[ RadSafe ] Radioactive contamination unearthed at formerrocket test site near Los Angeles - U.S. News

Douglas Minnema DouglasM at dnfsb.gov
Wed Dec 19 14:44:01 CST 2012


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

        From the NBC article:

"Technicians collected 3,735 soil samples from a corner of the 2,850-acre
hilltop lab where most of the testing was done. Of those, they found about
10 percent contained radioactive concentrations exceeding background
levels."

        Yep.  Time to panic.  No doubt about it.

Steven Dapra


At 01:14 PM 12/13/2012, you wrote:
> http://usnews.nbcnews.com/_news/2012/12/13/15878279-radioactive-contamination-unearthed-at-former-rocket-test-site-near-los-angeles

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