Answers test examination
| # | choice | # | choice | # | choice | # | choice | # | choice |
|---|---|---|---|---|---|---|---|---|---|
| 1 | B | 11 | B | 21 | C | 31 | B | 41 | - |
| 2 | A | 12 | D | 22 | B | 32 | D | 42 | - |
| 3 | C | 13 | C | 23 | D | 33 | D | 43 | C |
| 4 | B | 14 | A | 24 | A | 34 | A | 44 | C |
| 5 | B | 15 | D | 25 | D | 35 | D | 45 | A |
| 6 | B | 16 | A | 26 | C | 36 | A | 46 | C |
| 7 | A | 17 | C | 27 | B | 37 | C | 47 | D |
| 8 | C | 18 | D | 28 | C | 38 | C | 48 | A |
| 9 | D | 19 | B | 29 | A | 39 | C | 49 | C |
| 10 | A | 20 | D | 30 | D | 40 | B | 50 | - |
evaluation question 41:
Activity of droplet = 600 MBq × (0.05 ml / 2 ml) = 600 MBq × 0.025 = 15 MBq
e(50) = e(50)injection = 1.1×10-11 Sv/Bq
E(50) = 1.1×10-11 Sv/Bq × 15×106 Bq = 17×10-5 Sv = 0.17 mSv
Annual limit for nonexposed worker = 1 mSv
–› annual limit is not exceeded
evaluation question 42:
Labeling nonvolatile compound –› p = -2
D-laboratory –› q = 1
Table –› r = 0
e(50) = e(50)inhalation = 8.0×10-10 Sv/Bq
Amax = 0.02×10p+q+r / e(50)inhalation
–› Amax = 0.02×10-2+1+0 / 8.0×10-10 = 2.5 MBq
Load factor
–› B = (4 uur / 40 uur) × (100 kBq / 2.5 MBq) = 0.1 × 0.04 = 0.004
evaluation question 50:
Distance source - surface box = 40 cm / 2 = 20 cm = 0.2 m
Equivalent dose rate at 1 m from 4 GBq = 4000 MBq 137Cs
–› 0.093 μSv·m2·MBq-1·h-1 × 4000 MBq = 370 μSv per hour = 0.37 mSv per hour
Equivalent dose rate at surface box without shielding
–› 0.37 mSv per uur × (1 m / 0.2 m)2 = 9 mSv per hour
Equivalent dose rate on surface box with shielding
–› 0.1 × 9 mSv per hour = 0.9 mSv per hour
evaluation question 51:
Activity = 100 GBq = 100×103 MBq
Time = 10 s = 0.0028 h
Equivalent dose at 1 meter
–› 0.12 μSv·m2·MBq-1·h-1 × 100×103 MBq × 0.0028 h = 34 μSv
Equivalent dose rate at 50 cm = 0.50 m
–› 34 μSv × (1 m / 0.50 m)2 = 140 μSv = 0.14 mSv
Annual limit for exposed A-worker = 20 mSv
Maximal time
–› 0.0028 h × (20 mSv / 0.14 mSv) = 0.4 h = 24 min