Accountancy System: A quantitative system that gives information on the nuclear materials and amount of materials a facility has. More.

Adversary: Any individual performing or attempting to perform a malicious act. More.

Adversary Sequence Diagram (ASD): A means of graphically displaying paths that an adversary might take to accomplish his or her objective. More.

Adversary Task: A required goal in order for the adversary to continue along their path; such as getting inside the facility or past a door. More.

Baiting: Baiting involves dangling something you want to entice you to take an action the criminal desires. More.

Collusion: Secret agreement or cooperation especially for an illegal or deceitful purpose. More.

Compartmentalization: A management technique in which different groups are kept separate to limit to possibility of personnel leaking information. More.

Criminal Act : An act that is against State, National or International law/regulations. More.

Critical Detection Point (CDP) : The final opportunity of detection for a facility against an adversary, before the adversary's path would go undetected. More.

Defeat : To stop the adversary from accomplishing their goal; to overcome a contest; to eliminate a threat. More.

Defense in Depth : The combination of multiple layers of systems and measures that have to be overcome or circumvented before nuclear security is compromised. More.

Delay: To slow or hinder the progress of a threat. More.

Delay Barriers : Walls, fences or other ways of blocking an adversary's path and causing them to take more time to get further along their path than intended. More.

Detection : Determining that an unauthorized action has occurred or is occurring. More.

Highly Enriched Uranium (HEU) : Highly enriched uranium (HEU) has a 20% or higher concentration of 235U. More.

Insider: One or more individuals with authorized access to associated facilities or associated activities or to sensitive information or sensitive information assets, or one or more individuals with nuclear security responsibilities who could commit a malicious act or who could aid an external threat to do so. More.

Malicious Act : An act indended is to cause damage or harm to persons or property. More.

MICE: An acronym for Money, Ideology, Coercion, and Ego, the primary motivations for insiders to commit malicious acts. More.

Mole: a mole is an individual who works for one organization, while covertly working for a separate organization. More.

Most Vulnerable Path (MVP) : The path that gives an adversary the best chance of penetration. More.

Outsider : An adversary other than an insider. More.

Phishing: A way of acquiring useful information such as passwords or usernames, through the use of pop-ups, emails or others social engineering functions that are made to look like a trustworthy source. More.

Physical Protection System (PPS) : An integrated set of physical protection measures intended to prevent the completion of a malicious act. More.

Preventative Measures : Parts of a facility that are implemented in order to stop adversaries from performing criminal acts. More.

Probability of Detection : The mathematical likelihood that an adversary will be detected within an area of a facility by the protection and surveillance system in place there. More.

Protection Measure : The personnel, procedures, and equipment that constitute a physical protection system. More.

Response Force : Persons, on-site or off-site, who are armed and appropriately equipped and trained to counter an attempted unauthorized removal of nuclear material or an act of sabotage. More.

Social Engineering : A way of gathering information that requires human interaction and their manipulation into obtaining the data needed. More.

Tailgating : A way of gaining access into a building without proper authorization, done by following someone with proper authorization inside. More.

Target: Nuclear material, other radioactive material, associated facilities, associated activities, or other locations or objects of potential exploitation by a nuclear security threat. More.

Threat : A person or group of persons with motivation, intention and capability to commit a malicious act. This is synonymous with nuclear security threat. More.