Glossary of CNSC Terminology
REGDOC-3.6

February 2023

Glossary of CNSC Terminology
Regulatory document REGDOC-3.6© Canadian Nuclear Safety Commission (CNSC) 2023

Extracts from this document may be reproduced for individual use without permission provided thesource is fully acknowledged. However, reproduction in whole or in part for purposes of resale orredistribution requires prior written permission from the CNSC.
Également publié en français sous le titre : Glossaire de la CCSN
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French, please contact:
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Last updated: February 2023

February 2023

REGDOC-3.6, Glossary of CNSC Terminology

PrefaceThis regulatory document is part of the CNSC’s series of regulatory documents. The full list of regulatory
document series is included at the end of this document and can also be found on the CNSC’s website.
Regulatory document REGDOC-3.6, Glossary of CNSC Terminology, provides a list of terms anddefinitions used in the Nuclear Safety and Control Act (NSCA), the regulations made under the NSCA,
and CNSC regulatory documents and other publications, such as annual reports and guidance documents.
This document is provided for reference and information and serves as the standard for future CNSC
regulatory documents and other publications.
REGDOC-3.6 is an evergreen document, first posted in December 2016. This update (February 2023)
replaces the version posted in May 2022.
All terms and definitions from the NSCA (also called the Act) and regulations made under it are
identified by source. Certain frequently used terms and definitions defined by other acts of Parliament arealso included and their sources are also identified. References to sections, subsections, paragraphs,
schedules or columns mean those belonging to the source (NSCA, regulation or other act) unlessotherwise specified.
Some terms are also used in CNSC licences and licence conditions handbooks. This glossary may include
minor edits of those terms and definitions; however, the definitions in this glossary do not supersede
licence conditions or other legally binding documents.
In most cases, the definitions have been previously published in CNSC documents. Where necessary, they
have been edited for grammar, consistency and accuracy. Where published sources provided multiple
definitions for a term, similar definitions were combined and edited for the same reason, or context wasadded where the meaning applies to a specific safety area or facility type.
This document is intended to be updated regularly. New terms and definitions will be added as new orrevised regulatory documents or other publications are published. Comments on terms and definitions arealways welcome; please contact the CNSC if you have any suggestions to improve this document’s
completeness, cohesiveness or clarity.

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REGDOC-3.6, Glossary of CNSC Terminology

Table of Contents
1.

2.

Introduction..........................................................................................................................1
1.1

Purpose................................................................................................................................ 1

1.2

Scope................................................................................................................................... 1

1.3

Relevant legislation............................................................................................................. 2

1.4

Additions and revisions ...................................................................................................... 2

Terms and Definitions ..........................................................................................................3A..............................................3M............................................80

B............................................11N............................................85C............................................16

O............................................92

D............................................32

P............................................96E............................................40

Q..........................................108

F............................................52

R..........................................109

G............................................58

S..........................................117

H............................................60

T..........................................136

I............................................63U..........................................143

J............................................73

V..........................................146

K............................................74

W..........................................148

L............................................74

X-Y-Z ..........................................151

Appendix A: Acronyms and Abbreviations ..................................................................................152
References ....................................................................................................................................159
Additional Information .................................................................................................................160

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REGDOC-3.6, Glossary of CNSC Terminology

Glossary of CNSC terminology
1.

Introduction
1.1

PurposeThis glossary is provided for reference and information and serves as the standard for future
CNSC regulatory documents and other publications.
The definitions in this glossary do not supersede licence conditions or other legally binding
documents.
1.2

Scope

The glossary provides a list of terms and definitions used in the Nuclear Safety and Control Act(NSCA; also called the Act), the regulations made under the NSCA, and CNSC regulatory
documents and other publications, such as annual reports and guidance documents. Acronyms
and abbreviations are also included.
Minor edits have been made to some terms and definitions from published CNSC regulatory
documents and other CNSC publications. Notes have been added to certain definitions to further
clarify them.
French terms
For each term, the French term is provided immediately following the English term.
Glossary structure
Most glossary entries consist of a term plus a definition, but may also have other information.
A term may have one or more definitions; for example:
safety analysis (analyse de la sûreté)
A systematic evaluation of the potential hazards that is associated with the conduct of a
proposed activity or facility and that considers the effectiveness of preventive measures andstrategies in reducing the effects of such hazards.
OR
With respect to deterministic safety analysis, analysis by means of appropriate analytical
tools that confirms the design basis for the items important to safety and ensures that theoverall nuclear facility design is capable of meeting specified acceptance criteria.
Cross-references are provided to the main or preferred term; for example:
poison (poison)
See neutron absorber.

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REGDOC-3.6, Glossary of CNSC Terminology

Acronyms are included – either with the defined term, or as a cross-reference or a standalone
entry where applicable; for example:
annual limit on intake (ALI) (limite annuelle d’incorporation [LAI])
The activity, in becquerel, of a radionuclide that will deliver an effective dose of 20 mSv
during the 50-year period after the radionuclide is taken into the body of a person 18 years
old or older or during the period beginning at intake and ending at age 70 after it is taken into
the body of a person less than 18 years old. (Source: Radiation Protection Regulations)
ALI (LAI)
See annual limit on intake.
RCS (SRR)
reactor coolant system
The glossary also lists alternate, but less frequently used terms, as well as a small number ofterms (not necessarily synonyms) that are more suitably defined under other ones. These alternate
terms are also cross-referenced to the appropriate terms, for example:
collimator (collimateur)
See beam limiter.
1.3

Relevant legislation

Sources
Terms and definitions from the NSCA, regulations made under the NSCA and other relevant
legislation are identified by the source; for example:
Class I nuclear facility (installation nucléaire de catégorie I)
A Class IA nuclear facility and a Class IB nuclear facility. (Source: Class I Nuclear Facilities
Regulations)
Each term is generally from the Interpretations section, but may appear in another section orsubsection of the legislation. Within any definition, references to sections, subsections,paragraphs, schedules or columns mean those belonging to the source unless otherwise specified.
IAEA Regulations
Throughout this document, the term “IAEA Regulations” refers to the most up-to-date
Regulations for the Safe Transport of Radioactive Material, published by the International
Atomic Energy Agency (IAEA).
1.4

Additions and revisions

This update (February 2023) replaces the version posted in May 2022.
Future updates to this document will incorporate new terms and definitions in newly publishedregulatory documents, capture revisions to existing CNSC documents as those documents aredeveloped or reaffirmed, and reflect advances in scientific and technical knowledge.
Suggestions for additions and revisions to the terms and definitions included in this document
should be submitted to the CNSC.

