[ RadSafe ] Long-lived radionuclides

Fri May 27 13:03:44 CDT 2011

Hi, Dan.

I defer to your superior knowledge and experience on this subject,
especially as I agree with you.  To me, the first step in engineering a
barrier for a waste site is proper placement of the site itself.  And as
you point out, proper placement can provide such isolation from the
environment that the species that replaces the species that replace
mankind will be the next ones to worry about it.  

I admit to finding the Human Intrusion Scenarios in the appendix to be
difficult to believe in, as they assume people technologically advanced
enough to be drilling that deep, but lacking both information about WIPP
and the technology to image underground anomalies, such as the collapsed
remains of the WIPP facility.  Also, I have to wonder where in the
spectrum of risk to the hypothetical drilling rig crew hitting the rad
waste lies, compared to the other risks they face on the job.  

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Dan W McCarn
Sent: Friday, May 27, 2011 10:40 AM
To: 'The International Radiation Protection (Health Physics)
MailingList'
Subject: Re: [ RadSafe ] Long-lived radionuclides

Hi Mike:

Since I'm a geologist and have worked on LLRW, HLRW and wild
repositories
(those that have no engineering or geological barriers), as well as
hydrologic and geochemical characterization of repositories (including
WIPP
and Yucca Mountain) I'll enter this discussion on several fronts.  But
I'd
also like to add that I have significant experience in uranium
exploration
and development both in the USA, Central Europe and Central Asia.  I've
been
around the block once or twice, so to say.

1) Premise: It's not hard to find geological environments that can
contain
materials for 100K or even millions years or more with very low
permeability
and geological isolation.  This would include any of the massively
bedded
salts that occur on quite a few states.

2) Premise: It's not hard to find geological / geochemical environments
that
provide natural geochemical barriers and vertical constraints on
migration
of certain important radionuclides.

2a) Premise: It's not hard to find geological environments that restrict
migration of redox sensitive materials and allow precipitation and
concentration of those materials in naturally occurring reduction -
oxidation interfaces.  This gives rise to uranium deposits in otherwise
very
permeable sediments that are literally 10s to 100s of millions of years
old.

Discussion:
1) Ore forming processes inform geologists of the effectiveness of
geochemical barriers and concentration mechanisms that exist in very
many
parts of the world in many geologic media. 

2) Analogs for repositories have long been developed based on a number
of
different ore-forming processes and deposits.  These analogs are used to
appropriately site waste repositories and identify areas that are
inappropriate for waste sites.  The ores that concentrate can remain
stable
for 10s, 100s and even over 1 billion years as evidenced by the size and
scope of world-class pre-Cambrian unconformity-related uranium deposits
such
as Cigar Lake and McArthur River in Canada.

3) On the subject of "bad locations", identification of those areas
where
uranium can concentrate (ore-forming processes) can also be important to
prevent remobilization of elements (Se, As, U, etc) trapped in those
zones.
I prepared a paper a number of years ago investigation the
remobilization of
uranium & radium in agricultural areas where the source of water is in
aquifers that contain uranium deposits.  This is analogous to human
intrusion scenarios for the performance assessment of the WIPP.
Virtually
every major basin in the Western USA has at least minor sandstone
uranium
deposits.  Those that no longer have uranium did have it at one time.

Ultimately, the effectiveness if a repository is not the "engineered"
barriers, it is the recognition that the geological setting is the most
important characteristic, followed by human intrusion scenarios, usually
involving drilling into zones used by some distant generation (us, of
course) for permanent storage of radioactive waste.

Except for "Man" as an agent for releasing radionuclides into the
environment from a repository, proper setting of a site for nuclear
waste
can result in effective storage for 10s or 100s of millions of years.

Attached is a short appendix involving the E1E2 Human Intrusion scenario
for
WIPP.

