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REGDOC-3.6, Glossary of CNSC Terminology- Glossary - F

facility (installation)

See nuclear facility.


With respect to safeguards, a nuclear reactor, critical facility, conversion plant, fabrication plant, reprocessing plant, isotope separation plant or a separate storage installation, or any location where nuclear material in amounts greater than 1 effective kilogram is customarily used.

facility and equipment (installation et équipement)

A functional area that groups 3 of the 14 safety and control areas (SCAs) within the CNSC SCA Framework: safety analysis, physical design, and fitness for service. Other functional areas are “core control processes” and “management”.

facility configuration information (renseignements sur la configuration de l’installation)

Recorded information that describes, specifies reports, certifies, or provides data or results regarding the design requirements or design basis, or that pertains to other information attributes associated with the facility and its structures, systems and components.


Fukushima action item

fail-safe (à sûreté intégrée)

The ability of a system or component to move to a predetermined safe state when a failure occurs.

fail-safe design (conception à sûreté intégrée)

A design whose most probable failure modes do not result in a reduction of safety.

failure (défaillance)

The inability or interruption of the ability of a structure, system or component to function within acceptance criteria. Also called fault.

failure criterion (critère de défaillance)

The measure point at which a structure, system or component is considered unable to meet its success criterion.

failure diagnosis (diagnostic de défaillance)

A structured process for determining the cause(s) of failure of a structure, system or component.

fast loss of reactivity control (FLORC) (perte rapide de contrôle de la réactivité [PRCR])

The loss of a nuclear reactor’s designed ability to measure, control and maintain reactivity by quickly inserting or removing reactivity devices. Only loss of reactivity control accidents that result in reactor power increase pose a safety concern.

fatality (décès)

Any death resulting from an injury or illness regardless of time intervening between the injury or illness and death. Note: With respect to reporting requirements, fatalities will be reported but no days will be charged to the event.

fatigue (fatigue)

A state of reduced mental or physical performance capability resulting from sleep loss, extended wakefulness, phase of the circadian rhythm or workload.

fault (défaut)

A rock fracture that has slipped, grinding or polishing the fractured surface. Faults are classified according to the direction of slippage.


With respect to nuclear facilities, a synonym for failure. See failure.

federal authority (autorité fédérale)
  1. a Minister of the Crown in right of Canada;
  2. an agency of the Government of Canada or a parent Crown corporation, as defined in subsection 83(1) of the Financial Administration Act, or any other body established under an Act of Parliament that is ultimately accountable through a Minister of the Crown in right of Canada to Parliament for the conduct of its affairs;
  3. any department or departmental corporation that is set out in Schedule I or II to the Financial Administration Act;
  4. any other body that is set out in Schedule 1 to the Canadian Environmental Assessment Act, 2012; and
  5. the Executive Council of – or a minister, department, agency or body of the government of – Yukon, the Northwest Territories or Nunavut.

It does not include a council of the band within the meaning of the Indian Act, Export Development Canada or the Canada Pension Plan Investment Board. It also does not include a Crown corporation that is a wholly-owned subsidiary, as defined in subsection 83(1) of the Financial Administration Act, a harbour commission established under the Harbour Commissions Act or a not-for-profit corporation that enters into an agreement under subsection 80(5) of the Canada Marine Act, that is not set out in Schedule 1 of the Canadian Environmental Assessment Act, 2012.

(Sources: Class I Nuclear Facilities Regulations; Uranium Mines and Mills Regulations)

feeder (tuyau d’alimentation)

In a CANDU reactor, one of a set of pipes attached to each end of the several hundred channels used to circulate heavy water coolant from fuel channels to steam generators.

fee period (période d’application des droits)

The 12-month period beginning on the date of issuance of a licence and, after that date, beginning on each anniversary date of the licence. (Source: Canadian Nuclear Safety Commission Cost Recovery Fees Regulations)


Federal Emergency Response Plan

fertile material (matière fertile)

Nuclear material that can be converted into a special fissionable material through the capture of one neutron per nucleus. There are two naturally occurring fertile materials: uranium-238 and thorium-232. Through the capture of neutrons followed by two beta decays, these fertile materials are converted to fissionable plutonium-239 and uranium-233, respectively.

