Methods of Minimizing External Dose - doe-hdbk-1106-97

DOE-HDBK-1106-97

4.0

Methods of Minimizing External Dose

4.1 Distance

Maintain the greatest distance possible between the worker and the gamma-

emitting animal to make full use of the inverse square law. This law, simply stated,

implies that if the distance from a radioactive source is doubled, the dose is reduced

by a factor of four.

4.2

Time

When the distance cannot be minimized, the amount of time spent in the proximity

of the radioactive animal should be kept at a minimum.

4.3

Shielding

When the above is not possible for any reason or when the dose rate is determined

to be very high, lead shielding of the proper thickness should be placed between the

worker and animal. This is a clumsy technique and should only be attempted

following consultation with a health physicist.

4.4

Source Reduction

Following the experiment and/or the death the animal, proper waste disposal

proceedings should be initiated.

5.0

Methods of Minimizing Internal Dose

When handling radioactive animals or applying radionuclides to animals, it is required

that the handler wear gloves that can be thrown away when contaminated. This will

prevent the transfer of radionuclides from hand to mouth and is equally important when

handling excreta or animal parts that may be radioactive.

Procedures for handling of the animal should be implemented to reduce the possibility of

animal bites. This would include such activities as sedation of the animal in some

procedures and special handling techniques for specific animals in other procedures. Both

the researcher and the animal handler should be trained in these procedures.