Disposal Procedures

Management of Radioactive Waste

• Decay• Dilution• Landfill

Waste Handling

• Decay Considerations

– Half-life– Energy/ Shielding– Storage/decay

space

Gaseous Waste

Fumes GasesDusts Vapors

Release Limit is Set for each isotope by CNSC

See Table 5 in the Manual for details

Liquid Waste

• Aqueous• Organic – includes ALL

scintillation cocktails• Aqueous Organic Biodegradable

Waste Disposal – Liquid

Maximum allowable activity

   

Tritium 370 kBq/l

Carbon-14 37 kBq/l

Sulphur-35       3.7 kBq/l

Phosphorous-32 

3.7 kBq/l

Phosphorous-33

3.7 kBq/l

Chromium-51  3.7 kBq/l

Iodine-125 0.37 kBq/l

Liquid Waste

• Decay P-32, S-35 etc• Drains• Red Plastic Solvent Containers• Fume Hood (small amounts)

Red Solvent Waste Container• How much C-14 is allowed in

one container?

R.L. x Volume=Activity limit per container

37 kBq/l x 5 litres= 185 kBq

C-14 Release Limit =37 kBq/l

Container volume = 5 litres

185kBq/5 liters= (185,000 dps/5 l) x (60s/1min)

= 11,100,000 dpminute/5 l

@ 100% effic = 11,100,000 cpm allowed in 5 liters (5000ml)

Count 1 ml = 2220 counts is allowed.

- Separate scintillation cocktails used with different isotopes. e.g. H-3, P-32

- Count a sample of your scintillationwaste periodically.

- Separate ‘hot’ cocktail samples if limits for disposal are approached.

Dilution – Not Recommended• How to dispose 46 MBq of C-14 in non-

toxic wash water?

C-14 Release Limit = 37 kBq/l Activity = 46 MBq Water flow = 10 litres/min

Activity / RL = # of litres required

46MBq / 0.037 MBq/l =1243 litres

Litres / Water flow = Dilution time required

1243 litres / 10 litres/min = 124.3 min

Water INWate

r OUT

Hot solution

Diluted waste

Contact HSE before considering using this method to dispose of waste…

Solid Waste – Low Activity

• Decay

• Landfill

Follow release limit AND

2.5 Sv/h at the surface

WASTE Disposal - Solid

   

Tritium 3700 kBq/kg

Carbon-14 370 kBq/kg

Sulphur-35       37 kBq/kg

Phosphorous-32  37 kBq/kg

Phosphorous-33 37 kBq/kg

Chromium-51  37 kBq/kg

Iodine-125 3.7 kBq/kg

And less than 2.5 Sv/hr at the surface

Timed Disposal

www.ubc.ca/okanagan/hse/safety/radiosotope.html

Decay time for 9.25 MBq of P-32 in 1.0 kg?

Nf

No

-0.693

lnx T1/2 = T

T1/2 =14.3 daysNo=

Nf= Thus T=

• As waste is generated, deface all radiation warning labels and place into lined radioactive waste container - Lid and Label

SOLID WASTE – Low Activity

(TABLE 5 in Manual)

•When full - complete and attach Low Activity Waste (LAW) label and place bag in decay storage area - note disposal date on calendar

REMOVE THIS SHEET ON DISPOSAL DATE AND SAVE WITH YOUR RECORDS. COMPLETE YOUR ANNUAL INVENTORY WITH DISPOSAL

INFORMATION

RADIOISOTOPE : ________Activity to decay ______MBq (FROM YOUR RADIOISOTOPE DATASHEET)

Survey meter reading at surface of box ____ uSv/hr

Caution Radioactive Material Low Activity Waste for Decay

Permit Holder(PI)/Lab ________________ Waste Generator Name _______________Lab Contact Phone # _______________

Box #___Initial Date _____________Disposal Date _____________Actual Date of Disposal ____________Disposed by _____________________

-Solid materials: vials; pipet tips; centrifuge tubes;gloves; paper

BUT… Please minimize your solid waste being held for decay or material requiring shipment for disposal.

