All radio active waste should be properly disposed with a minimum of delay. They must not allow to accumulate in the laboratory.A record must be kept for radiological waste disporsal containing type of waste, date, nuclide activity and means of disposal. In the nuclear medicine laboratory, wastes are divided in to following groups and they are disposed in separate methods.
1. Liquid waste
2.Liquid scintillant waste
3. Solid waste of low activity
4. Clinical waste and biological cotaminated waste
5. Solid waste of higher activity
6. sharp objects
7. Gaseous waste
1. Liquid Waste
- Pour radio active liquid into laboratory sink designed for the purpose and wash away with plantiful running water.
- Discharge all beeta particles emitters except strontium 90 and gamma rays emitters with half-lives of less than one year,upto 2MBq without regarding to disporsal operation. but if large activities are involed, ask radiation protective supervisor to approve the disposal.
- Consult a radiation protection adviser, if the monthly total liquid waste discharged from laboratory is likely to be exceed 200 MBq.
- Don’t discharge inflammatory, toxic or corrosive Radio active liquid to drain.Arrange an alternative way to dispose them.
2. Liquid Scintillant Waste
i.Bio Degradable Scintillant Fluids
- Decant the fluid in to designed laboratory sink and wash away with copious stream of water.
- Dispose empty vials as ordinary domestic or laboratory refuse.
ii. Radio active Scintillant Fluids
- Disposo the liquid into a designated laboratory sink.
3. Solid Waste of Low Activity
- Dispense the harmless solid waste into non-radioactive domestic/ laboratory waste for disposal by the routine waste disposal service. If the radio activity is less than 400KBq activity per cubicmeter of waste.
4. Clinical waste and Biologically Contaminated Waste
- Incinerate the waste.
5. Solid Waste of higher Activity
- Seperate the waste from low activity waste and dispose into suitable container which is sealed to prevent desposal of contents.
- Keep the volume of waste packsge as small as possible.
- Label the waste container with radio active symbol and send to the appropriate dwpartment for desposing.
- Package the radio nuclides with half-lives less than 100 days.
- Package the bilogically contaminated material of higher activity separately from all other radioactive waste.
6. Sharp Objects
- Collect all sharp object such as needles,Pasture pipettes and glass fragments in a sturdy box (preferably plastic bin) for disposal as clinical waste.
- If there are contaminated with low radio activity materials, handle them as described in solid waste of low activity.
7. Gaseous Waste
- Laboratory should get the approval for disposal of gaseous waste.
- Discharge radio active gasses, vapours and aerosols into the atmosphere via fume hood / safety cabinets but the limits should be imposed by the authority.
Reference
- Local rules for the uses of unsealed sources of radioactivity in the Royal Victoria Infirmacy, The medical Scool – the Dental hospital and Dental School Newcastle upon Tyne, 1998 Revised edition, page no 16 – 19.