an interagency agreement  between the U.S. Department of Energy 
(DOE) and U.S. Environmental Protection  Agency (USEPA), the USEPA has 
conducted a Radiological Background Study to  determine the background levels 
for radionuclides in surface and subsurface  soils associated with Area IV and 
the Northern Buffer Zone (Area IV Study  Area1) of the Santa Susana Field 
Laboratory (SSFL), located in Ventura County,  California. In addition, the 
USEPA is currently conducting a radiological  characterization of the Area IV 
Study Area to identify areas that exhibit  radionuclide concentrations in 
surface and subsurface soil and sediment above  background levels (herein, 
"soil" shall mean surface and subsurface soil as  well as surface and 
subsurface sediment unless otherwise  specified).

I didn't see a doc that has the presented results of  the soil samples, 
however, this article at least has some details:
Latest  soil tests at Santa Susana Field Lab site shows radioactive 
material remains -  LA Daily News http://j.mp/TSusGW

The EPA researchers collected 3,735  samples of mostly surface soil and 
found that of those, 500 contained  concentrations of radioactive materials 
that exceeded what is known as  background standards - or the levels occurring 
naturally in the environment.  Almost all were man-made radionuclides. Most 
of those samples contained  Cesium-137, and of those one sample reached 
levels up to 1,000 times above  background standard. There were 153 samples of 
Stronium-90 and of those some  hits reached levels that were 284 times higher 
than background.

Both  radioactive elements are considered dangerous to human health when 
present at  high levels.

"There were some hits that were elevated but for the most  part, they were 
in the range that we expected," said John Jones, federal  project director 
with the Department of  Energy.

Cary

---
Cary  Renquist
cary.renquist at ezag.com

-----Original Message-----
From:  radsafe-bounces at health.phys.iit.edu  
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Robert J  Gunter
Sent: Friday, 14 December 2012 6:38 AM
To: 'Robert Atkinson';  'The International Radiation Protection (Health 
Physics)Mailing  List'
Subject: Re: [ RadSafe ] Radioactive contamination unearthed atformer  
rocket test site near Los Angeles - U.S. News

Not a very informative  statement:  "10 percent contained radioactive 
concentrations exceeding  background levels."

This could easily be fill from another location or  different aggregate 
based on this statement alone.  Is it NORM or  Cs-137?

Robert J. Gunter, MSc, CHP
CHP Consultants/CHP  Dosimetry
www.chpconsultants.com
www.chpdosimetry.com
Toll Free:  (888) 766-4833
Fax:  (866) 491-9913
Cel:  (865)  387-0028
rjgunter at chpconsultants.com

________________________________
From:  Steven Dapra <sjd at swcp.com>
To: The International Radiation  Protection (Health Physics) Mailing  List
<radsafe at agni.phys.iit.edu>
Sent: Friday, 14 December 2012,  2:53
Subject: Re: [ RadSafe ] Radioactive contamination unearthed at  former
rocket test site near Los Angeles - U.S. News

Dec.  13