Radiation sources

and any other non-chem subjects.
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Ocker
Posts: 911
Joined: 01 Jun 2006, 10:00
Job Title: Lab attendant
State/Location: NSW

Re: Radiation sources

Post by Ocker »

The lead seals in the radiation, then just make secure.
LeeBee
Posts: 3
Joined: 06 Jun 2017, 13:25
State/Location: WA

Re: Radiation sources

Post by LeeBee »

The sealed radioactive sources supplied to schools do not need any licencing or special storage, the activity is so small. Same for unsealed needle source for cloud chamber.They are sent internationally through the post in a plastic case or tube! They are manufactured by Spectrum Techniques in America. Activity over 10 uCi (microcuries) may require lead shielding according to them.
If you had all three "recommended for school" disc sources, Polonium-210, Cobalt-60 and Strontium-90 you would have a total of 1.02 uCi activity. Way below any requirement for shielding. Just store away from work areas where people spent a lot of time to be safe. To put things into perspective we receive 0.4 uCi (2 mSv) background radiation EVERY YEAR from radon gas all around us.
There is absolutely no need for radioactive pots for disc sources, they were for cup sources which are no longer available for school use, although it seems the suppliers are still happy to sell them which just adds to the paranoia surrounding this topic. Same with lead shielding for your discs.
And, if your lead lined boxes are old I would do a wipe test on them as they could be contaminated from previous materials and would therefore pose more of a hazard than the materials now inside!
The security and safe return of the sources are the most important thing to worry about with school disc sources.
Radioactive sands, and rocks such as Uranium that people may have collected over the years could have much higher activity.

See ARPANSA guide- Use of Radiation in Schools
https://www.arpansa.gov.au/sites/g/file ... /rps18.pdf
A1.3 SHIELDING
"Generally, the radiation levels in approved school experiments involving X-rays or radioactive materials are so low that no special shielding is required. However, it is important when using sources of radiation in schools to demonstrate the role of shielding as part of safe working practices."[/i]

Note: I would not purchase Polonium-210 as it has a half life of only 138 days. i use Americium-241 for an Alpha source, remove the sealed capsule from an ionizing smoke detector for that. (1.0 uCi) Cheers
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