What is an example of a secondary barrier?

A secondary barrier is a structural feature designed to reduce radiation exposure to personnel and the public by providing additional protection beyond the primary barrier. The correct choice involves an example of a physical layer that aids in this purpose.

Choosing a disposable surface on a workbench to set tools on, while it may apply to cleanliness or organization, does not serve the protective function associated with radiation shielding. It does not inherently reduce radiation exposure, which is the primary requirement for a secondary barrier.

In contrast, engineered ventilation refers to systems designed to control airborne contaminants, including radioactive particles, but it serves more as a control measure rather than a physical barrier to radiation.

Maintaining programs to keep exposure As Low As Reasonably Achievable (ALARA) is an important operational philosophy but does not constitute a physical barrier to radiation.

The term SWIMS typically relates to specific programs or methods in radiation protection and does not directly describe a physical barrier.

Thus, the correct answer should represent a physical structure designed to shield against radiation exposure, reflecting the defined characteristics of secondary barriers in radiation safety.