2

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2.

REGDOC-3.6, Glossary of CNSC Terminology

Terms and Definitions

A
A1, A2 (A1, A2)
Ha[ve] the same meanings as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: A1 and A2 are values specific to each radionuclide and are used to determine the activity limits fortransport packages.
abandon (abandonner)
Remove from regulatory control.
abiotic (abiotique)
Relating to the non-living parts of the environment such as air, rock, soil and water. Some abiotic
components are topography, hydrology, drainage, climate, meteorology, and land-use patterns bymembers of the public.
abnormal incident (incident anormal)
An abnormal occurrence that may have a significant cause and/or may lead to more serious consequences.
Aboriginal peoples of Canada (peuples autochtones du Canada)
Includes the Indian, Inuit and Métis peoples of Canada. (Source: Constitution Act, 1982)
Note: Outside of legal contexts, the term First Nations is used in place of the term Indian. See also
Indigenous peoples.
absent from duty (absent de son poste)
Not available on a day normally scheduled for duty.
absorbed dose (D) (dose absorbée [D])The quotient, in gray, obtained by dividing the energy absorbed through exposure to radiation by the massof the body or part of the body that absorbs the radiation. (Source: Radiation Protection Regulations)See also effective dose, equivalent dose.
acceptance criteria (critères d’acceptation)
With respect to nuclear facilities, specified bounds on the value of a functional or condition indicator used
to assess the ability of a structure, system or component to meet its design and safety requirements.
acceptance parameter (paramètre d'acceptation)
A plant parameter that characterizes plant response and has a defined acceptance criterion as a limit for
the acceptable range of values.
access control (contrôle de l’accès)
A system for allowing only approved individuals to have unescorted access to the security zone and for
ensuring that all other individuals are subject to escorted access.

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REGDOC-3.6, Glossary of CNSC Terminology

access denial (refus d’accès)
A denial of access to an adversary, through the exercise of sufficient force, to a vital area of a nuclear
facility until an offsite response force intervenes effectively.
accident (accident)
Any unintended event, including operating errors, equipment failures or other mishaps, the consequencesor potential consequences of which are significant from the point of view of protection or safety. With
respect to nuclear criticality safety, the term accidents or accident sequences means events or event
sequences, including external events, that lead to violation of the subcriticality margin (that is, toexceeding the upper subcritical limit).
accident conditions (conditions d’accident)
Deviations from normal operation more severe than anticipated operational occurrences. Accident
conditions include design-basis accidents and design extension conditions.
accident management (gestion des accidents)
The taking of a set of actions during the evolution of an accident to prevent the escalation of the accident,
to mitigate the consequences of the accident, and to achieve a long-term safe stable state after theaccident.
accidents or accident sequences (accidents ou séquences d’accident)
See accident.
account audit (vérification comptable)
An examination by IAEA or CNSC inspectors of the nuclear material accounts, records and reports at a
facility to check for completeness, correctness, internal consistency and consistency with the Member
State reports.
accounting (comptabilisation)
A system of records and reports that shows, for each material balance area (MBA), the inventory of
nuclear material and the changes in that inventory, including receipts into and transfers out of the MBA.
accounting records (relevés comptables)
A set of data kept at each facility or location outside facilities showing the quantity of each category of
nuclear material present, its distribution within the facility and any changes affecting it. For each materialbalance area, accounting records contain:• all inventory changes, so as to permit a determination of the book inventory at any time
• all measurement results that are used for determination of the physical inventory• all adjustments and corrections that have been made in respect of inventory changes, book inventories
and physical inventories
accredited laboratory (laboratoire agréé)With respect to drug testing for fitness for duty, a laboratory accredited by the Substance Abuse andMental Health Services Administration to analyze and report the results of urine drug specimen tests.
ACR (RAC)
annual compliance report4February 2023

