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Re: Self Shielded Irradiators

Dear Kent

        You are right in your statement. To license an self-contained gamma
irradiator, like that you mention, Category I irradiator, besides the Safety
related aspects including Quality Assurance, two other points needs  special
attention from Regulatory Authority:

1) Contingency plans
2) Security 

About the first and the best  reference is Nordion International Inc.
(former Atomic Energy of Canada Ltd.), Manufacturer and Distributor of this
type of Gammacell at the following sites:

a) homepage http://www.mds.nordion.com/

b) direct contact to ask your questions of major concern on incident or
accident, http://www.mdsintl.com/nordion/contact.htm

About the second, security (physical protection) This is also a question of
concern. This subject, "Security of Radioactive Materials" is part of the
next International Conference on the Safety of Radiation Sources  and the
Security of Radioactive Materials, organized by the International Atomic
Energy Agency (IAEA) and co-sponsored by the European Commission (EC)
International Criminal Police Organization (Interpol) to be held in  Dijon,
France, 14 - 18 September 1998

A round table session will address international co-ordination of the
security of radioactive materials.

Special mention to the Interpol activities on illicit trafficking in nuclear
and radioactive materials

 The technical programme in security of radioactive materials will be:
 * Measures to prevent breaches in the security of radioactive materials
(from production to disposal);
 * Concepts of risk prevention applied to a situation where radioactive
materials are out of control:
 * Detection and identification techniques for smuggled radioactive materials;
 * Response to detected cases and seized radioactive materials, including
safe transport and storage;
 * Potential of criminal acts involving radioactive materials;
 * Importance of the awareness, training, exchange of information and
co-operation between regulatory authorities and customs, police and other
law enforcement agencies.

You can find the complete programme at the IAEA home page, (look at search
for International Conference on the Safety of Radiation Sources  and the
Security of Radioactive Materials) or ask to the Division of Public
Information:            <official.mail@iaea.org>

J. J. Rozental <josrozen@netmedia.net.il>
At 02:31 PM 3/31/98 -0600, you wrote:
>Those that are familiar with self shielded irradiators are aware of 
>the inherent safety of the devices under normal use.  I was asked 
>about radiological considerations in a disaster.  
>My initial impression is that because the shielding is made of lead, 
>and lead has a low melting point, that one obvious concern is a loss 
>of shielding in a fire.  Presumably the lead is encased in steel such 
>that this is unlikely to occur.  But at what temperature would the 
>structure fail?  Is this temperature likely to be achieved in a 
>serious building fire?  Is the device more suseptible to structural 
>damage at these elevated temperatures?
>Also are there other disasters which might create a major problem - 
>explosions (don't laugh, I'm sure that we are not the only one that 
>has seen the bomb squad at their facility), earthquakes (structural 
>damage to building causing the device to fall tens of feet onto a 
>hard, solid object), tornadoes, thermal shock (e.g., fire followed by 
>water from fire suppression system),  others?  
>So, what sort of disaster could affect the integrity of the shielding 
>or the sources?  Are there written standards that these devices must 
>meet?  Are actual tests performed on prototypes?  I would appreciate 
>references if possible.
>Kent N. Lambert, M.S., CHP
>Allegheny University of the Health Sciences
>Hahnemann Division
>Radiation Physics and Safety, MS 106
>Broad and Vine Streets
>Philadelphia, PA  19102-1192
>215-762-8768 (voice)
>215-762-7683 (fax)