[ RadSafe ] Half-life nonsense

Mon Jul 16 16:28:18 CDT 2012

Not really, it's quite common to have a low-level activity 
radioisotope with a long half-life and vice versa. As a stand-alone 
measured quantity (without considering decay) , the amount of 
activity is independent of the radioisotope's half-life.

At 05:15 PM 16/07/2012, you wrote:
>This sounds like the difference between low level radioactivity and 
>high level radioactivity.
>
>
>On 7/16/2012 9:29 AM, Brennan, Mike (DOH) wrote:
>>I deal (mostly) with environmental rad, but I also talk with people 
>>who use rad in the medical field.  For the medical folks, "long 
>>half-life" is anything more than about 100 days.  For me, Long 
>>half-life is when it is more convenient to write it in scientific notation.
>>
>>-----Original Message-----
>>From: radsafe-bounces at health.phys.iit.edu 
>>[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Jerry Cohen
>>Sent: Saturday, July 14, 2012 1:09 PM
>>To: The International Radiation Protection (Health Physics) Mailing List
>>Subject: Re: [ RadSafe ] Half-life nonsense
>>
>>Lets see if I understand this correcly---If it is man-made, it is bad (ie.
>>hazardous)
>>but naturally occuring is OK. Right???
>>By that standard, aspirin is a poison, and hemlock is OK
>>
>>At the HPS meeting in 1980, I gave a paper intended to address the longevity
>>nonsense by proposing a change in definition. We proposed that:
>>
>>Radionuclides with a half-life less than one million years be considered
>>radioactive,
>>
>>Radionuclides with a half-lifes between one million and one 
>>trillion years are
>>radiopassive,and
>>
>>Those with half lives greater than a trillion years (eg. I-129) are
>>radioquiescent (ie. stable elements)
>>
>>Somehow, the idea never caught on.
>>
>>
>>
>>
>>
>>________________________________
>>From: John R Johnson <idiasjrj at gmail.com>
>>To: Jerry Cohen <jjcohen at prodigy.net>; The International Radiation Protection
>>(Health Physics) Mailing List <radsafe at health.phys.iit.edu>
>>Sent: Fri, July 13, 2012 4:22:42 PM
>>Subject: Re: [ RadSafe ] Texas LLRW Site
>>
>>Jerry
>>
>>Isn't it because it does not occur in "nature". If I-129 is present it must
>>be "man made" and likely an indication of other isotopes being made.
>>John
>>On Fri, Jul 13, 2012 at 3:38 PM, Jerry Cohen <jjc105 at yahoo.com> wrote:
>>
>>>
>>>I wonder what makes I-129 a "radionuclide of interest". Its exceedingly
>>>long
>>>half-life makes it essentially a stable element, no different than the
>>>stable
>>>iodine that occurs naturally in most soils.
>>>
>>>Jerry Cohen
>>>
>>>
>>>Dear Radsafe,
>>>
>>>      From:    _jpreisig at aol.com_ (mailto:jpreisig at aol.com)    .
>>>
>>>
>>>      Hope you are all doing well.  HP  abstracts for the HP Society
>>>Meeting in Sacramento,
>>>California are out now, as a supplement to Health Physics magazine.
>>>Always interesting
>>>reading.  One item is on DU by Bob Cherry.
>>>
>>>      Operational Radiation Safety (another HPS journal)  has an article on
>>>Decommissioning of the
>>>Brookhaven Lab High Flux Beam reactor.  Fuel and spent fuel are  gone.
>>>Heavy Water is gone.
>>>Interesting reading.  I guess that's one way of totally stopping  the
>>>tritium leak source term.
>>>The offending leaking fuel storage pool was drained.  Goodbye.  Wonder
>>>what they'll do with the
>>>Brookhaven Medical Research Reactor.  I don't think there was anything
>>>wrong with it..
>>>
>>>      There's an abstract on the new Texas LLRW (Low Level  Radioactive
>>>Waste) facility and some
>>>modeling they did.  The radionuclides of interest are C-14, Tc-99,  I-129,
>>>possibly among others.
>>>I guess tritium is not that big a deal in such a facility, due to its short
>>>half-life.  These radionuclides
>>>are particularly mobile in the groundwater environment, as referred to in
>>>my earlier RADSAFE
>>>postings.  These Texas folks did some computer modelling and describe  what
>>>they did.  Wonder why
>>>they didn't just use Femwater-BLT (Suen and Sullivan???),  Lewater, Lewaste
>>>or similar computer
>>>codes.  Last I heard, Femwater-BLT was available for use on a personal
>>>computer.  It is or was
>>>available for a fee from the RSICC, the Radiation Shielding Information
>>>Center at Oak Ridge
>>>National Laboratory (USA).  Other Radiation computer codes are  available.
>>>Finally, if you see a computer
>>>code you are interested in, you can search it out on the internet, and then
>>>email the original
>>>programmers/designers for information on how to obtain such a computer
>>>code.  No big deal.
>>>
>>>      These newfangled small, modular reactors are also  addressed in an
>>>abstract.  Sounds like
>>>some of them will be deployed by the TVA, in the Tennessee Valley.
>>>Newfangled nuclear
>>>electricity for people/homes/businesses previously not on the electricity
>>>grid.
>>>
>>>      NJ Nuke plants and workers, thanks for the 50% of the  electricity (in
>>>NJ) that you are providing to
>>>air condition part of my home this summer!!!!  Take Care...
>>>
>>>      Regards,    Joseph R. (Joe) Preisig,  PhD
>>>
>>>
>>>
>>>
>>>
>>>
>>>_______________________________________________
>>>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
>>>
>>>
>>>________________________________
>>>
>>>From: "JPreisig at aol.com" <JPreisig at aol.com>
>>>To: radsafe at health.phys.iit.edu
>>>Sent: Thu, July 12, 2012 8:44:56 PM
>>>Subject: [ RadSafe ] Texas LLRW Site
>>>_______________________________________________
>>>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

Michael LaFontaine, P. Phys.  