[ RadSafe ] RE: Transmutation
Dan W McCarn
hotgreenchile at gmail.com
Thu Oct 26 11:42:43 CDT 2006
Since I'm a "uranium geologist", I worry!
There are several "unreported" instances of anthropogene remobilization of
uranium from deposits: The Central Valley in California, The Chu-Saryssu
Basin in Kazakhstan, and the San Luis Valley in Colorado and likely many
other basins in the Basin and Range Province to mention a few. Or perhaps I
can state it as follows: Any water-bearing basin that has deposit
recognition criteria associated with sandstone uranium probably has some
degree of issue with anthropogene remobilization. Years ago, I discovered a
60 km long "uranium feature" (regional redox-controlled, roll-front) in the
San Luis Valley that I published on in 1982 and 2004.
McCarn (2004), "Natural and anthropogenic multi-pathway risks associated
with naturally occurring uranium mineralization in aquifers: Scoping
I still consider the San Luis Valley feature (30% of all potatoes in the USA
are grown there) "unreported" because the media never picked-up on the
issue. The locals would rather ignore it since it could have a negative
affect on potato contracts.
Uranium is not the issue, over 99% of the total dose is related to
radium-226 not to mention the 2KCi/year radon-222 released from the 1
million acre-feet of irrigation water (1500-2000 pCi/L over the valley at
large). Radium tends to hang in the upper soil zone whereas uranium tends to
flush through the upper soil zone and doesn't accumulate. See Leaching
But the geochemistry of radium is not as predictable as uranium. Some of
the U deposits that I'm familiar with have a miniscule radium signature
whereas others are very high. Most of these differences are said to be
related to the nature of the authigenic clays in the deposit and adsorption
of radium. The water directly from the deposits can have alpha activities as
high as 1 million pCi/L.
I'll be field sampling in the San Luis Valley again later this year, or
early next year for soils irrigated by wells producing from the feature
(10,000 wells in the Valley - perhaps 500 or more intercept the uranium
feature). And, the area has been "accumulating" radium for over 100 years
from farming / irrigation activities.
I reported my findings to the Center for Disease Control in Atlanta, and the
CDC re-did all the statistics for bone cancer for that area. The result was
that there was a significantly lower incidence of bone cancer (about 1/2)
compared to the rest of Colorado.
But you might be surprised to know that uranium mining and other mineral
mining sometimes involves a declaration of an "Aquifer Exemption" (see EPA,
Aquifer Exemptions) to declare the water unsafe for drinking because of the
nature of the mineralized water. This also occurs for petroleum leases and
EPA makes allowance for both mining and petroleum. The boundary is located
at an appropriate distance from the mineralized feature to prevent a well
"sweeping" mineralized water into the cone of influence. There's a
licensing paper in the above IAEA TECDOC (Pelizza & McCarn, 2004) that
describes the issue about Aquifer Exemptions.
Dan W McCarn, Geologist
Houston & Albuquerque
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of Robert J. Gunter
Sent: Thursday, October 26, 2006 09:20
To: radsafe at radlab.nl
Subject: [ RadSafe ] RE: Transmutation
Though the numbers speak for themselves, it seems like practically speaking
there is no difference between 1,000 y half life and 10^6. In fact the
longer lived stuff is "less" radioactive and less of a radiological threat.
After all, who is worried about the trace U radionuclides in the bricks of
their home, gravel in their walks,, and dirt in their yards (no I am not
saying we need to make baby carriages out of the stuff).
The thread from Dr Parthasarathy below discussing the article by Holloway
makes me wonder what the resulting dose is from U migrating from natural
deposits??? Do we need to establish "site" boundaries? What is the dose?
Do we need to relocate populations???
Since we don't currently worry about this (other than the odd Rn prong-if
the locals have money..), it seems that our TENORM problem is only
significant because we have decided to make it so.
Robert J. Gunter, CHP
Oak Ridge, TN
Ph: (865) 387-0028
Fax: (865) 483-7189
rjgunter at chpconsultants.com
Products and Services at:
Dear Mr Stewart farber,
The current thread in our news group reminds me of an interesting paper
titled " Uranium: don't leave it in the ground" written 16 years ago by by
Nigel Holloway in the "ATOM" magazine. He has worked out the effect of the
fuel cycle on total environmental radioactivity.
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