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

package (colis)

Packaging with its radioactive contents, as presented for transport. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)

packaging (emballage)

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

packaging and transport SCA (DSR Emballage et transport)

A safety and control area (SCA) that covers programs for the safe packaging and transport of nuclear substances to and from the licensed facility. This SCA is one of the 14 within the CNSC SCA Framework.

panel (formation)

A panel of the Commission consisting of one or more members established by the President under section 22 of the Act. (Source: Canadian Nuclear Safety Commission By‑laws)

PAR (recombineur autocatalytique passif)

passive autocatalytic recombiner; also called passive autocatalytic hydrogen recombiner

parameter expectations (valeurs prévues des paramètres)

Measures or criteria against which the performance of a structure, system or component can be judged.

participant (participant)

A party or intervenor. (Source: Canadian Nuclear Safety Commission Rules of Procedure)


An individual who is taking part in an emergency drill or exercise and responding to the simulated events.

particle accelerator (accélérateur de particules)

A device that accelerates particles to extremely high speeds, for the purpose of inducing high energy reactions or producing radiation.

party (partie)


  1. in relation to a licence application, the applicant;
  2. in relation to a licence renewal, suspension, amendment, revocation or replacement, the licensee;
  3. in relation to a matter being heard by the Commission in the public interest under the Act, and if these Rules do not otherwise set out who the parties are, any person whom the Commission names as party in the proceeding;
  4. in relation to the review by the Commission of an order of an inspector or a designated officer, a person who is named in or subject to the order;
  5. in relation to an appeal made to the Commission under subsection 43(1) of the Act, the appellant;
  6. in relation to a rehearing and redetermination under subsection 43(2) of the Act, any of the persons referred to in that subsection; and
  7. in relation to a redetermination on the Commission’s own initiative under subsection 43(3) of the Act, any of the persons referred to in subsection 43(2) of the Act.

(Source: Canadian Nuclear Safety Commission Rules of Procedure)


See personal air sampler.

passenger (passager)

Has the same meaning as in section 1.4 of the Transportation of Dangerous Goods Regulations.

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

passive component (composant passif)

A component that functions without depending on an external input such as actuation, mechanical movement or supply of power.

passive engineered (nuclear) criticality safety control (contrôle technique passif de sûreté‑criticité [nucléaire])

See engineered (nuclear) criticality safety control.


See pressure boundary degradation.


pulsed dose rate

penalty (pénalité)

An administrative monetary penalty imposed under this Act for a violation. (Source: Nuclear Safety and Control Act)


Provincial Emergency Operations Centre

performance evaluation (évaluation de la performance)

With respect to reliability programs, analysis based on initial objectives and estimates and usually made onsite, in order to provide information on operating experience and identify required corrective actions.

performance indicator (PI) (indicateur de rendement)

A quantifiable variable related to the actions of a proposed or licensed activity that may cause or indicate an adverse environmental effect if a certain threshold value is reached. Note: For reporting requirements for nuclear power plants, see safety performance indicator.

performance monitoring (surveillance de la performance)

With respect to reliability programs, the determination of whether equipment is operating or is capable of operating within specific limits.

performance target (objectif de rendement)

With respect to environmental protection, a limit on a performance indicator designed to prevent unreasonable risks to the environment. Note: More than one limit may be set or considered for a performance indicator.

performance testing (essai de performance)

Testing done to determine whether a system meets specified acceptance criteria.

periodic inspection (inspection périodique)

Examination of safety-significant pressure/fluid boundary components or containment components carried out in accordance with program requirements specified in the licence conditions handbook for a reactor facility. See also in-service inspection.

periodic maintenance (entretien périodique)

A form of preventive maintenance for structures, systems and components, which consists of servicing, parts replacement, surveillance, or testing at predetermined intervals of calendar time, operating time or number of cycles. Also called time-based maintenance.

periodic safety review (PSR) (bilan périodique de la sûreté [BPS])

A comprehensive assessment of nuclear power plant design and operation that deals with the cumulative effects of aging, modifications, operating experience, technical developments and siting factors, and aims at ensuring a high level of safety throughout the operating life of the plant.

