Miscellaneous Flashcards
for a population exposed to uniform whole body dose, genetic defects contribute what % to total detriment?
8% because wt = 0.08
LD50
4 Gy without medical intervention
lethal uniform whole body dose
5 Gy
dose for temporary epilation
3-5 Gy
>7 Gy is permanent
skin dose effects and ranges
2-5 Gy erytherma
5-10 Gy erythema, atrophy
10-15 Gy moist desquamation
> 15 Gy ulceration, edema, need surgery
effect of fractionation on sterility in males
fractionation make sterility worse
dose for permanent sterility
6 Gy males
10 Gy pre-pubescent females, 2 Gy pre-menopausal women
risk of cancer for someone not exposed to radiation
30-50%
risk of congenital malformation for someone not exposed to radiation
5%
doubling dose
1 Gy
sensitivity of newbors vs elders
newborns 3 x more sensitive than 25 yo and elders 3x less
ICRP hereditary risks
0.1%/Sv working pop.
0.2%/Sv whole population
how to calculate effective dose to worker from dosimeter
0.18 H collar
or
1.5Hwaist + 0.04 Hcollar
typical dose received by radiation worker
2-5 mSv/y
NCRP lifetime effective dose limit
10x age
how much Pb lines xray rooms?
1.6 mm
skin limit for workers
500 mSv over highest exposed 1 cm2 area
Pb apron thickness
0.25-0.5 mm
ICRP cancer risk value
5.5%/sV for all
4.1%/Sv for adults
then heritable effects are 0.2 and 0.1%/Sv, leaving total detriment at 5.7 and 4.2 %
dose limit for students and techs training on DI equipment
1 mSv/y
max leakage radiation from xray tube
1 mGy/h at 1 m from focal spot
how long does a licensee have to inform the commission of someone representing the RSO for example or other changes in representation?
15 days before the change occurs
prescribed limit for contamination
ny quantity of a radioactive nuclear substance
that may, based on the circumstances, increase a person’s effective dose by 1 mSv or more per year in excess
of the background radiation for the place or vehicle
how long do you keep record of CNSC license?
-as specified in applicable regulations made under the Act, or
-one year after expiry of license
when can someone dispose of a CNSC record?
-if no longer required to keep it by the Act
OR
-notify commission of date of disposal and conditions at least 90 days before disposal
how long do you have to file report to the commission?
-preliminary report right away
-full report 21 days after becoming aware
what is the date of filing of a report?
date it is received by commission
security levels
categories I to 5
To assign a category, the total activity of all sources in one facility (storage or use) where sources are in close proximity must be equal to, or greater than, the number identified in the category. For example:
a teletherapy medical device with a sealed source up to 555 TBq of cobalt-60 is a Category 1 source (555 > 30) a certified radiography exposure device with a sealed source of 2.5 TBq of iridium-192 is a Category 2 sealed source (80 > 2.5 > 0.8) a high dose rate (HDR) brachytherapy medical device with a sealed source up to 0.44 TBq of iridium-192 is a Category 3 source (0.8 > 0.44 > 0.08)
For security control purposes, the aggregation of sources in a single storage (or use) facility can be used to determine a security category. This is done by adding the actual sealed source activities of the sources and determining the category from Table 1. For example, one industrial level gauge containing a sealed source with 0.19 TBq of cesium-137 is a Category 3 source (1.0 > 0.19 > 0.1). However, when there are six of these sealed sources at a single licensed location, for security reasons they may be treated as a Category 2 source (6 x 0.19 = 1.1 > 1.0).
Safety code 35 annual limit
20 mSv/year
IDR outside of nuc med room
< 2.5 uSv/h
shielding for electrons only
just concrete
can’t have Pb would create issue
has to be low Z
lifetime dose limit for ICRP vs NCRP
ICRP 1 Sv
NCRP 10 mSv times age
density of concrete
2.2- 2.4 g/cm3
heavy is 4.81 g/cm3