REGDOC-3.6, Glossary of CNSC Terminology

Act (Loi)
The Nuclear Safety and Control Act. (Sources: All regulations pursuant to the Nuclear Safety and Control
Act)
Note: In this glossary, unless otherwise indicated, Act means the Nuclear Safety and Control Act. The
CNSC also uses “NSCA”, especially when distinguishing between two or more acts under discussion.
action level (seuil d’intervention)
A specific dose of radiation or other parameter that, if reached, may indicate a loss of control of part of alicensee’s radiation protection program and triggers a requirement for specific action to be taken.
(Source: Radiation Protection Regulations)OR
A specific dose of radiation or other parameter that, if reached, may indicate a loss of control of part of alicensee’s radiation protection program or environmental protection program, and triggers a requirement
for specific action to be taken. (Source: Uranium Mines and Mills Regulations)
Note 1: An action level is an indicator of a potential loss of control of part of a program and/or control
measure(s). An action level is said to be exceeded if it goes either above an upper limit or below a lower
limit, depending on the parameter being measured. Exceeding an action level signals, to both the licensee
and regulator, a potential reduction in the effectiveness of the program and/or control measure(s) and may
indicate a deviation from normal operation.
Note 2: Action levels are proposed by the licensee and submitted for review and approval by the CNSC.
Within the licensing basis for a specific site, action levels should be adjusted (subject to CNSC review
and approval) depending on changes to site activities or processes.
Note 3: Exceeding an action level triggers a requirement for a specific action to be taken. Exceeding anaction level is not considered a non-compliance; however, failure to respond appropriately is a
non-compliance. To respond to an exceedance, a licensee must follow:• the steps in subsection 6(2) of the Radiation Protection Regulations• requirements in the licensee’s code of practice, as set out under subsection 4(2) of the Uranium Minesand Mills Regulations• additional requirements that may be included in the licensee’s licensing basis
action notice (avis d’action)
A written request that a licensee or a person subject to enforcement action take steps to correct a
non-compliance that is not a direct contravention of the Nuclear Safety and Control Act, applicableregulations, licence conditions, codes or standards, but which can compromise safety, security or theenvironment and may lead to a direct non-compliance if not corrected.
active engineered nuclear criticality safety control (contrôle technique actif de sûreté-criticité
nucléaire)
See engineered (nuclear) criticality safety control.
active threat (incident en cours)
One or more adversaries who randomly or systematically inflict death or grievous bodily harm in a very
short period of time. Also called active shooter.
activity (activité)
The number of nuclear transformations occurring per unit of time, as measured in becquerels.
(Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
OR
See licensed activity.
OR5

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REGDOC-3.6, Glossary of CNSC Terminology

The condition of being active or moving about.
OR
A particular occupation or pursuit.
actual full cost (coût entier réel)
The full cost verified by audited financial statements. (Source: Canadian Nuclear Safety Commission
Cost Recovery Fees Regulations)
adaptive management (gestion adaptative)
A planned and systematic process for continuously improving management practices [primarily
environmental] by learning from their outcomes. [For an environmental assessment (EA),] it involves,
among other things, the implementation of new or modified mitigation measures over the life of a projectto address unanticipated environmental effects. (Source: Practitioners Glossary for the Environmental
Assessment of Designated Projects Under the Canadian Environmental Assessment Act, 2012 [1]).
Note: The need to implement adaptive management measures may be determined through an effective
follow-up program. See also corrective action.
additional safety feature (caractéristique de sûreté additionnelle)
See complementary design feature.
ad hoc bioassay (essai biologique ponctuel)See non-routine bioassay.
adjusted book ending (stock comptable final)
See book-adjusted ending.
administrative (nuclear) criticality safety control (contrôle administratif de sûreté-criticité[nucléaire])
Either an enhanced or simple administrative control:• enhanced administrative control: a procedurally required or prohibited human action, combinedwith a physical device that alerts an operator to take action to maintain safe process conditions, or that
otherwise adds substantial assurance of the required human performance• simple administrative control: a procedural human action that is prohibited or required to maintainsafe process conditions
administrative monetary penalty (AMP) (sanction administrative pécuniaire [SAP])
An administrative penalty imposed without court involvement in response to the violation of a regulatory
requirement. There is no criminal record associated with an AMP and an AMP can be applied against any
party subject to the Nuclear Safety and Control Act, including non-licensees.
adversary (adversaire)
A person performing malevolent acts in pursuit of interests harmful to the facility; an adversary may be
an insider or an outsider.
adverse information (renseignement défavorable)
Information about a site access security clearance (SASC) applicant or holder – whether collected by thelicensee, outside agencies or a trusted agent – that is questionable in nature, unclear or does not match theinformation provided by the applicant. The information collected may indicate:• a gap in history• a poor credit rating• a criminal conviction

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REGDOC-3.6, Glossary of CNSC Terminology

links to a criminal element
concerns related to the reliability or trustworthiness of a SASC applicant or holder

AECL (EACL)
Atomic Energy of Canada Limited
affected facilities (installations touchées)
Onsite locations under duress and the components, the affected facility/unit(s) and their components that
control, contain and cool nuclear substances and prevent the release of nuclear substances.
ageingSee aging.
aging (vieillissement)
The gradual change of the characteristics of a structure, system or component over time or with use.
Note: One or more mechanisms may drive physical aging. Physical aging is due to physical, mechanical,
thermal, electrical, chemical, irradiation and/or biological processes (aging mechanisms). Non-physicalaging means becoming out of date (obsolete) due to the evolution of knowledge and technology andassociated changes in codes and standards.
aging degradation (dégradation due au vieillissement)
Aging effects that could impair the ability of a structure, system or component to function within its
acceptance criteria.
aging effects (effets du vieillissement)
Net changes in the characteristics of a structure, system or component that occur with time or use and are
due to aging mechanisms.
aging management (AM) (gestion du vieillissement)
Engineering, operations, inspection and maintenance actions to control, within acceptable limits, theeffects of physical aging and obsolescence of structures, systems and components.
aging management program / aging management plan (AM program/plan) (programme ou plan degestion du vieillissement [programme ou plan de GV])
A set of policies, processes, procedures, arrangements and activities that provides direction for managing
the aging of a nuclear power plant’s structures, systems and components (SSCs). AM program refers to
the overall integrated aging management program or framework for a nuclear facility, while AM planrefers to a plan that is SSC specific or mechanistic based. Also called lifecycle management plan.
Note: The acronym AMP is now reserved for administrative monetary policy.
aging mechanism (mécanisme de vieillissement)
A specific process that, with time or use, gradually changes characteristics of a structure, system orcomponent. Some examples are thermal or radiation embrittlement, corrosion, fatigue, creep and erosion.
agitation (agitation)
The physical movement of Raschig glass rings relative to one another that may cause breakage or
gravitational settling.