FFD (aptitude au travail)

See fitness for duty.

financial guarantee (garantie financière)

The establishment and maintenance of a financial arrangement that will assure adequate funding of a decommissioning program.


fuel incident notification and analysis system

finding (constatation)

A conclusion that results from the evaluation of facts collected during an inspection against inspection criteria. A finding can indicate either compliance or non-compliance with inspection criteria.

fire (incendie)

A process of combustion characterized by heat emission and accompanied by smoke or flame, or both.

First Nations (Autochtones)

SeeAboriginal peoples of Canada or Indigenous peoples.

fiscal year (FY) (exercice)

The period beginning on April 1 in one calendar year and ending on March 31 in the next calendar year. (Source: Canadian Nuclear Safety Commission Cost Recovery Fees Regulations)

fissile assembly (assemblage fissile)

A system consisting of fissile material and other components that significantly influence reactivity. Also called assembly.

fissile-excepted radioactive material (matière radioactive fissile exceptée)

Fissile radioactive material that is

  1. excepted from being classified as fissile in accordance with the IAEA Regulations; or
  2. contained in a package that is excepted from being classified as fissile in accordance with those Regulations.

(Source: Packaging and Transport of Nuclear Substances Regulations, 2015)

fissile isotope (isotope fissile)

Plutonium, uranium-235 or uranium-233.

fissile material (matière fissile)

Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)

Note: This definition is restricted to packaging and transport of nuclear substances.


A material that is capable of sustaining a thermal neutron chain reaction. Note: This definition does not apply to packaging and transport of nuclear substances.


With respect to nuclear criticality safety, a material, other than natural uranium, that is capable of sustaining a thermal neutron chain reaction.

fissile nuclide (nucléide fissile)

A nuclide capable of undergoing fission by interaction with slow neutrons provided the effective thermal neutron production cross-section, υσf, exceeds the effective thermal neutron absorption cross-section σa.

fissionable (fissionnable)

Capable of undergoing fission.

fissionable material (matière fissionnable)

Any material that can undergo nuclear fission.

fitness for duty (FFD) (aptitude au travail)

A condition in which workers are physically, physiologically and psychologically capable of competently and safely performing their tasks. See also for-cause testing; post-incident testing; pre-placement testing; reasonable grounds testing.

fitness for service SCA (DSR Aptitude fonctionnelle)

A safety and control area (SCA) that covers activities that impact the physical condition of structures, systems and components to ensure that they remain effective over time. This includes programs that ensure all equipment is available to perform its intended design function when called upon to do so. This SCA is one of the 14 within the CNSC SCA Framework.

five-year dosimetry period (période de dosimétrie de cinq ans)

The period of five calendar years beginning on January 1 of the year following the year in which these Regulations come into force, and every period of five calendar years after that period. (Source: Radiation Protection Regulations)

Note: These periods cover 2001–05, 2006–10, 2011–15, 2016–20 and 2021–25.

fixed gauge (jauge fixe)

See fixed nuclear gauge.

fixed moderator (modérateur fixe)

A moderator with an established geometric relationship to the locations occupied by the fixed neutron absorber and fissionable material.

fixed neutron absorbers (absorbeurs de neutrons fixe)

Neutron absorbers in solids with an established geometric relationship to the locations occupied by fissionable material.

fixed nuclear gauge (jauge nucléaire fixe)

A radiation device that is attached to a structure and enables the nuclear substance contained in it to be used for its radiation properties to measure process-related parameters (such as liquid flow or liquid level).


See fast loss of reactivity control.


Federal Nuclear Emergency Plan

follow-up testing (test de dépistage de suivi)

Testing that is part of a follow-up plan to verify an individual’s continued abstinence from substance abuse.

for cause (pour un motif valable)

A threshold for action (interview, further checks, denial, revocation, suspension).


