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Nuclear Safeguards Education Portal

Physical Protection Systems

Description: This section presents a number of terms related to the physical protection of nuclear materials and facilities. The definitions and information found in this chapter are largely taken from the following sources:

  1. IAEA Safeguards Glossary: 2001 Edition (PDF)
  2. Garcia, Mary Lynn. The Design and Evaluation of Physical Protection Systems. Amsterdam: Elsevier/Butterworth-Heinemann, 2008.
  3. IAEA, The Physical Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Rev.4).
  4. Radiation Emergency Medical Management (REMM), US Department of Health and Human Services, Dictionary of Radiation Terms.

Acceptance testing: performance of all necessary testing to demonstrate that installed equipment will operate satisfactorily and safely in accordance with the design plans and specifications More.
Access control: In the fields of physical security and information security, access control is the selective restriction of access to a place or other resource. More.
Activated Delay: The element of a physical protection system designed to increase adversary penetration time for entry into and/or exit from the nuclear facility or transport and is based on a sensor to be initiated. More.
Activated Denial: The element of a physical protection system designed to deny an adversary entry into and/or exit from the nuclear facility or transport and is based on a sensor to be initiated. More.
Adversary: Any individual performing or attempting to perform a malicious act. More.
Adversary Action Sequence: A require/ordered series of acts performed by an adversary to achieve their objectives. More.
Adversary class: Adversaries can be generalized into two categories as insiders or outsiders. Insiders work from within the facility and outsiders do not. More.
Adversary neutralization: When an adversary is captured, killed, or forced to leave by response forces and the threat is terminated. More.
Adversary path: The required steps and actions that an adversary must perform in order for a successful completion of their goal. More.
Adversary Sequence Diagram (ASD): A means of graphically displaying paths that an adversary might take to accomplish his or her objective. More.
Adversary sequence modeling: The use of an analytical model to estimate the statistical success of an adversary through a given set of steps or actions. 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.
Alarm assessment: Determining whether an alarms status is genuine or not. More.
Alarm Communication and Display (AC&D): A subsystem that transports alarm and video information to a central location for human processing. More.
Alternate access points: Other ways or entrances that a person could arrive through other than the main entrance and exits. More.
Assessment: The determination by a guard or an electronic system of the cause of an alarm and the extent of the threat More.
Automated access control system: A system to authorize personnel, vehicles or materials to move through a checkpoint into a secured area. More.
Central Alarm Station: An installation which provides for the complete and continuous alarm monitoring, assessment and communication with guards, facility management and response forces. More.
Contraband: Materials such as firearms, explosives, or special nuclear material that are not permitted to enter or to leave a particular area; unauthorized material or material that could be used for sabotage, such as special nuclear material (SNM), shielded SNM, weapons, explosives, narcotics, gold, and/or currency. More.
DDDRR of Security Risk: An acronym for Deterrence, Detection, Delay, Response, and Recovery. More.
Deceit: The act or practice of deceiving; concealment or distortion of the truth for the purpose of misleading; duplicity; fraud; cheating. 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.
Denial: A step that disallows the threat to gain access or use a particular location. More.
Deployment: The actions of the protective force from the time communication is received until the force is in position to neutralize the enemy. More.
Design and Evaluation Process Outline (DEPO): The Design and Evaluation Process Outline (DEPO) is a methodology developed by Sandia National Laboratory that is used in the design and evaluation of physical protection systems. More.
Design Basis Threat (DBT): The attributes and characteristics of potential insider and/or external adversaries, who might attempt unauthorized removal of nuclear material or sabotage, against which a physical protection system is designed and evaluated. More.
Detection: Determining that an unauthorized action has occurred or is occurring. More.
Deterrence: An act that discourages the adversary from attempting to continue with their plan. More.
Diversion: An attack, or feint, that draws the attention and force of an enemy from the point of the principal operation. More.
Entry control: The equipment that is used to authorize entry and detect contraband entering or exiting the facility. More.
Event: An act against a physical protection system that an adversary must perform to achieve his or her objective. More.
Facility Characterization: Describing, listing, or drawing the major parts of a facility. More.
False Alarms: An alarm found by subsequent assessment not to have been caused by the presence of nuclear or radioactive material. More.
Force: An overt attempt to overcome a security system by violence, compulsion, or constraint. More.
Guards: A person who is entrusted with responsibility for patrolling, monitoring, assessing, escorting individuals or transport, controlling access and/or providing initial response. More.
IAEA Categorization of Nuclear Material: A table for different types of nuclear materials, their form as well as the category that each weight would fall under. More.
Impostor pass rate: The rate at which an adversary with a false identity and credentials are allowed to proceed through an entry check-point. More.
Improvised Nuclear Device (IND): A device incorporating radioactive materials designed to result in the formation of a nuclear-yield reaction. Such devices may be fabricated in a completely improvised manner or may be an improvised modification to a nuclear weapon. More.
Inner Area: An area with additional protection measures inside a protected area, where Category I nuclear material is used and/or stored. 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.
Intrusion Detection: Detection of an intruder by a guard or by a system that is in place. More.
Isolation zone: A restricted area around a facility that allows a vehicles or individuals to be seen due to an unobstructed view in the restricted area. More.
