Management of Radioactive Waste
Disposal Procedures

• Decay
• Dilution
• Landfill

• Decay Considerations
– Half-life
– Energy/ Shielding
– Storage/decay space

Gases
Radioactive
Waste
Disposal
Liquids Solids

Fumes Gases
Dusts Vapors
Release Limit is Set for each isotope by CNSC
See Table 5 in the Manual for details

• Aqueous
• Organic – includes ALL scintillation cocktails
• Aqueous Organic Biodegradable

Tritium
Carbon-14
Sulphur-35
370 kBq/l
37 kBq/l
3.7 kBq/l
Phosphorous-32 3.7 kBq/l
Phosphorous-33 3.7 kBq/l
Chromium-51
Iodine-125
3.7 kBq/l
0.37 kBq/l

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

• How much C-14 is allowed in one container?
C-14 Release Limit =37 kBq/l
Container volume = 5 litres
R.L. x Volume=Activity limit per container
37 kBq/l x 5 litres= 185 kBq

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 scintillation waste periodically.
Separate ‘hot’ cocktail samples if limits for disposal are approached.

• How to dispose 46 MBq of C-14 in nontoxic 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
OUT
Diluted waste
Water
IN
Hot solution
Contact HSE before considering using this method dispose of waste … to

Follow release limit
AND
2.5 
Sv/h at the surface

WASTE Disposal - Solid
Tritium
Carbon-14
3700 kBq/kg
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

Decay time for 9.25 MBq of P-32 in 1.0 kg?
ln
N f
N o x
T
1/2
= T
-0.693
N o
=
N f
=
T
1/2
=14.3 days
Thus T= www.ubc.ca/okanagan/hse/safety/radiosotope.html

SOLID WASTE – Low Activity
• As waste is generated, deface all radiation warning labels and place into lined radioactive waste container - Lid and Label
•When full - complete and attach Low Activity
Waste (LAW) label and place bag in decay storage area
- note disposal date on calendar
(TABLE 5 in Manual)

Caution Radioactive Material
Low Activity Waste for Decay
Permit Holder(PI)/Lab ________________
Waste Generator Name _______________
Lab Contact Phone # _______________
RADIOISOTOPE : ________
Activity to decay ______MBq
(FROM YOUR RADIOISOTOPE DATASHEET)
Survey meter reading at surface of box ____ uSv/hr
Box #___
Initial Date _____________
Disposal Date _____________
Actual Date of Disposal ____________
Disposed by _____________________
REMOVE THIS SHEET ON DISPOSAL DATE AND SAVE WITH YOUR
RECORDS. COMPLETE YOUR ANNUAL INVENTORY WITH DISPOSAL
INFORMATION

-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

• 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

•
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 response
807-8111 or 78111
Lab Practical Session:
*management of small scale spills .

• 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

• 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 .

• 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.

• 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.

• Maintaining inventories of all purchases, storage, disposal.
• Maintaining all area monitoring and/or wipe test records.
• Reporting all radiation incidents to HSE.

• 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 anyone discovers 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
-

• 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?

• 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