In the context of a security assessment, a determination that more in-depth verifications are required due to gaps in information or information that could not be verified.


A determination by the licensee that sufficient evidence exists regarding an unreasonable security risk to the licensed site, including its operation and personnel, or a threat with national security implications.

for-cause testing (test de dépistage pour raison valable)

With respect to fitness for duty, methods to determine workers’ fitness for duty. For-cause testing includes post-incident testing and reasonable grounds testing. See also fitness for duty; post-incident testing; reasonable grounds testing.

forced outage (arrêt imprévu)

A reactor shutdown resulting in an outage that had not been identified in the licensee’s long-term plan or that is not due to a surplus baseload generation request.

foreign national (ressortissant étranger)

A person who is not a Canadian citizen or a permanent resident of Canada.

foreign obligations (obligations à l’étranger)

See obligations.

fraudulent item (article frauduleux)

An item whose material, performance or characteristics are knowingly misrepresented with intent to deceive.
Note: Some examples are items provided with incorrect identification, or falsified or inaccurate certification. Other examples include manufacturing overages sold by entities with the legal right to manufacture a specified quantity of an item but that produce a larger quantity than authorized, which is then sold as legitimate inventory.

free neutron (neutron libre)

See neutron radiation.

freight container (conteneur)

Has the same meaning as in the International Maritime Dangerous Goods Code. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)

frequented by fish (eaux où vivent des poissons)

See water frequented by fish.


fully satisfactory; see safety performance rating methodology

fuel bay (piscine de combustible)

See wet storage bay.

fuel burnup (combustion nucléaire)

The induced nuclear transformation of atoms during reactor operation, usually measured as energy generated in the fuel during its residence in the reactor core per unit mass of fuel (such as gigawatt-days per tonne of uranium). Also called burnup.

fuel cooling system (système de refroidissement du combustible)

With respect to reactor buildings, any cooling system whose failure has the potential to release radioactive material in excess of established limits.

fuel deformation (déformation du combustible)

A change in the geometry of a fuel bundle caused by deformation of one or more elements in the bundle or of the whole bundle.

fuel failure (défaillance du combustible)

Any rupture of a fuel sheath such that fission products may be released.

fuel rod (barre de combustible)

A long slender column of material containing fissile nuclides. The rod is normally encapsulated by metallic tubing.

fuel sheath dryout (assèchement de la gaine de combustible)

With respect to heat transfer in a reactor core, the formation of a vapour blanket over the fuel sheath during some accident conditions when the liquid coolant, which flows over the fuel during normal operation to cool the fuel, boils off.

fuel unit (unité de combustible)

The fundamental item for handling, storing or transporting fuel. The fuel unit may be an assembly of fuel rods, canned spent fuel, or consolidated fuel rods.

full cost (coût entier)

The sum of the costs of the Commission’s direct regulatory activities and indirect regulatory activities, including salaries and benefits, rental of office accommodation, supplies and equipment, professional services, communications, travel and training. (Source: Canadian Nuclear Safety Commission Cost Recovery Fees Regulations)

full scope simulator (simulateur pleine échelle)

A simulator that can perform detailed modelling of the response of the systems of a given nuclear power plant (NPP) under normal, abnormal and accident conditions. The simulator is equipped with a replica of the NPP main control room panels where operators can interface with the simulated plant systems in the control room environment.

fully satisfactory (FS) (entièrement satisfaisant [ES])

See safety performance rating methodology.

function testing (essai de fonctionnement)

Testing done to verify that a structure, system or component is capable of performing its design function.

functional indicator (indicateur du fonctionnement)

A condition indicator that directly shows the current ability of a structure, system or component to function within acceptance criteria.

Fussell-Vesely (FV) importance (mesure d’importance de Fussell-Vesely [FV])

See importance measures.


Fussell-Vesely. See importance measures.

FY (exerice)

See fiscal year.

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