Local Communications: Communications that transfer details and tactical information among security personnel once they have arrived at the location of an emergency. More.
Material Access Area: A location that contains nuclear material. The physical barriers aka. walls/roof or vault are consider to be the area. More.
Nations that Are Parties to the Convention on the Physical Protection of Nuclear Material: Brazil, Bulgaria, Canada, Czechoslovakia, German Democratic Republic, Guatemala, Hungary, Indonesia, Republic of Korea, Liechtenstein, Mongolia, Norway, Paraguay, Philippines, Poland, Sweden, Switzerland, Turkey, Yugoslavia, Union of Soviet Socialists Republic, United States of America. More.
Nuclear Terrorism: An act of terrorism in which a person or persons belonging to a terrorist organization detonates a nuclear device. Some definitions of nuclear terrorism include the sabotage of a nuclear facility and/or the detonation of a radiological device, colloquially termed a dirty bomb, but consensus is lacking. More.
Nuisance Alarm: An alarm that is not caused by an unauthorized action. More.
Nuisance Alarm Rate (NAR): The expected rate of alarms from an intrusion detection sensor that can be attributed to known causes unrelated to intrusion attempts. More.
Outsider: An adversary other than an insider. More.
Path: A physical route taken by an adversary to achieve their goal. More.
Patrol: A group of guards that is intended to inspect the facility and check for potential intrusions. More.
Performance Criteria Approach: The specifications of the physical protection system on what is intended for the system to perform. More.
Physical Barrier: A fence or wall or a similar impediment which provides penetration delay and complements access control. More.
Physical Protection Systems: An integrated set of physical protection measures intended to prevent the completion of a malicious act. More.
Physical Security: Measures (including structural, technical and administrative protective measures) taken to prevent an adversary from achieving an undesirable consequence (such as radiological sabotage, or the unauthorized removal of nuclear or other radioactive material in use, storage or transport) and to mitigate or minimize the consequences if the adversary initiates such a malicious act. 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.
Probability of interruption: The mathematical likelihood that a protection or surveillance system in place successfully detects an adversary and then leads to the successful engagement and prevention of the adversary by response forces. More.
Probability of Neutralization: The mathematical likelihood that an adversary will be neutralized by the response forces. More.
Probability of sensing: The mathematical likelihood that a sensor in place will alarm for an intrusion given that certain conditions have been met. More.
Protected Area: Area inside a limited access area containing Category I or II nuclear material and/or sabotage targets surrounded by a physical barrier with additional physical protection measures. More.
Radiological Dispersion Device (RDD): A device to spread radioactive material using conventional explosives or other means. More.
Radiological Exposure Device (RED): A device with radioactive material designed to intentionally expose members of the public to radiation More.
Requirements for Physical Protection Against Unauthorized Removal of Nuclear Material in Use and Storage: A list of requirements needed by the IAEA to minimize the possibility of an adversary removing unauthorized nuclear materials. More.
Response force time: The period of time necessary for a component to achieve a specified output state from the time that it receives a signal requiring it to assume that output state. More.
Response Forces: 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.
Risk Assessment: Assessment of the radiological risks associated with normal operation and possible accidents involving a source or practice. More.
Sabotage: Any deliberate act directed against an associated facility or an associated activity that could directly or indirectly endanger the health and safety of personnel, the public, or the environment by exposure to radiation or release of radioactive substances. More.
Scenario: A path that an adversary derives in order to achieve their goal. More.
Security Survey: A detailed examination, made by the State’s competent authority, of proposed physical protection measures in order to evaluate them for approval. More.
Single path analysis: The mathematical estimate that looks at a given pathway and determines the risk that an adversary can attack from that pathway. More.
Stealth: The attempt to avoid being detected by the physical protection system by avoiding or disabling parts of the system. More.
Target: the objective of an attack. Also called an asset More.
Target Identification: The process of evaluating a facility to determine locations where an adversary might accomplish objectives. More.
Theft: The removal of nuclear material or information from a facility that was not authorized. 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.
Threat Assessment: An evaluation of the threats –based on available intelligence, law enforcement, and open source information- that describes the motivation, intentions, and capabilities of these threats. More.
Timely detection: The probability of detection of an adversary while there is still time for response forces to stop the adversary from accomplishing their intended goal. More.
Transport: International or domestic carriage of nuclear material by any means of transportation, beginning with the departure from a facility of the shipper and ending with the arrival at a facility of the receiver. More.
Transport Control Center: A facility which provides for the continuous monitoring of a transport conveyance location and security status and for communication with the transport conveyance, and the shipper/receiver, and when appropriate its guards, and the response forces. More.
Unauthorized Removal: The theft or other unlawful taking of nuclear material. More.
Upgrade: Improvements and modifications of existing systems to improve effectiveness. More.
Vehicle-born improvised explosive device: Devices that use a vehicle as the package or container of the device. More.
Vital Area: Area inside a protected area containing equipment, systems or devices, or nuclear material, the sabotage of which could directly or indirectly lead to high radiological consequences. More.
Vulnerability: An exploitable weakness of deficiency found at a facility usually of security interest. More.
Zone: A space that surrounds (but may not be occupied by) one or more targets and in which the functions of the physical protection system are to be accomplished. More.