Website: Useful tips : Maximum activity levels for immediate disposal

*When Disposal date arrives check that waste is less than the defined Release limit and less than 2.5 Sv/hr (0.25 mR/hr) at the surface.

*Enter disposal info on inventory sheet

**Contact HSE for disposal of Radioactive Wastes**

www.ubc.ca/okanagan/hse/environment/hazardousmaterials

Radioactive Biohazardous Materials Disposal

• Treat with phenol based biocide• Double bag – calculate storage time and

attach Low Activity Waste (LAW) sheet• Store in freezer and test• Tag as biohazard with red tags• Notify HSE• Remove LAW sheet

High Activity Waste

• Long-lived high activity

• New paint can

– Cloverdale paint

– Home Hardware

• Stock solution vials

• Pipette tips

• Contaminated solids

15. Radiation Emergency Response

IMMEDIATELY notify HSE in the event of any accidental radioisotope release, spill of material or personal contamination.

Contact security for immediate HSE response807-8111 or 78111

Lab Practical Session: *management of small scale spills.

18. Security of Radioactive Material

• Doors shall be closed and locked when lab is unoccupied.

• Only authorized/trained personnel are permitted access to radioactive material/sources: – secondary locked containers as needed

•Missing/damaged/incorrect shipments must be IMMEDIATELY reported to HSE.

•Missing/stolen/misplaced material must be IMMEDIATELY reported to HSE.

•Challenge strangers.

•Keys???

• Professionalism

• Choices

• Integrity

Isotopes and Personal Responsibility

Responsibilities of Licence Holders

• Ensure conditions stated in the licence are fulfilled and safe laboratory practices are followed as per posted signs

• Ensure staff and students using radioactive materials have been authorized to use these radioactive materials.

Responsibilities of Licence Holders

• Ensure staff have received adequate radiation protection training* and have been informed of the risks associated with exposure to ionizing radiation.

*provision of specific training in radioisotope handling in their laboratories.*

• 5 yr training competency requirement.

Responsibilities of Licence Holders

• Ensure that if required, staff have been issued, and wear, a thermoluminescent dosimeter and participate in bioassay programs.

• Designate specific work and storage areas for radioactive materials

– clean, properly labelled, adequate ventilation, adequately shielded.

Responsibilities of Licence Holders

• Maintaining inventories of all purchases, storage, disposal.

• Maintaining all area monitoring and/or wipe test records.

• Reporting all radiation incidents to HSE.

Responsibilities of Radioisotope Users

• Every person…shall…– take all reasonable and necessary

precautions to ensure their own safety and the safety of fellow workers.

– strictly adhere to all policies and procedures defined by the CNSC regulations, WCB Regulations and the University Safety Policy as described in this Manual.

Maryland hits Johns Hopkins with $370,000 fine•For violations of state law relating to use of ionizing radiation and handling of radioactive materials.•Failure to secure radioactive materials from

unauthorised access•Beverages taken into laboratories •Failure to keep radiation measurement equipment in calibration•Failure to label radioactive waste•Failure to conduct surveys for removable contamination

Sound Familiar?

Goiania, Brazil

Goiania Clinic

-

There is a theory which states that if ever anyonediscovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.

There is another theory which states That this has already happened.

D.Adams

Review Questions?• What is the underlying principle behind

handling Low Activity Wastes?

• How should radioactive biological materials be rendered biologically inactive?

• If the specific activity waste limits are met, what else must be met prior to disposal?

Next day• Lab portion 1: Sci 357 1-2 pm

– Appropriate lab attire– Lab coat & safety glasses

• Final Exam: 2-4 pm Sci 3337– 17 M/C– 27 T/F– 20 fill in blanks / short answer– Bring:

• Scientific Calculator