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REGDOC-3.6, Glossary of CNSC Terminology

air kerma (kerma de l’air)
The kerma (kinetic energy released in matter) value for air, in gray, where kerma (K) is defined as:
dE
K = trdm
where dE tr is the sum of the initial kinetic energies of all charged ionizing particles liberated byuncharged ionizing particles in air of mass dm.
ALARA (ALARA)
See as low as reasonably achievable.
Alcohol Test Committee (Comité des analyses d’alcool)
A scientific committee, under the auspices of the Canadian Society of Forensic Science, that evaluates thescientific, technical and law enforcement aspects of breath alcohol. Note: Its scope includes roadsidescreening devices, automated breath test equipment, mobile breath testing and provisions to demand
blood samples.
ALI (LAI)
See annual limit on intake.
alpha counter (compteur de particules alpha)
An instrument designed and manufactured to detect and count alpha particle emissions.
alpha particle (particule alpha)A positively charged particle ejected spontaneously from the nuclei of some radioactive elements.
Note: An alpha particle is identical to a helium nucleus, which has a mass number of 4 and anelectrostatic charge of +2. An alpha particle has low penetrating power and a short range (a few
centimetres in air). Alpha particles will generally fail to penetrate the dead layers of cells covering theskin and can be easily stopped by a sheet of paper. However, alpha-emitting isotopes are harmful if
ingested.
alpha radiation (rayonnement alpha)Radiation consisting of alpha particles. See also alpha particle.
alternative activity limit for an exempt consignment (autre limite d’activité pour un envoi exempté)
In respect of an instrument or article, means an activity limit for a consignment that is above the activity
level for an exempt consignment set out in the IAEA Regulations and that has been approved as meetingthe exemption criteria set out in those Regulations for an instrument or article. (Source: Packaging andTransport of Nuclear Substances Regulations, 2015)
AM (GV)See aging management.
AM program / AM plan (programme ou plan de gestion du vieillissement [GV])
See aging management program / aging management plan.
AMP (SAP ou PGV)
See administrative monetary penalty or aging management program / aging management plan.
Note: The acronym AMP is now reserved for administrative monetary penalty.
analyst (analyste)
A person designated as an analyst under section 28. (Source: Nuclear Safety and Control Act)

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REGDOC-3.6, Glossary of CNSC Terminology

analytical decision level (niveau de décision analytique [niveau critique])
The amount of a count or final instrument measurement of a quantity of analyte at or above which a
decision is made that a positive quantity of the analyte is present (measured in becquerels per litre).
annual limit on intake (ALI) (limite annuelle d’incorporation [LAI])
The activity, in becquerel, of a radionuclide that will deliver an effective dose of 20 mSv during the
50-year period after the radionuclide is taken into the body of a person 18 years old or older or during theperiod beginning at intake and ending at age 70 after it is taken into the body of a person less than
18 years old. (Source: Radiation Protection Regulations)
ANO (ONA)
authorized nuclear operator; see reactor operator
ANS (ANS)
American Nuclear Society
ANSI (ANSI)
American Nuclear Standards Instituteanticipated operational occurrence (AOO) (incident de fonctionnement prévu [IFP])
An operational process deviating from normal operation that is expected to occur at least once during theoperating lifetime of a reactor facility but, because of appropriate design provisions, does not cause any
significant damage to items important to safety or lead to accident conditions. AOO is a plant state. Some
examples of AOO are loss of normal electrical power and faults such as a turbine trip, malfunction ofindividual items of a normally running plant, failure of individual items of control equipment to function,and loss of power to the main coolant pump.
AOO (IFP)
See anticipated operational occurrence.
applicant (demandeur)An organization or person that has applied to the CNSC for a licence or for certification. For example, anapplicant that applies for a licence to construct a nuclear facility has the overall responsibility, andcontrolling and coordinating authority, for overseeing the safe and satisfactory completion of all design,
procurement, manufacturing, construction and commissioning work.
ORAny person applying for a site access security clearance (SASC) to a high-security site in Canada.
Note: CNSC staff who are not inspectors and/or do not hold a Level II Secret Government of Canada
clearance will apply for a CNSC SASC to work at the licensed facility.
applicant authority (responsable de la demande)
A position within an applicant’s organizational structure with power to direct the application of financial
and human resources.
approved instrument (instrument approuvé)
With respect to breath samples, an instrument of a kind that is designed to receive and make an analysis
of a sample of a person’s breath in order to measure the concentration of alcohol in the blood of that
person, and which is approved as suitable for the purposes of section 258 of the Criminal Code by orderof the Attorney General of Canada.

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REGDOC-3.6, Glossary of CNSC Terminology

areal density (densité surfacique)
The product of the thickness of a uniform slab and the density of fissionable material within the slab;
hence, areal density is the mass of fissionable material per unit area of slab. Note: For non-uniform
slurries, the areal density limits are valid for a horizontal slab subject to gravitational settling, provided
the restrictions for uniform slurries are met throughout.
area(s) of applicability (domaine[s] d’applicabilité)
The limiting ranges of material compositions, geometric arrangements, neutron energy spectra and otherrelevant parameters (such as heterogeneity, leakage, interaction or absorption) within which the bias of acalculational method is established.
array (réseau)
Any fixed configuration of fissile or fissionable material units maintained by mechanical devices.
ASDV (VDVA)
atmospheric steam discharge valve
as-found condition (état observé)
The condition of an item when it was first found, received, inspected or otherwise designated for current
use, and prior to any subsequent corrective work being performed on the item (for example, cleaning,calibration, adjustment, servicing, repair or refurbishment).
as low as reasonably achievable (ALARA) (niveau le plus bas qu’il soit raisonnablement possibled’atteindre [ALARA])
A principle of radiation protection that holds that exposures to radiation are kept as low as reasonably
achievable, social and economic factors taken into account. Section 4 of the Radiation Protection
Regulations stipulates licensee requirements with respect to ALARA.
ASME (ASME)
A professional association, founded as the American Society of Mechanical Engineers.
assembly (assemblage)
See fissile assembly.
assessment (évaluation)
The process and the result of systematically evaluating the protection and safety measures, aimed atquantifying performance measures for comparison with criteria. Note: Assessment should be
distinguished from analysis. Assessment is aimed at providing information that forms the basis for
deciding whether or not something is satisfactory. Various kinds of analysis may be used as tools when
making an assessment; therefore, an assessment may include a number of analyses.
atom (atome)
The smallest particle of an element that cannot be divided or broken up by chemical means. The atom
consists of a central core (or nucleus), containing protons and neutrons, with electrons revolving in orbits
in the region surrounding the nucleus.
at power (exploitation normale)
An operational state characterized by the following conditions:• the reactor being critical• automatic actuation of safety systems not blocked• essential support systems aligned in their normal power configuration10

