RADIATION SAFETY T RAINING. Presented by: Ali Shoushtarian Office of Risk Management, Environmental Health and Safety Service. Last revised Jan. 2009. Manager, Radiation and Biosafety Lois SowdenPlunkett ext. 3058 [email protected] Compliance Inspector
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Presented by:Ali Shoushtarian
Office of Risk Management, Environmental Health and Safety Service
Last revised Jan. 2009
Manager, Radiation and Biosafety
Lois SowdenPlunkett
ext. 3058 [email protected]
Compliance Inspector
Ali Shoushtarian
ext. 3057 [email protected]
Radiation Safety Program Web Page http://www.uottawa.ca/services/ehss/ionizing.htm
Reports to the Board of Governors
Chaired by ViceRector, Research
Ensures compliance with CNSC regulations and license conditions, issues permits
Office of Risk Management – EHS
Manages the radiation safety program
Conducts inspections
Monitors doses, inventory
Conducts training
STAKEHOLDERS
Radioisotope Permit Holder
Radioisotope User
1. Open Sources
2. Sealed Sources
3. Sealed Sources incorporated in a device
4. Exempt Quantities
with associated permit conditions
GENERAL INTRODUCTION
physical and biological characteristics
risk analysis
units and calculations
OPERATIONAL PROCEDURES
ordering and receipt of material
inventory and disposal
monitoring
SAFE PRACTICES
personal protection
handling procedures
laboratory safety
MOVIE
WHAT IS RADIATION ?
Excess p & n alpha particles
Excess p positron ( + )
Excess n negatron (  )
Excess nuclear E gamma ray
Excess orbital E Xray
POSITRON (similar to an electron but positive charge)
IONIZATION
EXCITATION
INTERACTION WITH MATTER
vital cell structures
INDIRECT
ionizes H2O
forms peroxides
interacts with the vital cell structure
INTERACTION WITH BIOLOGICAL MATTER(average linear dimension of a cell = 17.1 m )
At low doses, the effects of radiation are not known.
PREGNANCY
Whole body, gonads, 1 mSv 50 mSv
bone marrow
Skin, thyroid, bone 50 mSv 500 mSv
Tissue of hands, feet, 50 mSv 500 mSv
and forearms
Dose Limits:THERMOLUMINESCENT DOSIMETRY
Non  S.I.(Système international)
CURIE (Ci)
1 Ci = 3.7 x 1010 dps
S.I.
BECQUEREL (Bq)
1 Bq = 1 dps
Non  S.I.
RAD (rad)
1 rad = 100 ergs of energy/g
S.I.
GRAY (Gy)
1 Gy = 1 joule of energy/kg
Non  S.I.
REM (rem)
1 rem = rad x Quality Factor
S.I.
SIEVERT (Sv)
1 Sv = Gy x Quality Factor
A = Aoe  t
A = activity at time “t”
Ao= activity at time zero
t = elapsed time
= decay constant ( = 0.693 / t 1/2)
? Does another order of 35S have to be placed or is there enough remaining activity that the experiment may proceed?
A = A0e  t
A = activity at time ‘t’ ( ? )
A0= activity at time zero (250  100 = 150 Ci)
t = elapsed time (42 days)
= decay constant (0.693 / 87 days = 0.00797)
A = (150)e  (0.00797)(42)
A = 107.32 Ci
(** SAVINGS **)
Step 1 Determine counting
efficiency of the detector.
Step 2 Convert cpm to dpm.
Step 3 Convert dpm to Curie.
