Methods for maximizing distance from sources of radiation

DOE-HDBK-1130-98

Module 4: ALARA Program

Instructor's Notes

Do not exceed stay times. In some cases, the

Radiological Control Organization may limit

the amount of time a worker may stay in an

area due to various reasons. This is known

as "stay time." If you have been assigned a

stay time, do not exceed this time.

10)

(Insert facility-specific information.)

b. Methods for maximizing distance from sources of

EO4 Identify methods for

radiation

reducing external and

internal radiation dose.

The worker should stay as far away as possible

from the source of radiation.

1) Stay as far away from radiation sources as

Dose RateA=

practical given the task assignment. For point

Dose RateB x Distance A

sources (such as valves and hot spots), the dose

Distance2B

rate follows a principle called the inverse square

law. This law states that if you double the

distance, the dose rate falls to 1/4 of the original

dose rate. If you triple the distance, the dose

rate falls to 1/9 of the original dose rate.

2) Be familiar with radiological conditions in the

area.

3) During work delays, move to lower dose rate

areas.

4) Use remote handling devices when possible.

5) (Insert facility-specific information.)

c. Proper uses of shielding

Shielding reduces the amount of radiation dose to

EO4 Identify methods for

the worker. Different materials shield a worker

reducing external and

from the different types of radiation.

internal radiation dose.

1) Take advantage of permanent shielding, such as

non-radiological equipment/structures.

2) Use shielded containments when available.