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REGDOC-3.6, Glossary of CNSC Terminology

authority having jurisdiction (AHJ) (autorité compétente (AC))
The regulatory organization, office or agency responsible for approving or accepting designs, equipment,materials, installations or procedures in accordance with applicable codes and standards.
Note 1: In Canada, the regulatory authorities are the Canadian Nuclear Safety Commission (CNSC) andother provincial or federal government agencies that have jurisdiction.
Note 2: the authority having jurisdiction is also referred to as the “regulatory authority”.
authorized access (accès autorisé)
Access that is granted in writing by the licensee.
authorized health physicist (spécialiste principal en radioprotection)
See senior health physicist.
authorized inspection agency (agence d’inspection autorisée)With respect to pressure boundaries, an organization designated by the authority having jurisdiction, as
authorized to register designs and procedures, perform inspections, and perform other defined functions
for pressure-retaining components.
authorized nuclear operator (ANO) (opérateur nucléaire autorisé [ONA])
See reactor operator.
availability (disponibilité)
The fraction of time that a component or system is able to function. Availability can also mean theprobability that a component or system will be able to function at any given time.

Bbackground radiation (rayonnement de fond)
The dose or dose rate (or an observed measure related to the dose or dose rate) attributable to all sources
other than the one specified.
back-out dose limit (limite de dose de marche arrière)
The predetermined dose limit that should prompt emergency responders to physically retreat from an area
and then assess the situation.
backup trip parameter (paramètre de déclenchement secondaire)
See primary and backup (secondary) trip parameter.
balance of the pregnancy (reste de la grossesse)
The period from the moment a licensee is informed, in writing, of the pregnancy to the end of thepregnancy. (Source: Radiation Protection Regulations)baseline criteria (critères de base)
A set of measurements (or metrics) representing the starting level of performance for a structure, systemor component. Baseline criteria are derived from design requirements and are usually established duringcommissioning and after replacement, overhaul or refurbishment.

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basic radionuclide value (valeur de base pour un radionucléide)Either an A1 in TBq, an A2 in TBq, an activity concentration limit for an exempt material in Bq/g or an
activity limit for an exempt consignment in Bq, as set out in the IAEA Regulations. (Source: Packaging
and Transport of Nuclear Substances Regulations, 2015)
Note: Bq/g means becquerels/gram; TBq means terabecquerels.
batch (lot)A portion of nuclear material handled as a unit for nuclear material accounting purposes at a key
measurement point. The composition and quantity are defined by a single set of specifications (material
description code) or measurements (concentration, enrichment). Note: The nuclear material may be inbulk form or contained in a number of separate items. Items included in a batch must contain nuclear
material of the same element concentration and enrichment. Items of different material description codes
must be reported as separate batches.
batch data (données concernant le lot)
The total weight of each element of nuclear material and its isotopic composition as applicable. See also
source data.
BATEA (MTEAR)
See best available technology and techniques economically achievable.
BDBA (AHD)
See beyond-design-basis accident.
BDBE (SHD)
beyond-design-basis earthquake
BDBT (MHD)
See beyond-design-basis threat.
BDCP (PCSE)
See by-difference correction principle.
BE (IA)
below expectations; see safety performance rating methodology
beam limiter (obturateur de faisceau)
A radiation-shielding device, located at the working position of an exposure device, which is designed toreduce the radiation dose rate in directions other than the direction intended for use. The beam limiter
may be designed to be used in conjunction with an exposure head or may incorporate an exposure head as
an integral part of the device. Also called collimator.
BEAU (BEAU)
See best estimate and uncertainty (BEAU) method.

12February 2023

REGDOC-3.6, Glossary of CNSC Terminology

becquerel (Bq) (becquerel [Bq])
The International System of Units (SI) unit of radioactivity. One becquerel (Bq) is the activity of aquantity of radioactive material in which one nucleus decays per second. In Canada, the Bq is usedinstead of the non-SI unit curie (Ci).
Note 1:
1 Bq = 27 pCi (2.7 x 10-11 Ci) and 1 Ci = 3.7 x 1010 Bq.
Note 2:
1 megabecquerel (MBq) = 106 Bq
1 gigabecquerel (GBq) = 109 Bq
1 terabecquerel (TBq) = 1012 Bq
below expectations (BE) (inférieur aux attentes [IA])See safety performance rating methodology.
benchmark experiment (valeur repère)With respect to nuclear criticality safety, a well-characterized experiment at the critical state that may be
used to establish the reliability of calculational methods.
best available technology and techniques economically achievable (BATEA) (meilleures techniques
existantes d’application rentable [MTEAR])
Minimum pollution prevention performance standards for controlling releases (effluents and/or
emissions) to the environment that have been demonstrated as achievable within a given industrial sector
and are therefore economically achievable across that sector. BATEA takes into account both treatment
technologies and techniques used to achieve the desired control. The way in which the installation isdesigned, built, maintained, operated and decommissioned is also considered as part of these technologies
and techniques. Note: BATEA may change over time as technologies and techniques are improved. As abest practice, BATEA should be regularly reviewed.
best estimate (meilleure estimation)
With respect to safety analysis, an unbiased estimate obtained by using a mathematical model, calculation
method or data to realistically predict behaviour and important parameters.
best estimate and uncertainty (BEAU) method (méthode de la meilleure estimation et des incertitudes[BEAU])An analysis that assumes more realistic initial and boundary conditions with all uncertainties (those
associated with assumptions, models and computer codes) defined to a high level of confidence.
best estimate method (méthode de la meilleure estimation)
A method designed to give realistic results.
best practice (pratique exemplaire)
An industry-accepted approach (for example, toward a design, process or procedure) that is
acknowledged as consistently producing superior results.
beta backscatter gauging (jaugeage de rétrodiffusion bêta [Beta Backscatter])
The use of beta-emitting nuclear substances incorporated in a radiation device to measure the thickness ofmaterial. The term is used as a licence use type.
beta particle (particule bêta)A charged particle that is emitted from the nucleus of a radioactive element during radioactive decay ofan unstable atom. Large amounts of beta radiation may cause skin burns, and beta emitters are harmful ifthey enter the body. Beta particles may be stopped by thin sheets of metal or plastic.