periodic safety review (PSR) basis document (document de fondement du bilan périodique de la sûreté (BPS))

The information that sets out the scope and methodology for the conduct of a periodic safety review.

permanent repair (réparation permanente)

Any activity that restores a failed or degraded structure, system or component to function within its original design.

personal air sampler (PAS) (échantillonneur d’air personnel [EAP])

An air sampler, consisting of a filter holder and battery-powered vacuum pump, which is worn by a worker to estimate breathing zone concentrations of radionuclides. Also called lapel sampler.

personnel qualification (qualifications du personnel)

A formal statement that an individual or team possesses the education, training and experience required to meet specified job performance requirements. The personnel qualification is a formal statement of competence.

Personnel Security Standard (Norme sur la sécurité du personnel)

The document entitled Chapter 2 – 4 – Personnel Security Standard, published by the Treasury Board Secretariat and dated June 9, 1994, as amended from time to time. (Source: Nuclear Security Regulations)


See positron emission tomography.


See primary heat transport system.

physical design SCA (DSR Conception matérielle)

A safety and control area (SCA) that relates to activities that impact the ability of structures, systems and components to meet and maintain their design basis given new information arising over time and taking changes in the external environment into account. This SCA is one of the 14 within the CNSC SCA Framework.

physical inventory (stock physique)

With respect to nuclear material accounting, the sum of all the measured or derived estimates of batch quantities of nuclear material at a given time within a material balance area obtained in accordance with the licensees’ (CNSC-approved) program and procedures.

physical inventory verification (PIV) (vérification des stocks physiques [VSP])

With respect to safeguards, an inspection activity carried out by the International Atomic Energy Agency to confirm that the amount of nuclear material actually present at a given time within a material balance area is in agreement with the operator’s recorded book inventory of nuclear material.

physical protection measure (mesure de protection physique)

An element or a combination of elements in place at a nuclear facility for its protection – or for the protection of nuclear substances at the facility – against potential adversaries. (Source: Nuclear Security Regulations)

Note: Physical protection measures also apply during transport of nuclear substances.

physical protection system (PPS) (système de protection physique [SPP])

All of the physical protection measures in place at a nuclear facility. (Source: Nuclear Security Regulations)

Note: The physical protection measures include multiple obstacles or barriers, either similar or diverse, to prevent adversaries from achieving their goal. The physical protection system also applies during transport of nuclear substances.

physical protection system support person (préposé au soutien du système de protection physique)

A person who:

  1. carries out the design, implementation, maintenance or repair of a physical protection system at a high-security site or conducts training related to one or more of those activities; and
  2. is likely to be exposed to, or gain knowledge of, prescribed information in carrying out the activities referred to in paragraph (a).

(Source: Nuclear Security Regulations)

PI (indicateur de rendement)

See performance indicator.


See postulated initiating event.


See potential intake fraction.

pilot course (cours pilote)

A trial of a training program before it is implemented as regular training.


See physical inventory verification.

planned maintenance (entretien planifié)

A form of preventive maintenance consisting of refurbishment or replacement that is scheduled and performed prior to an unacceptable degradation of a structure, system or component.

planned work (travail planifié)

Major safety-significant work scheduled in a nuclear reactor outage, which, in the licensee’s judgment, is of regulatory interest but is not mandatory or committed, including:

  • repair or maintenance tasks to correct known problems (such as level 3 impairments)
  • inspection tasks (such as periodic inspection program (PIP) work) that must be completed over a multi-year cycle and for which there is another planned maintenance outage before the end of the current cycle
  • requests from CNSC staff to do additional inspections beyond the PIP requirements
  • additions to outage scope, such as component repairs or replacement, resulting from conducting a planned inspection during the outage
planning envelope (enveloppe de planification)

With respect to decommissioning planning, a definable part or area of a facility that is sufficiently removed from, or otherwise independent of, other parts or areas so that the strategic approach to decommissioning that part or area may be planned in a relatively independent manner. For example, processing, administration and waste management areas may all fall within relatively independent decommissioning planning envelopes.

