Gross external survey is conducted as time permits to locate and mark the boundaries of contaminated areas.

• A. Gross external survey
• B. Rapid external survey
• C. On-station monitoring
• D. Periodic monitoring

Answer: (A)

In contamination control, surveys are chosen by how quickly you need results and how detailed the mapping should be. The phrase describes a slower, deliberate pass whose purpose is to locate exactly where contamination exists and to mark the boundary lines for controlled zones. That precise boundary-mapping, done as time permits, matches the gross external survey.

A rapid external survey would be the quick pass used when time is tight to identify obvious hotspots, not to lay out complete boundaries. On-station monitoring and periodic monitoring refer to ongoing or repeated checks during operations, not the initial boundary-delineation effort described here.