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REGDOC-3.6, Glossary of CNSC Terminology

beta radiation (rayonnement bêta)See beta particle.
beyond-design-basis accident (BDBA) (accident hors dimensionnement [AHD])
An accident less frequent and potentially more severe than a design-basis accident. Note: For a reactor
facility, a beyond-design-basis accident may or may not involve fuel degradation.
beyond-design-basis initiating event (événement déclencheur hors dimensionnement)
Any initiating event that is not considered in the design of the facility including external hazards that are
beyond the design basis such as large seismic loads, tsunamis, flooding by extreme high water level,
damage by extreme weather conditions (e.g., hurricanes, ice-rains, sandstorms, etc.), or man-made actions
or structures, such as airplane crashes, transport accidents, nearby chemical plants, gas pipes or riverdams.
beyond-design-basis threat (BDBT) (menace hors dimensionnement [MHD])
Threat conditions, more severe than a design-basis threat, that may result in structural degradation andmay involve confinement degradation.
bias (biais)
A measure of the systematic differences between calculational method results and experimental data.
Uncertainty arises from a systematic error that is known to cause deviation in a fixed direction.
bioassay (essai biologique)
The study of all living organisms to measure the effect of a substance, factor or condition by comparing
before-and-after exposure or other data. Note: Specific to radiation exposure in humans, bioassay is any
procedure used to determine the nature, activity, location or retention of radionuclides in a body by direct(in vivo) measurement or by indirect (in vitro) analysis of material excreted or otherwise removed from abody. In vivo bioassay may be referred to as direct bioassay; in vitro bioassay may be referred to as
indirect bioassay.
biokinetic model (modèle de biocinétique)
A mathematical description of the behaviour of radionuclides in the metabolic processes of cells, tissues,organs and organisms. The term is most frequently used to describe distribution of radionuclides among
tissues and excretion.
biota (biote)
All living organisms, including humans.
biotic (biotique)
Relating to the living parts of the environment: plants, animals and microorganisms. Biotic components
include any part of the environment considered important by the licensee, the general public, the scientificcommunity, the Government of Canada, and any environmentally sensitive habitat.
blinding (« en aveugle »)Conditions for which an actuation or conditioning signal is approached but not reached, either because of
the small magnitude of the initiating event or the actions of any other process or safety system.
block of consecutive shifts (bloc de quarts consécutifs)
Set of consecutive shifts with the same start and end times followed by a minimum recovery period and asubsequent set of consecutive shifts.

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REGDOC-3.6, Glossary of CNSC Terminology

boiler (générateur de vapeur)
See steam generator.
boiling water reactor (BWR) (réacteur à eau bouillante [REB])
A common type of light-water reactor, where water is allowed to boil in the core, generating steam
directly in the reactor vessel to generate electrical power.
book-adjusted ending (stock comptable final)
The algebraic sum of the beginning physical inventory and of the inventory changes of a material balancearea over a given period, adjusted to take account of shipper–receiver differences. Also called adjusted
book ending.
book inventory (stock comptable)
The algebraic sum for a given point in time of the most recent physical inventory of a material balancearea and all inventory changes that have occurred since that physical inventory was taken.
borehole tube tagging (marquage de tuyaux de sondage)
The use of nuclear substances placed subsurface or in equipment intended for subsurface use fordetermining borehole depth or direction. This term is used as a licence use type.
borescope (endoscope)
An inspection tool with a rigid or flexible optical tube designed for insertion into bores and cavities. The
borescope consists of a lens positioned in front of a long tube containing image and illumination relays.
boundary conditions (conditions aux frontières)The values of variables in a mathematical model that are assumed at the spatial bounds of the model.
bounding assessment (évaluation de délimitation)
An assessment designed to provide limiting or worst-case predictions, based on simplification of theprocesses being simulated or the use of data limits (such as maximum possible precipitation or
thermodynamic solubility limits).
bounding envelope (enveloppe limitative)
A combination of facility design parameters and site characteristics that establishes a set of limiting
values for any facility design that could be proposed for the site and that allows for the assessment ofenvironmental effects and site evaluation. Note: The design eventually selected must fit within thebounding envelope.
bounding event (événement limitatif)
The event with the smallest predicted margin to a specific acceptance criterion.
Bq (Bq)See becquerel.
brachytherapy machine (appareil de curiethérapie)
See brachytherapy remote afterloader.

