1. The half-life of
Po-210 is 138.4 days. An anti-static plate is obtained with an activity of 300 µCi. What
is the activity 3 years later?
An alternative method of calculating the answer is to calculate the
number of half lives that have passed and used  .
2. A source has an intensity of 500 mr/hr at 6 feet. What is the intensity at 50 feet?
I2
I1
|
= |
[ |
d1
d2 |
] |
2 |
I1 = 500 d1 =
6 d2 = 50 |
|
3. The half-value layer for a shielding material is 5 mm. If the
intensity of the radiation beam striking the shield is 100 R/hr and the shield is 2 inches
thick, what is the intensity is mR/hr on the other side of the shield?
|
|
4. Calculate the absorbed dose
rate produced in bone (f = 0.922) by 1 MeV gamma radiation which produced an exposure rate
of 0.5 mR/hr.
5. Calculate the absorbed dose rate in soft tissue (f = 0.965) for
the condition in problem 4.
 |
|
|
Back to Top
www.osha.gov
