Reducing External Dose (Key Item)

DOE-HDBK-1109-97

Radiological Safety Training for Radiation-Producing (X-Ray) Devices

Instructor=s Guide

Lesson Plan

Instructor=s Notes

ALARA

Objective 5

Because the effects of chronic doses of low levels of

ionizing radiation are not precisely known, we assume

there is some risk for any dose. The ALARA principle

is to keep radiation dose as low as reasonably

achievable, considering economic and social

constraints.

The goal of an ALARA Program is to keep radiation

dose as far below the occupational dose limits and

administrative control levels as is reasonably

achievable. The success of an ALARA Program is

directly linked to a clear understanding and following

of the policies and procedures for the protection of

workers. Keeping radiation dose ALARA is the

responsibility of all workers, management, and the

radiation-protection organization.

REDUCING EXTERNAL DOSE (KEY ITEM)

Objective 5

Three basic ways to reduce external doses are to

Discuss facility-specific methods

to reduce external dose.

Minimize time.

Maximize distance.

Use shielding.

Minimize time near a source of radiation by planning

ahead. Increase distance by moving away from the

source of radiation whenever possible. The dose from

X-ray sources is inversely proportional to the square of

the distance. This is called the inverse square law, that

is, when the distance is doubled, the dose is