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REGDOC-3.6, Glossary of CNSC Terminology

brachytherapy remote afterloader (appareil de curiethérapie à projecteur de source télécommandé)
A device that is designed to place, by remote control, a sealed source inside or in contact with a person fortherapeutic purposes and to remove, by remote control, the sealed source once a preset dose of radiation
has been delivered or after a preset time has elapsed. (Source: Class II Nuclear Facilities and Prescribed
Equipment Regulations)breath alcohol technician (éthylométriste)With respect to breath samples, a person who is qualified to operate an approved instrument. Also called
qualified technician. See also approved instrument.
Bremsstrahlung (rayonnement de freinage [Bremsstrahlung])
Electromagnetic radiation produced by the deceleration of a charged particle, such as an electron, when
deflected by another charged particle, such as an atomic nucleus.
buckling (flambage)
In engineering, a failure mode characterized by the sudden failure of a structural member (for example, acontainment shell) that is subjected to high compressive stresses, where the actual compressive stresses at
failure are smaller than the ones that the material is capable of withstanding. Also called failure due toelastic instability.
bulk form (matière en vrac)
Material such as a liquid, gas, powder, pellets or pebbles which, due to its containment, is not individually
identified for accounting purposes. Bulk form material may be contained in a tank, drum, tote or box.
bulk quantity (quantité en vrac)
Means, in respect of the terms “exemption quantity” and “unconditional clearance level”,(a) when referred to in section 5, a quantity of material greater than one tonne; and(b) when referred to in section 5.1, a quantity of material greater than one tonne per year per nuclear
facility.
(Source: Nuclear Substances and Radiation Devices Regulations)burnup (combustion nucléaire)
See fuel burnup.
BWR (REB)
See boiling water reactor.
by-difference correction principle (BDCP) (principe de correction selon l’écart [PCSE])
The principle by which a correction to an inventory change data element in a report is applied within thematerial balance period in which the change is dated. The weight difference between the original record
and the correcting record is recorded in the accounts (that is, general ledger) on the date the correction to
the inventory change is realized and recorded.

Ccalandria (calandre)
With respect to CANDU nuclear power plants, a cylindrical tank that houses the reactor’s fuel channels aswell as the moderator. See also calandria tube.

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REGDOC-3.6, Glossary of CNSC Terminology

calandria tube (tube de calandre)
With respect to CANDU nuclear power plants, one of a set of tubes that span the calandria and separate
the pressure tubes from the moderator. Each calandria tube contains one pressure tube, with an insulating
gas between the calandria tube and the pressure tube. See also calandria.
calculational method (méthode de calcul)
The calculational procedures – mathematical equations, approximations, assumptions, associatednumerical parameters (such as cross-sections) – that yield the calculated results.
calendar year (année civile)
A period of 12 consecutive months beginning on January 1.
calibration (étalonnage)
The process to verify that, with a known precision input, a model, instrument or channel parameter gives
the required output.
Canada/IAEA Safeguards Agreement (Accord relatif aux garanties entre le Canada et l’AIEA)
See IAEA Agreement or safeguards agreement.
Canadian Nuclear Safety Commission (CNSC) (Commission canadienne de sûreté nucléaire [CCSN])
Canada’s nuclear regulator, established under the Nuclear Safety and Control Act to regulate the use of
nuclear energy and materials to protect health, safety, security and the environment; to implement
Canada’s international commitments on the peaceful use of nuclear energy; and to disseminate objective
scientific, technical and regulatory information to the public.
Canadian Standards Association (CSA) (Association canadienne de normalisation [CSA])
See CSA Group.
CANDU reactor (réacteur CANDU)
A Canadian-invented pressurized heavy-water reactor that uses heavy water (deuterium oxide) for
moderator and coolant and natural uranium for fuel. “CANDU” is short for CANada Deuterium Uranium.
Also called CANDU.
carrier (transporteur)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)
CASA (ESAC)
criticality accident sequence assessment
catch-all controls (contrôles « fourre-tout »)See end-use controls.
Category I nuclear material (matière nucléaire de catégorie I)
A nuclear substance listed in column 1 of Schedule 1 that is in the corresponding form set out in column 2
and the corresponding quantity set out in column 3 of Schedule 1. (Source: Nuclear Security Regulations)
Note: Use Roman numerals for this term. Also note that categories for nuclear material do not have thesame meaning as categories for sources (compare to Category 1 source).

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REGDOC-3.6, Glossary of CNSC Terminology

Category 1 source (source de catégorie 1)
A sealed source that, if not safely managed or securely protected, would be likely to cause permanent
injury to a person who handled it, or was otherwise in contact with it, for more than a few minutes. It
would probably be fatal to be close to this amount of unshielded radioactive material for a period of a few
minutes to an hour. In Canada, these sources are typically used in practices such as self-shielded
irradiators and radiation teletherapy. Note: Use Arabic numerals for this term. Also note that categories
for sources do not have the same meaning as categories for nuclear material (compare to Category I
nuclear material).
Category II nuclear material (matière nucléaire de catégorie II)
A nuclear substance listed in column 1 of Schedule 1 that is in the corresponding form set out in column 2
and the corresponding quantity set out in column 4 of Schedule 1. (Source: Nuclear Security Regulations)
Note: Use Roman numerals for this term. Also note that categories for nuclear material do not have thesame meaning as categories for sources (compare to Category 2 source).
Category 2 source (source de catégorie 2)
A sealed source that, if not safely managed or securely protected, could cause permanent injury to aperson who handled it, or was otherwise in contact with it, for a short time (minutes to hours). It could
possibly be fatal to be close to this amount of unshielded radioactive material for a period of hours todays. In Canada, these sources are typically used in practices such as industrial gamma radiography andoil well logging. Note: Use Arabic numerals for this term. Also note that categories for sources do nothave the same meaning as categories for nuclear material (compare to Category II nuclear material).
Category III nuclear material (matière nucléaire de catégorie III)
A nuclear substance listed in column 1 of Schedule 1 that is in the corresponding form set out in column 2
and the corresponding quantity set out in column 5 of Schedule 1. (Source: Nuclear Security Regulations)
Note: Use Roman numerals for this term. Also note that categories for nuclear material do not have thesame meaning as categories for sources (compare to Category 3 source).
Category 3 source (source de catégorie 3)
A sealed source that, if not safely managed or securely protected, could cause permanent injury to aperson who handled it, or was otherwise in contact with it, for some hours. It could possibly – although it
is unlikely – be fatal to be close to this amount of unshielded radioactive material for a period of days toweeks. In Canada, these sources are typically used in practices such as fixed nuclear gauges and high dose
rate brachytherapy. Note: Use Arabic numerals for this term. Also note that categories for sources do nothave the same meaning as categories for nuclear material (compare to Category III nuclear material).
Category 4 source (source de catégorie 4)
A sealed source that is very unlikely to permanently injure anyone. However, this amount of unshieldedradioactive material, if not safely managed or securely protected, could possibly – although it is unlikely –temporarily injure someone who handled it or was otherwise in contact with it, or who was close to it fora period of many weeks. In Canada, these sources are typically used in practices such as portable nuclear
gauges. Note: Use Arabic numerals for this term. Also note that categories for sources do not have thesame meaning as categories for nuclear material (compare to Category I nuclear material, Category II
nuclear material and Category III nuclear material).

