Clarification : [ RadSafe ] radium source questions

[Robert Atkinson]

Hi Julian,
One aspect of the OSR program that may be of use is the LANL Special
Form Capsule that they developed to deal with this problem, quote below,

"Due to their age, a lack of available manufacturer data and unknown
origin, or the potential for leakage, some of the radioactive sealed
sources targeted for recovery by the OSR Project do not meet US
Department of Transportation (US DOT) Type A requirements. Sealed
sources that are special form can be shipped using US DOT Type A, 7A
packages, which provide increased flexibility in shipping. The OSR
Project has developed a sealed source overpack called the LANL Special
Form Capsule (SFC) Model 1 to provide a method to ensure US DOT special
form containment of radioactive sealed sources during transport. Sealed
sources which do not have current special form certification or
documentation for domestic transport can be made special form by field
encapsulation in a LANL SFC"

See < http://osrp.lanl.gov/special_form_capsules.shtml > and
<
http://osrp.lanl.gov/Documents/LAURS_Documents%20Page/LAUR-02-433%20(SFC
%20Model%201).pdf >

Use of the SFC (there are detailed drawings in the PDF link above) would
at least allow you to qualify them as sealed sources to current
standards.

Radium seems to be a particular problem; no one seems to want to dispose
of it. I have an interest in Ra226 luminised instruments (mainly from
aircraft). There are exceptions for clocks and watches (I'm also in the
UK) but nothing for the instruments. These are readily available at air
shows, curio shops and on-line auction sites. The sellers either don't
know or don't want to know about the hazards associated with these
items. 
A typical small (2.5" pressure gauge 1944) instrument reads 39.2uSv/hr
on contact (actually about 25mm source to detector centre) and 7.5uSv/hr
at 100mm. A larger 4" instrument (airspeed indicator) reads 112uSv/hr
contact and 25uSv/hr at 100mm. All readings were taken with a Canberra
ADM-300A (with current calibration) and background (0.2uSv) subtracted.
Both these gauges were for sale at small Aero-jumble. The measurement
geometry is not ideal as the instruments are effectively an array of
small sources. This is a significant amount of radiation. I would be
interested to know if there is any way of relating this to an activity.
The instruments are not totally sealed so it's uncertain that the
progeny are in equilibrium. If you keep an instrument in a plastic bag
for a few days progeny are easily detected on the bags inner surface.
A freeware calculator (RadPro 1.8) has a dose rate to activity
conversion but this gives a figure of 75MBq (2mCi) for the small
instrument and 250MBq (6.7mCi) for the larger one. I find these figures
hard to believe. 

Regards,
Robert Atkinson, Non HP professional UK.

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of JGinniver at aol.com
Sent: 13 May 2005 19:31
To: radsafe at radlab.nl
Subject: Clarification : [ RadSafe ] radium source questions

Dear all,
firstly my thanks go out to those that have responded with information
and  
offers of help with this issue.  As a result of the replies I realise I
should 
have included additional information in the original posting.  The  most

important of these is that I'm based in the United Kingdom.  I would
like to take 
this opportunity to apologise to the list for not including details  of
my 
position, employer etc. but unfortunately my employer has made it clear
that 
all my activities on this and other list should not identify them.   
Notwithstanding this it would have helped if I had indicated that I'm
based in  the UK 
and can't therefore make use of either existing facilities in the US, or
the US 
National Source Recovery programme mentioned by another list member in a

response to my original query.
 
I would however like to draw the list attention to this service, as I
think  
it is a great facility.  More details can be found at:

_http://www.doeal.gov/osrp/OSR%20Overview.htm_ 
(http://www.doeal.gov/osrp/OSR%20Overview.htm) 
 
The UK doesn't have such a facility, or even a national policy or
National  
Disposal Facility.  Large sources that exceed the criteria for LLW must
be  
conditioned/packaged in preparation for transfer to an as yet unbuilt
National  
ILW facility.  Current ILW stores at Nuclear Sites must be designed to
last  
the next 50 years as this is the possible time period before the
National ILW  
facility will become available.  There are, fortunately, some generic
package 
designs for which nuclear operators have been given "letters of comfort"
and 
it is to meet these criteria that I need the information on the source
design 
and construction.
 
The sources were manufactured in the late 1950s and early 1960s by the
then 
named Radiochemical Centre in Amersham, Buckinghamshire, UK.   They are
more 
commonly know as Amersham International, but have been called more
recently 
Nycomed Amersham and are now Amersham part of GE Healthcare.
Unfortunately 
they no longer make sources for industry and attempts at getting
information 
directly from them have failed.  I believe that Amersham did  supply
sources to 
the US, I came across references to them on the site run by  another
list 
member (Analog or is it Analogwell).  Consequently I would  appreciate
any 
information other list members may have on either these sources
specifically (model 
number RAN or RAN5).  Or alternatively generic  information along the
lines of 
the original request.
 
Thanks again to everyone who has responded.
 
Regards,
    Julian
 
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