Radiation Safety

Question 1

The current regulation for radionuclide therapy patients state that such patients can be released from the hospital when the projected dose to individuals around the patient is less than or equal to _______.

Answer 1

5 mSv (or 500 mrem)

Question 2

During the most sensitive period of pregnancy relating to the central nervous system, the decline in IQ has been estimated to be about 30 IQ points per what fetal exposure dose to ionizing radiation?

Answer 2

1 Gy

Question 3

As a rule of thumb, the exposure from scattered radiation is what fraction of the entrace skin exposure at 1 m away from the patient?

Answer 3

1/1000

Question 4

What publication details shielding calculations and recommendations for x-ray units?

Answer 4

NCRP Report 147

Question 5

What is the occupancy factor in shielding calculations?

Answer 5

The expected fraction that the maximally exposed person will be in a certain room

Question 6

What is the occupancy factor behind a door?

Answer 6

1/8

Question 7

What is the occupancy factor for an office?

Answer 7

1

Question 8

What is the occupancy factor for a corridor?

Answer 8

1/5

Question 9

The target effective dose rate for shielding an uncontrolled space is ______ mSv / week.

Answer 9

0.02

** Note: Since the annual limit is 1 mSv per year, divide by 50 weeks per year

Question 10

What is the criteria for if a person is a designated radiation worker or if they should have a personal dosimeter?

Answer 10

If their expected radiation exposure exceeds 10% of the annual limit (50 mSv / year)

Question 11

What is the increased rate of fatal cancer from radiation exposure?

Answer 11

5% per Sievert