plant configuration (configuration de la centrale)

The physical, functional and operational characteristics of the structures, systems and/or components and parts of a facility, including the organizational structure.

plant design envelope (enveloppe de conception de la centrale)

See design envelope.

plant experience (expérience en centrale)

With respect to certification of a person, the experience gained at a nuclear facility during commissioning, start‑up testing or operation that is relevant to the position for which a person seeks certification.

plant parameters (paramètres de la centrale)

Parameters that characterize the state of the plant’s structures, systems and components, or that are used to actuate a mitigating system. Also called operational parameters.

plant shift supervisor (chef de quart de centrale)

The person in a nuclear power plant (NPP) who is responsible for directly supervising its operation. The plant shift supervisor also ensures that operations and maintenance are conducted in accordance with the NPP licence, policies and procedures, and with the applicable requirements specified in federal and provincial acts and regulations, and in other relevant standards and codes. The plant shift supervisor is the NPP management’s representative on shift.

plant state (état de la centrale)

A configuration of reactor facility components, including the physical and thermodynamic states of the materials and the process fluids in them. Note: With respect to reactor facility design, a plant is said to be in one of the following states: normal operation, anticipated operational occurrence, design-basis accident, or beyond-design-basis accident (severe accidents and design extension conditions are a subset of the beyond-design-basis state), as shown in figure 1. Note also that operators of non-power reactors commonly use the term reactor state.

Figure 1: Plant states

Operational states

Accident conditions

Normal operation

Anticipated operational occurrence

Design-basis accident

Beyond-design-basis accident

Design extension conditions

Practically eliminated conditions

No severe fuel degradation

Severe accidents

Design basis

Design extension

Not considered as design extension

Reducing frequency of occurrence

point-kernel technique (technique des noyaux ponctuels)

A technique based on an analysis point source solution where the unattenuated flux at any distance r from the source point is proportional to the source rate divided by 4πr2. Attenuations are treated in an approximate manner through the use of built‑in attenuation.

poison (poison)

See neutron absorber.

polluter pays (pollueur-payeur)

A principle that is based on the concept that users and producers of pollutants and wastes should bear the responsibility for their actions. Note: This concept – that companies or people that pollute should pay the costs they impose on society – is one of the guiding principles of the Canadian Environmental Protection Act, 1999.

pollution prevention (prévention de la pollution)

The use of processes, practices, materials, products, energy or substances that avoid or minimize the creation of pollutants and waste and reduce the overall risk to the environment or to human health. (Source: Canadian Environmental Protection Act, 1999)

Note: Within pollution prevention, the CNSC also includes, where necessary, the use of environmental controls to prevent or minimize releases to the environment.

poly‑energetic source (source polyénergétique)

A source that has multiple radiation emissions of unique energies.

portable gauge (jauge portative)

See portable nuclear gauge.

portable nuclear gauge (jauge nucléaire portative)

A portable radiation device used to measure density, level, thickness or moisture content.

positron emission tomography (PET) (tomographie par émission de positrons [TEP])

An imaging procedure that detects gamma rays that are emitted when positrons from a positron-emitting source (such as fluorine‑18) collide with electrons in tissue.

possess (avoir en sa possession)

For licensing purposes, have the care and control of a nuclear substance(s) or radiation device(s). Note that having possession is distinct from ownership.

possession limit (limite de possession)

The total quantity for each unsealed source (nuclear substance) in storage, in use and being held before disposal. Note: The maximum quantity in possession, which is specified in the licence for each unsealed source (nuclear substance), may not be exceeded at any time.

post-dryout operation (fonctionnement après assèchement)

The high-power operation that continues between the start of fuel sheath dryout until reactor shutdown, under anticipated operational occurrences or accident conditions. Note: The automatic shutdown system may shut the reactor down if operator action and/or the reactor regulating system are ineffective.

post-incident testing (test de dépistage à la suite d’un incident)

