Quick Review Flashcards
when do radioactive substances not require a label
container is:
-essential to operation
-will not be used immediately
-small amounts
-used for shipping in accordance with regulations
7 requirements for license to construct
- name and location
- description of machine
- safety features
- occupancy of adjacent areas, workload of machine
- shielding plans
- verification plans
- max dose/dose rate to be received by those commissioning
8 requirements for license to operate
- name and location
- description of machine
- safety features
- occupancy of adjacent areas, workload of machine
- shielding plans
- verification plans
- max dose/dose rate to be received by those commissioning
- proposed commissioning plan
10 requirements for license to decommission
- name and location
- description of machine
- safety features
- occupancy of adjacent areas, workload of machine
- shielding plans
- verification plans
- max dose/dose rate to be received by those commissioning
- proposed commissioning plan
- methods and risks of decommissioning
- planned state of site afterwards
2 requirements for license to service
-equipment and service description
-post QA
concept of justification
no practise will be implemented unless it produces positive net benefit
6 radiation safety records to keep
- radiation survey (3 yrs after license expires)
- daily output
- training documentation
- inspections/servicing required
- documentation of transfer of equipment
- leak test results
4 obligations of licensees plus 4 more for HDR
- sources must be properly labelled and locked down when not in use
- dosimeters must be returned after measurement period
- lost/damaged devices must be reported
- survey meter with battery check must be provided
HDR specific
-equipment: pig, wire cutters, tongs
2. real-type dosimeter for all radiation types with audible warning
3. signage
4. limit public dose to 0.1 mSv/wk and 0.5 mSv/yr
4 obligations of operators in HDR
- QA HDR machine
- survey room after every HDR treatment
- prevent entry to areas > 0.1 mSv/h
- report any dangerous activity
5 radiation safety organization responsibilities
- promote radiation safety
- ensure compliance with safety rules
- monitor exposures
- keep records
- provide info and training
3 groups that may require radiation counselling
-pregnant workers
-individuals expected to exceed dose limits
-people considering volunteering for deliberate exposures as part of research
3 monitoring scenarios
-personnel
-area
-procedure (measure of dose received during particular procedure)
difference between law and regulation
law: any x-ray unit in Canada must have appropriate shielding
regulation: leakage radiation must be less than X
license for deuterium/uranium/thorium?
can do what you want as long as < 10 kg/calendar yr
what to do with tritium-activated self-luminous safety sign?
can do wtv you want as long as:
-no other nuc substances
-no more than 925 GBq of gaseous tritium
-light emitting part is enclosed such that it can’t be removed
-amt of tritium in form of oxide < 1%/volume for each glass tube
-don’t have > 10 of them
what to do with check source
can do wtv you want as long as:
-< 370 kBq, no alpha
-< 3.7 kBq, Z> 81 and gives off alpha
-no direct contact
-proper marking
supervisors of trainees
must always be present
replacement of sealed source: measurements
-dose rate on each surface of device
-dose received by people exposed during change
trace studies
-contact CNSC if using > 2 GBq of nuc not sealed
-within 60 days file report with CNSC
keeping reports of leak tests
-keep them for period ending 3 years after the date on which it is conducted
woman’s position if imaging the fetus
use prone position
4 ways to minimize patient dose during xray exam
-use air gap between patient and image receptor
-use optimum focal spot to image receptor distance
-use highest xray tube voltage which produces good quality image
-use AEC to keep irradiations and repeats to a min
entrance surface dose (mGy) for different studies
- Chest (PA)- 0.2-0.3
- Chest (LAT)- 0.7-1.5
- thoracic spine (AP) - 5-8
- thoracic spine (LAT) - 7-10
- Lumbar spine (AP) 7-10
- Lumbar spine (LAT) 15-30
- Abdomen (AP) 7-15
- Pelvis (AP) 5-10
- Skull (AP) 4-5
- Skull (LAT) 2-3
Abdominal radioscopy dose area product
20-70 Gy cm2
barium enema dose area product
30-60 Gy cm2
coronary angiography dose area product
35-75 Gy cm2
CTDIw and DLP head
60 mGy
930-1300 mGy cm
CTDIw and DLP face and sinuses
35 mGy
360 mGycm
CTDIw and DLP chest
30 mGy
580-650 mGycm
CTDIw and DLP abdomen- pelvis
35 mGy
560-1100 mGycm
CTDIw and DLP spleen
35 mGy
470-920 mGycm
chest entrance dose for child
0.05-0.15 mGy AP
0.15-0.25 mGy LAT
abdomen entrance dose for child
0.5-1 mGy
AP
pelvis entrance dose for child
0.6-1 mGy
AP
skull entrance dose for child
1-2 mGy AP
0.8-1.5 mGy LAT
procedure for receiving radioactive packages
-inspect for damage/leaking
-wear lab coat and gloves, place package in fume hood
-monitor radiation outside package and compared with units on label
-wipe test exterior
-open, remove inner packaging
-avoid direct contact with unshielded containers
-verify details (isotope, activity), log info
-report anomalies
photodisintegration
-gamma is absorbed by atomic nucleus and nucleaus emits a subatomic particle (proton, neutron, or alpha)
-endothermic for nuclei lighter than iron and sometimes exothermic for nuclei heavier than iron
classical electron radius
(1/(4pi epsilon knot) )* e^2/(mc^2) = 2,8 *10^-15 m
radius of bohr atom
-most probably distance between proton and electron in hydrogen atom in ground state
5.3 *10^-11 m