% efficiency = observed cpm  background cpm x 100 source of emission rate (dpm)
Ex. count rate = 2045 cpm
background = 65 cpm
source = 220 Bq = 1.32 x 104 dpm
% efficiency = 2045  65 cpm = 15%
1.32 x 104 dpm
dpm = corrected cpm
efficiency
Ex. Sample = 4925 cpm
background = 65 cpm
efficiency = 15%
dpm = 4925  65 = 32,400
0.15
Since 1 Bq = 1 dps = 2.7 x 1011 Ci
Then 60 dpm = 2.7 x 1011 Ci
Therefore32,400 dpm = 1.48 x 108 Ci
or, # Bq = __1.48 x 108 Ci_ = 540 Bq
2.7 x 10 11 Ci/Bq
Annual Limit on Intake (ALI)
The activity, in Becquerel (Bq), of a radionuclide that will deliver an effective dose of 20 mSv after the radionuclide is taken into the body
Basic: 5 X ALI Intermediate: 550 X ALI High: 50500 X ALI
Exemption Quantity (EQ)
The quantity, in Becquerel (Bq), of a radionuclide, below which no licence is required
10000 EQ: Written approval from CNSC
Class A (high): Na22, Zn65
Class B (med): Rb86
Class C (low): H3, C14 , S35, Ca45,
P33, P32, I125
 Radioisotopes Purchase Requisition form
 Form must be complete (PO number, signature)
 EHSS approval before ordering
 Documentation (packing slips, shipper’s declaration)
 Definition of radioactive materials
 Radioactive packages
 Radiation warning labels
 Receipt of radioactive material
DEFINITION OF RADIOACTIVE MATERIAL FOR TRANSPORT
Former:
 70kBq/kg
New:
 radionuclide dependent
 types of radiation
 energies
 chemical forms
 potentialbiological effect on persons
Radioactive packages may be shipped as:
 Excepted packages
 Industrial packages – Categories I, II and III
 Type A packages – lower amounts
 Type B (U) packages – large amounts; ≤ 700 kPa
 Type B (M) packages – large amounts; > 700 kPa
 Type C packages – for air transport of high activity
EXCEPTED PACKAGES
 The safety mark ‘RADIOACTIVE’ must be visible on
opening the package
 The radiation level at any point on the external surface
of the package must not exceed 5 Sv/h
All other packages must be categorized by radiation
level and display the corresponding radiation warning
labels as follows:
RADIATION WARNING LABELS
Category IWhite: less than 5 Sv/h
Category IIYellow: less than 500 Sv/h, TI less than 1
Category IIIYellow: less than 2 mSv/h, TI less than 10
TI: maximum radiation level in Sv/h at 1 meter from the
external surface of the package, divided by 10.
Ex: 1 Sv/h (0.1 mrem/h) at 1 m equals a TI = 0.1
RECEIPT OF RADIOACTIVE MATERIAL
 Radioactive packages must be delivered to the laboratory using a cart
to increase distance between the transporter and the package in order
to minimize radiation exposure
 Inspect packaging both externally and internally for damage or leakage
 Perform contamination monitoring on the package, vial holder and vial
 Deface wording and labels prior to disposal of the package
 Complete an Inventory of Use and Disposition form
Report any anomalies to the supervisor and RSO
(encapsulated, incorporated in a
device, check sources)
** HISTORICAL
Landfill
ShortTerm Storage
OffSite
(1 DL / kg)
(t 1/2 = 90 days)
Disposal
(e.g., sealed sources)
(1 DL/kg)
DISPOSAL
DISPOSAL LIMITS (DL) TO MUNICIPAL GARBAGE
C14: 3.7 MBq (100 μCi)/kg; H3: 37 MBq (1000 μCi)/kg
I125: 0.037 MBq (1 μCi)/kg; P32: 0.37 MBq (10 μCi)/kg
Time required for decay
A = Ao e  t
t = ln (A/Ao)

A = activity at time ‘t’
Ao= activity at time zero
t = elapsed time
= decay constant ( = 0.693 / t 1/2 )
t = ln (A/Ao)

A = activity at time ‘t’ (7.85 Ci)
Ao = activity at time zero (100 Ci)
t = elapsed time (?)
= decay constant (0.693 / 14.3 days = 0.0485/day)
t = ln (7.85 Ci / 100 Ci) = 52.5 days
 0.0485/day
* prior to repair of equipment
Contamination Monitoring (Open Sources)
Contamination Criteria <
Class A: 3.0 Bq/cm2
Class B: 30 Bq/cm2
Class C: 300 Bq/cm2
Decommissioning Criteria <
Class A: 0.3 Bq/cm2
Class B: 3.0 Bq/cm2
Class C: 30 Bq/cm2
EHSS Criteria
0.3 Bq/cm2
Parameters of interest for contamination monitorsEfficiency
Not all decay emissions
Are detected!
Detector Covering
Detector Volume
Efficiency:
1) Distance: 1/r2
2) Beta Absorption
3) Size of window
Surface
Converting cpm results into Bq/cm2 for GM pancake
1. General Condition of lab
2. Inventory/Disposal
3. Contamination Monitoring
4. Measurements
5. Questionnaire
Inverse Square Law
D1 s12 = D2 s22
D1 = dose at distance 1
s1 = distance 1
D2 = dose at distance 2
s 2 = distance 2
 energy of radiation
 type of shielding
remember: 4 geometry
Inform coworkers & supervisor.
Inform Protection Services (5411)
Inform ORM
(3058, 3057)
1. Attend to injured person and ensure personal safety.
2. Assess the size of the spill.
3. Obtain necessary supplies.
4. Cover spill with absorbent.
5. Push spill towards centre.
6. Decontaminate area in sections.
7. Check for contamination (record).
8. Reclean as necessary.
9. Inform Radiation Safety Officer of fixed contamination.
Unopened
Opened
Contents not intact (spilled)
External Dose: time distance shielding
Internal Dose: critical organs
prevent: …. ingestion
…….absorption
…….inhalation