An element of for-cause testing, whereby an alcohol or drug test is administered to a worker designated in a safety-critical or safety-sensitive position as soon as practical after a significant incident, where an act or omission by the worker may have caused or contributed to the event. See also fitness for duty; for-cause testing; pre-placement testing; reasonable grounds testing; safety significance.

postulated initiating event (PIE) (événement initiateur hypothétique [EIH])

An event identified in a design as leading to either an anticipated operational occurrence or accident conditions. Note: Not necessarily an accident itself, a PIE is the event that initiates a sequence that may lead to an operational occurrence, a design-basis accident, or a beyond-design-basis accident, depending on the additional failures that occur. See also initiating event.

potential adversary (agresseur potentiel)

Any person – whether or not they have authorized access to a nuclear facility – who might attempt:

  1. the unauthorized removal of Category I, II or III nuclear material; or
  2. sabotage.

(Source: Nuclear Security Regulations)

potential intake fraction (PIF) (fraction d’incorporation potentielle [FIP])

A dimensionless quantity that defines intake as a fraction of exposure to contamination. A PIF is a function of several factors: release, confinement, dispersability, occupancy. For example, PIF=0 for encapsulated material, as no intake of radioactive nuclear substances into a worker’s body can occur.


personal protective equipment


See physical protection system or preferred power supply.


probabilistic risk analysis or probability risk assessment; see probabilistic safety assessment

practicable (réalisable)

Technically feasible and justifiable while taking cost-benefit considerations into account.

practically eliminated (pratiquement éliminée)

A way of describing that, for all practical purposes, specified accident conditions are physically impossible or extremely unlikely to occur.

precautionary principle (principe de la prudence)

The principle that where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation. (Sources: Canadian Environmental Protection Act, 1999 (preamble); Federal Sustainable Development Act)

Note 1: In other words, precautions should always be taken to prevent environmental degradation, even in the absence of full scientific certainty – especially when there is a possibility of serious or irreversible damage.

Note 2: The “precautionary principle” is discussed in additional detail in A Framework for the Application of Precaution in Science-based Decision Making about Risk [7].

predicted reliability (fiabilité prévue)

The predicted probability that a system will meet its success criterion when required to do so. This is calculated using current reliability data.

predictive maintenance (entretien prédictif)

A form of preventive maintenance performed continuously or at intervals governed by observed condition to monitor, diagnose or trend the condition indicators of a structure, system or component. Results indicate current and future functional ability or the nature of and schedule for planned maintenance. See also condition-based maintenance.

preferred power supply (PPS) (alimentation électrique préférée [AEP])

The power supply from the transmission system or the plant generator to the electrical distribution systems classified as important to safety. This power supply is preferred for safety support functions for normal operations, anticipated operational occurrences, design-basis accidents and design extension conditions.

preliminary decommissioning plan (plan préliminaire de déclassement)

An overview of a proposed decommissioning approach that is sufficiently detailed to assure that the proposed approach is, in the light of existing knowledge, technically and financially feasible and appropriate in the interests of health, safety, security and protection of the environment. Note: The decommissioning plan defines areas to be decommissioned and the general structure and sequence of the principal decommissioning work packages envisioned. As such, the plan forms the strategic basis for establishing financial guarantees and provides the structural outline of the subsequent detailed decommissioning plan(s).

pre-placement testing (test préalable à l’affectation)

An assessment of fitness for duty of an applicant to a safety-critical position before employment begins or a fitness-for-duty assessment conducted before the transfer of an incumbent worker into a safety-critical position. See also fitness for duty; for-cause testing; post-incident testing; reasonable grounds testing.

prescribed (réglementaire ou réglementé)

Prescribed by regulation of the Commission. (Source: Nuclear Safety and Control Act)

Note: Within the CNSC’s mandate, prescribe means to impose authoritatively.

prescribed equipment (équipement réglementé)

The equipment prescribed by section 20. (Source: General Nuclear Safety and Control Regulations)

Note 1: Section 20 states that each of the following items is prescribed equipment for the purposes of the NSCA:

