[ RadSafe ] Hospital scanner could curb nuclear waste threat
John R Johnson
idias at interchange.ubc.ca
Sun Jan 31 17:03:36 CST 2010
Roy
Thanks for the clarifaction.
John
----- Original Message -----
From: ROY HERREN
To: John R Johnson ; radsafe at radlab.nl
Sent: Sunday, January 31, 2010 1:31 PM
Subject: Re: [ RadSafe ] Hospital scanner could curb nuclear waste threat
John,
The article stated "In the study researchers from The University of Manchester, led by Prof Jon Lloyd, took soil samples from the Oak Ridge nuclear facility in the United States and successfully tracked the movement of medical Tc through the soil". What they've written and what they are trying to communicate aren't necessarily one and the same. I believe that they are using the "medical Tc or T99m" as an indicator of the presence of the longer lived T99. They're looking for the energy signature from the decay of the shorter half life T99m, and detecting it on the banks of detectors on the "Hospital Scanner". The Hospital Scanner's gantry has been designed to hold a large patient and would therefore would hold a very large soil specimen. Perhaps the large number of NaI or solid state detectors in each bank of detectors and their relative sensitivity, or the large sample size confers an advantage to this type of testing. My question and the issue I don't understand is why this method of sampling is preferable to using "traditional" sample counting method such as a fully shielded liquid nitrogen cooled Germanium detector (see http://en.wikipedia.org/wiki/Semiconductor_detector).
A Hospital Scanner's cost is enormous, and unless one can borrow one after hours, it's not a practical method for counting samples. The hospital that I work at has had a succession of Nuclear Medicine Scanners over the years that I've worked there. I can tell you from first hand observation that as these devices have become more and more complicated with the addition of more and more features, such as CT, they are constantly breaking down. The Nuclear Medicine Technologists' blame the manufacturer or their service representatives for the scanners breaking down, and the service representatives blame the Nuclear Medicine Technologists misuse/lack of training or they blame the hospital's dirty power supply for frequent breakdowns. I now know most of the service representatives by sight and name...and I don't work for Nuclear Medicine. Needless to say, if I were counting environmental samples, I wouldn't want to get into the fray over who is responsible for the cause of one of these enoumously expensive scanner breaking down.
Roy Herren
------------------------------------------------------------------------------
From: John R Johnson <idias at interchange.ubc.ca>
To: *** ****** <royherren2005 at yahoo.com>; radsafe at radlab.nl
Sent: Sun, January 31, 2010 7:17:18 AM
Subject: Re: [ RadSafe ] Hospital scanner could curb nuclear waste threat
Roy
They are talking about Tc-99 (halflife = 21200 years), not Tc-99m (halflife = 6 hours).
John
***************
John R Johnson, PhD
CEO, IDIAS, Inc.
4535 West 9th Ave
604-676-3556
Vancouver, B. C.
V6R 2E2, Canada
idias at interchange.ubc.ca
----- Original Message ----- From: "*** ******" <royherren2005 at yahoo.com>
To: <radsafe at radlab.nl>
Sent: Saturday, January 30, 2010 4:25 PM
Subject: [ RadSafe ] Hospital scanner could curb nuclear waste threat
I am preplexed by the following article. Perhaps someone can explain the rational behind using a "Hospital Scanner", to perform environmental sample counting.
*** ******
Public release date: 29-Jan-2010
Contact: Alex Waddington
alex.waddington at manchester.ac.uk
01-612-758-387
University of Manchester
Hospital scanner could curb nuclear waste threat
Medical equipment used for diagnosis of patients with heart disease and cancer could be a key weapon in stopping nuclear waste seeping into the environment, according to new research.
A team of scientists from the Universities of Manchester and Leeds have joined forces with experts in nuclear medicine at Manchester Royal Infirmary, using medical gamma-ray cameras to track radioactive isotopes in soil samples from a US civil nuclear site.
This is the first time the technique, which is used in hospitals for heart, bone and kidney scanning, has been used to study the environmental behaviour of nuclear waste – and its success could help scientists find new ways of using bacteria to control the spread of radioactivity.
Radioactive isotopes of the element technetium (Tc) are produced in bulk by nuclear facilities, while a specific isotope of Tc with a very short life is routinely used as a medical tracer in human bodies.
Nuclear fission of Uranium has released tonnes of Tc from nuclear facilities over the past decades, with the element remaining radioactive for thousands of years.
But although the short lived medical isotope is chemically indistinguishable from that in long lived waste, it can be used safely in tests.
In the study researchers from The University of Manchester, led by Prof Jon Lloyd, took soil samples from the Oak Ridge nuclear facility in the United States and successfully tracked the movement of medical Tc through the soil.
Scientists at The University of Leeds were then asked to verify the observations using a special microscope technique called Transmission electron microscopy (TEM).
With the help of DNA analysis the Manchester team confirmed that certain microbes – and particularly some that use ferric iron for energy – can fix Tc in place in soils.
Researchers found that nearly all the Tc remained fixed when ferric iron was present with these 'iron-reducing' bacteria.
This finding itself is not new – Professor Lloyd and his colleagues had previously reported that microbes in laboratory cultures could perform this role in fixing Tc.
But the researchers' success in using the gamma camera could see the technique being used to probe how Tc and ferric iron move together in far more complex soil systems more representative of the 'real world' – helping develop future remediation techniques.
Prof Jon Lloyd from the School of Earth, Atmospheric and Environmental Science (SEAES) at The University of Manchester, said: "Using this medical scanning technique we were able to explore, in real time, the mobility of one of the most problematic and mobile radionuclides in sediments.
"Our success will allow scientists to accurately monitor the success of new biological methods in trapping radioactive elements in sediments and stopping them spreading further into the natural environment."
The findings coincide with the opening of a new Research Centre for Geological Disposal at The University, supported by a £1.4m endowment from BNFL, while a new Nuclear Medicine Centre recently opened at the Manchester Royal Infirmary, as part of the £500m Central Manchester Hospitals development.
Prof Lloyd added: "Investment in these two diverse but important areas of scientific research has helped bring about interesting and unexpected research findings that could ultimately have great benefit for society."
###
Notes to editors
Prof Lloyd is available for comment by arrangement. For more information please contact Alex Waddington, Media Relations Officer, UoM, Tel 0161 275 8387 / 07717 881569.
The research was published in a special edition of the American Chemical Society journal Environmental Science and Technology. A copy of the paper, 'Probing the Biogeochemical Behaviour of Technetium Using a Novel Nuclear Imaging Approach' is available on request.
_______________________________________________
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://radlab.nl/radsafe/radsaferules.html
For information on how to subscribe or unsubscribe and other settings visit: http://radlab.nl/radsafe/
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
More information about the RadSafe
mailing list