Under what condition can a federal facility close its doors to the public during business hours?

A federal facility can close its doors to the public during business hours when the Occupant Emergency Plan requires it. This plan is developed to ensure the safety and security of occupants in case of various emergencies, such as natural disasters, threats, or other critical incidents that could pose risks to individuals within the facility. The emergency plan outlines the protocols for securing the building, which may include restricting access to safeguard both personnel and visitors during potentially hazardous situations.

In contrast, the other options do not provide valid justifications for closing a facility during business hours. Closing at the request of a visitor does not align with operational protocols, as decisions to restrict public access are typically based on safety and security considerations rather than individual requests. Federal holidays are designated times when federal offices may be closed, but they do not influence day-to-day operations regarding public access under normal circumstances. Lastly, while maintenance is necessary for the upkeep of a federal facility, routine maintenance does not constitute a condition warranting closure unless it specifically impacts safety or operation as outlined in the applicable policies.