  1. a package, special form radioactive material, low dispersible radioactive material, fissile-excepted radioactive material, radioactive material that has a basic radionuclide value that is not listed in the IAEA Regulations and an instrument or article that has an alternative activity limit for an exempt consignment, as those terms are defined in subsection 1(1) of the Packaging and Transport of Nuclear Substances Regulations, 2015;
  2. a radiation device and a sealed source, as defined in section 1 of the Nuclear Substances and Radiation Devices Regulations;
  3. Class II prescribed equipment, as defined in section 1 of the Class II Nuclear Facilities and Prescribed Equipment Regulations; and
  4. equipment that is capable of being used in the design, production, operation or maintenance of a nuclear weapon or nuclear explosive device.

Note 2: All controlled nuclear equipment is prescribed equipment for the purposes of the NSCA, with respect to the import and export of that equipment. See also controlled nuclear equipment.

prescribed information (renseignements réglementés)

The information prescribed by section 21. (Source: General Nuclear Safety and Control Regulations)

Note 1: Section 21 states that information that concerns any of the following, including a record of that information, is prescribed information for the purposes of the Nuclear Safety and Control Act (NSCA):

  1. a nuclear substance that is required for the design, production, use, operation or maintenance of a nuclear weapon or nuclear explosive device, including the properties of the nuclear substance;
  2. the design, production, use, operation or maintenance of a nuclear weapon or nuclear explosive device;
  3. the security arrangements, security equipment, security systems and security procedures established by a licensee in accordance with the Act, the regulations made under the Act or the licence, and any incident relating to security; and
  4. the route or schedule for the transport of Category I, II or III nuclear material, as defined in section 1 of the Nuclear Security Regulations.

Note 2: All controlled nuclear information is prescribed information for the purposes of the NSCA, with respect to the import and export of that information, unless it is made public in accordance with the NSCA, the regulations made under the NSCA or a licence. See also controlled nuclear information.

prescribed nuclear facilities (installations nucléaires réglementées)

The facilities prescribed by section 19 of the General Nuclear Safety and Control Regulations.

Note 1: Section 19 states that the following facilities are prescribed as nuclear facilities for the purpose of paragraph (i) of the definition “nuclear facility” in section 2 of the Nuclear Safety and Control Act (NSCA):

  1. a facility for the management, storage or disposal of waste containing radioactive nuclear substances at which the resident inventory of radioactive nuclear substances contained in the waste is 1015 Bq or more;
  2. a plant for the production of deuterium or deuterium compounds using hydrogen sulphide; and
  3. a Class II nuclear facility, as defined in section 1 of the Class II Nuclear Facilities and Prescribed Equipment Regulations.

Note 2: Bq means becquerels.

pressure boundary (enveloppe sous pression)

A boundary of a pressure-retaining structure, system or component of a nuclear or non‑nuclear system. Note: This definition applies to components subject to registration under applicable boiler and pressure vessel legislation.

pressure boundary degradation (PBD) (dégradation d’une enveloppe de pression [DEP])

A change in a pressure boundary’s condition that exceeds any relevant limit specified in the applicable design analysis, design codes or standards, or inspection codes or standards.

President (président)

The President of the Commission designated under subsection 10(3) of the Act. (Source: Canadian Nuclear Safety Commission By-laws)

preventative maintenance (entretien préventif)

See preventive maintenance.

prevention (prévention)

In the context of severe accident management, measures aimed at averting or delaying the onset of a severe accident.

preventive maintenance (entretien préventif)

Actions that detect, preclude or mitigate degradation of a functional structure, system or component to sustain or extend its useful life by controlling degradation and failures to an acceptable level. Preventive maintenance may be periodic, planned or predictive. Also called preventative maintenance.

primary and backup (secondary) trip parameter (paramètre de déclenchement primaire ou secondaire)

For CANDU nuclear power plants, the designations for trip parameters, as established through safety analyses. On each shutdown system, the trip parameter predicted to come earliest is the primary trip parameter; the one predicted to come after it is the backup trip parameter.

primary coolant system (circuit primaire de refroidissement)

See primary heat transport system.