Dan ii

--
Dan W McCarn, Geologist
108 Sherwood Blvd
Los Alamos, NM 87544-3425
+1-505-672-2014 (Home - New Mexico)
+1-505-670-8123 (Mobile - New Mexico)
HotGreenChile at gmail.com (Private email) HotGreenChile at gmail dot com

Attachement follows:
http://www.nap.edu/openbook.php?record_id=10143&page=123 
Improving Operations and Long-Term Safety of the Waste Isolation Pilot
Plant: Final Report (2001)

Page 123

Appendix B

Human Intrusion Scenarios

Oil, gas and other mineral resources are frequently found in association
with salt beds, such as the Salado, where the WIPP is situated. The
region
around the WIPP has known a high rate of drilling activities in the past
and
future energy trends indicate that there will be incentives to explore
the
region again, once institutional controls are removed (starting 100
years
after the closure of the repository). The risk of drilling directly into
the
repository and thus creating pathways for the release of radionuclides
into
the environment will then increase. Drilling through the repository
could
transport radioactive materials from the repository to the surface or
bring
water in contact with substances stored in the repository. The following
two
scenarios are possible sources of concern about the performance of the
repository and have been taken into account in the performance
assessment of
the WIPP.

1. If there were an oilfield water-flooding operation in the vicinity of
WIPP, a large amount of brine could flow from a leaky injection well and
induce a hydraulic fracture in the anhydrite (or marker bed) directly
above
or below the WIPP repository (Box B.1). If, at some later time, another
well
were drilled through the repository and into this brine-filled fracture,
the
high-pressure brine in the fracture could flow through the borehole and
flood the repository causing a release of radioactive materials. The
scenario is known as the Hartman scenario.

2. Direct drilling into the WIPP repository could allow circulating
drilling
fluid to bring radioactive materials to the surface through a borehole
as
cuttings or spallings. The situation could be serious if the repository
were
flooded with high-pressure brines. The Sandia National Laboratories
examined
three possible flooding scenarios, designated as E1, E2, and E1E2, in
their
performance assessment. These scenarios are briefly explained in Box
B.2,
Box B.3, and Box B.4 and they are described in detail in the Compliance
Certification Application (DOE, 1996).

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Brennan, Mike
(DOH)
Sent: Thursday, May 26, 2011 12:54
To: The International Radiation Protection (Health Physics) MailingList
Subject: Re: [ RadSafe ] Long-lived radionuclides

I think the difficulty of making "engineered barriers" that will
adequately contain material is often overstated.  I also think the
consequences of the break down, especially for radioactive material, is
almost always overstated.  And NEVER is it pointed out that for the long
half-life material the mass needed produce the same activity is vastly
higher than for the isotopes we pay more attention to.  

This is one of the places where I've seen an unholy alliance between the
anti-nukes and certain factions within the rad biz, as there is much
higher profit in arguing about how to build a facility that will last
10,000 or 100,000 years than there is in building a facility that will
reliably last 100 years, and will probably last 1,000 years if no one
tries to break it.

-----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: Thursday, May 26, 2011 11:00 AM
To: 'Jerry Cohen'; 'The International Radiation Protection (Health
Physics)Mailing List'
Subject: Re: [ RadSafe ] Long-lived radionuclides

The problem with long lived radionuclides is they contribute to off-site
dose for a long time.  This is obvious, but they may become limiting
factors
for waste pits in the long term when the "engineered barriers" break
down.
We prefer to ignore the other stuff....

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

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Jerry Cohen
Sent: Wednesday, May 25, 2011 11:55 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Long-lived radionuclides

Could someone please explain why there is such inordinate concern about
the 
 long-live radionuclides such as
 I-129, Pu-239, etc.
It seems to me that if long-lived species are of particular concern, we
should 
be most worried about the toxic stable elements (Pb, Cd, Hg, etc) which
will

persist forever.
Jerry Cohen

________________________________
From: Peter Miller <z3ix at kamprint.com>
To: radsafe at health.phys.iit.edu
Sent: Wed, May 25, 2011 11:20:58 AM
Subject: Re: [ RadSafe ] RadSafe Digest, Vol 639, Issue 1

>
>http://www.shef.ac.uk/mediacentre/2011/radioactive-iodine-japan-tsunami
-ear
thquake.html
>l
>
> 24 May 2011
> Expert discovers simple method of dealing with harmful radioactive
iodine

How does one separate the I-129 from seawater to heat it in a microwave
oven

with lead so as to immobilize it as Prof Hyatt's technique prescribes?

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the 
RadSafe rules. These can be found at: 
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit:

http://health.phys.iit.edu
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit:
http://health.phys.iit.edu

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit: http://health.phys.iit.edu
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit:
http://health.phys.iit.edu

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit: http://health.phys.iit.edu