Transcript Waste Disposal & Emergency Response

Management of Radioactive Waste
Disposal Procedures
Waste Handling
• Decay
• Dilution
• Landfill
• Decay Considerations
– Half-life
– Energy/ Shielding
– Storage/decay space
Radioactive
Waste
Disposal
Gases
Liquids
Solids
Gaseous Waste
Fumes Gases
Dusts 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
Carbon-14
Sulphur-35
Phosphorous-32
Phosphorous-33
Chromium-51
Iodine-125
370 kBq/l
37 kBq/l
3.7 kBq/l
3.7 kBq/l
3.7 kBq/l
3.7 kBq/l
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?
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.
Dilution – Not Recommended
• 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
Contact HSE before
considering
using
this
method
to
dispose of waste…
Diluted
waste
Water
OUT
Water
IN
Hot
solution
Solid Waste –
Low Activity
• Decay
• Landfill
Follow release limit
AND
2.5 Sv/h at the surface
WASTE Disposal - Solid
Tritium
Carbon-14
Sulphur-35
Phosphorous-32
Phosphorous-33
Chromium-51
Iodine-125
3700 kBq/kg
370 kBq/kg
37 kBq/kg
37 kBq/kg
37 kBq/kg
37 kBq/kg
3.7 kBq/kg
And less than 2.5 Sv/hr at
the surface
Timed Disposal
Decay time for 9.25 MBq of P-32 in 1.0 kg?
ln
Nf
No
x
T1/2 = T
-0.693
No=
Nf=
T1/2 =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
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 response
807-8111 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???
Isotopes and Personal
Responsibility
• Professionalism
• Choices
• Integrity
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 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
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