primary heat transport system (PHTS) (circuit caloporteur primaire [CCP])

The system of components in certain nuclear reactors that permit the transfer of heat from the fuel in the reactor to the steam generators or other heat exchangers employing secondary cooling. The PHTS does not necessarily include auxiliary purification and pressure control subsystems. Also called primary coolant system; reactor coolant system.

primary method of criticality control (méthode principale de contrôle de la criticité)

A control parameter on which principal reliance is placed in assuring that subcritical conditions are maintained.

primary side (côté primaire)

The primary heat transport system. See also secondary side.

primary trip parameter (paramètre de déclenchement primaire)

See primary and backup (secondary) trip parameter.

probabilistic risk analysis (analyse probabiliste de la sûreté)

See probabilistic safety assessment.

probabilistic risk assessment (PRA) (étude probabiliste de sûreté [EPS])

See probabilistic safety assessment.

probabilistic safety analysis (analyse probabiliste de la sûreté)

See probabilistic safety assessment.

probabilistic safety assessment (PSA) (étude probabiliste de sûreté [EPS])

A comprehensive and integrated assessment of the safety of a facility. The safety assessment considers the probability, progression and consequences of equipment failures or transient conditions to derive numerical estimates that provide a consistent measure of the safety of the facility, as follows:

  • a Level 1 PSA identifies and quantifies the sequences of events that may lead to the loss of core structural integrity and massive fuel failures
  • a Level 2 PSA starts from the Level 1 results, analyzes the containment behaviour, evaluates the radionuclides released from the failed fuel and quantifies the releases to the environment
  • a Level 3 PSA starts from the Level 2 results, analyzes the distribution of radionuclides in the environment and evaluates the resulting effect on public health

This term is the one commonly used in Canada; however, the terms probabilistic risk assessment and probabilistic risk analysis are also used sometimes.

process evaluation (évaluation de procédé)

See nuclear criticality process evaluation.

process system (système fonctionnel)

A system whose primary function is to support (or contribute to) the production of steam or electricity.

program evaluation (évaluation du programme)

An assessment of a program’s merit or value. A program evaluation is a systematic process designed to collect data to assess if the program has satisfied its objectives in the most effective and efficient manner.

programmatic failure (défaillance en matière de programme)

The occurrence of one or both of the following circumstances:

  • failure to establish or comply with a required program or program element as credited in the licensing basis
  • aggravated or systemic failure(s) to adhere to applicable procedures

Also called programmatic non‑compliance. Note: Individual acts of non‑compliance with licensee-produced documents that have no immediate or short-term regulatory or safety consequences and that are not indicative of programmatic failures are not considered safety-significant situations or events.

programmatic non‑compliance (non‑conformité en matière de programme)

See programmatic failure.

projection sheath (tube de guidage)

For exposure devices, a tube for guiding the sealed source assembly from an exposure container to the working position and having the necessary connections for attachment to the exposure container and to the exposure head, or including the exposure head itself. Also called guide tube.

projection sheath connector (raccord de la gaine d’injection)

A component used to attach the source projection sheath to an exposure device. Also called guide tube connector.


power reactor operating licence

proponent (promoteur)

The person, body, federal authority or government that proposes the carrying out of a designated project.

protected area (zone protégée)

An area that is surrounded by a barrier that meets the requirements of section 9. (Source: Nuclear Security Regulations)

protective zone (zone de protection)

The area beyond an exclusion zone that needs to be considered with respect to implementing emergency measures. Some considerations are population distribution and density, land and water usage, roadways, and consequence and evacuation planning.

proton (proton)

A stable subatomic particle that is found in the nucleus of an atom and has a positive electric charge.

proven design (conception éprouvée)

A design that shows compliance with accepted engineering standards through a history of experience, testing or some combination of these methods.


primary relief valve


See probabilistic safety assessment.


See periodic safety review.

public disclosure (divulgation publique)

The act of making information available to the public.


pressurized water reactor

pyrophoricity (pyrophoricité)

The property of a material or substance that ignites spontaneously when exposed to air or when rubbed or struck.

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