United States Nuclear Regulatory Commission - Protecting People and the Environment

Intrusion Alarm Assessment

Intrusion detection systems can incorrectly alarm because of environmental or other factors; therefore, the licensee must assess whether an alarm is genuine or not. The assessment also provides information to the security force about the number, location, and weapons of the intruders.

Intrusion Alarm Assessment can be performed in a number of ways, including use of:

  • Closed circuit televison (CCTV) cameras to observe the zone of the alarm
    • CCTV performance can be enhanced by use of video capture systems to allow instant play-back of the scene at the time the alarm was tripped
  • Security officers in guard towers
  • Security officers proceeding to the alarm zone

Intrusion Alarm Assessment performance should be adequate to correctly identify actual intrusions despite adversary use of such techniques as:

  • speed of individuals through the isolation zone
  • camouflage of persons in the isolation zone
  • shadows or other lighting conditions in the isolation zone
  • alarm stacking, that is, causing a large number of alarms over a short period of time
  • normal environmental factors affecting visibility
Page Last Reviewed/Updated Wednesday, November 06, 2013