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REGDOC-3.6, Glossary of CNSC Terminology

Category 5 source (source de catégorie 5)
A sealed source that could not permanently injure someone. In Canada, these sources are typically used inpractices such as low dose rate brachytherapy or in gas chromatography instruments. Note: Use Arabic
numerals for this term. Also note that categories for sources do not have the same meaning as categories
for nuclear material (compare to Category I nuclear material, Category II nuclear material, andCategory III nuclear material).
category change (changement de catégorie)
A change in one of the three categories of uranium: depleted uranium, natural uranium and enricheduranium. Category change results in the reduction of one category of uranium and a corresponding
increase in another. Uranium can change category as a result of blending, enrichment, depletion or
burnup. For example, natural uranium can become depleted uranium as a result of the burnup of
uranium-235.
CCF (DCC)
See common-cause failure.
CCME (CCME)
Canadian Council of Ministers of the Environment
CEAA 2012 (LCEE 2012)
Canadian Environmental Assessment Act, 2012
CEDO (OAEA)
See certified exposure device operator.
CEPA (LCPE)
Canadian Environmental Protection Act, 1999
CEPA toxic (substance toxique au sens de la LCPE)
Has the meaning in section 64 of the Canadian Environmental Protection Act, 1999.
certificate (attestation; voir aussi homologation ou document d’homologation)
A document issued by the Commission or by a designated officer authorized under paragraph 37(2)(b) of
the Act, indicating that a person is certified. (Source: Class I Nuclear Facilities Regulations)OR
A document issued by the Commission or by a designated officer authorized under paragraph 37(2)(a) of
the Act, indicating that a model of Class II prescribed equipment is certified, or authorized underparagraph 37(2)(b) of the Act, indicating that a person is certified. (Source: Class II Nuclear Facilities
and Prescribed Equipment Regulations)OR
A document issued by the Commission or by a designated officer authorized under paragraph 37(2)(a) or(b) of the Act, indicating that prescribed equipment or a person is certified. (Source: Nuclear Substances
and Radiation Devices Regulations)OR
A document issued by the Commission under paragraph 21(1)(h) of the Act or by a designated officer
authorized under paragraph 37(2)(a) of the Act, indicating the certification of:(a) a package design;(b) a design for special form radioactive material;(c) a design for low dispersible radioactive material;

19February 2023

REGDOC-3.6, Glossary of CNSC Terminology(d) the calculation of a value demonstrating that fissile-excepted radioactive material will remain
subcritical;(e) the calculation of the basic radionuclide value for radioactive material that has a basic radionuclide
value that is not listed in the IAEA Regulations; or(f) the calculation, for an instrument or article that has an alternative activity limit for an exempt
consignment, of the alternative activity limit.
(Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
certification (accréditation)
A written attestation from the Commission, or from a designated officer authorized by it, that a person isqualified to carry out licensed activities (including the duties of a given position referred to in a licence).
certified (homologué)
Certified by the Commission under paragraph 21(1)(i) of the Act or by a designated officer authorizedunder paragraph 37(2)(b) of the Act. (Source: Class I Nuclear Facilities Regulations)OR
Certified by the Commission under paragraph 21(1)(h) or (i) of the Act or by a designated officer
authorized under paragraph 37(2)(a) or (b) of the Act. (Sources: Class II Nuclear Facilities andPrescribed Equipment Regulations; Nuclear Substances and Radiation Devices Regulations; Packaging
and Transport of Nuclear Substances Regulations, 2015)
certified exposure device operator (CEDO) (opérateur d’appareil d’exposition accrédité)
A person who has the qualifications to safely operate industrial gamma radiography exposure devices
anywhere in Canada and who is certified as such by the CNSC.
CFSI (ACFS)
counterfeit, fraudulent and suspect items; see also counterfeit item; fraudulent item; suspect item.
change (modification)
With respect to dosimetry information, any change to that information, such as a decrease or increase toan assigned dose value previously filed with the National Dose Registry. Normally, changes to dosimeter
wearing periods are not included as a modification to dosimetry information.
CHF (densité de flux thermique critique)critical heat flux
Ci (Ci)curie; see becquerel
Class I nuclear facility (installation nucléaire de catégorie I)
A Class IA nuclear facility and a Class IB nuclear facility. (Source: Class I Nuclear Facilities
Regulations)Class IA nuclear facility (installation nucléaire de catégorie IA)
Any of the following nuclear facilities:(a) a nuclear fission or fusion reactor or subcritical nuclear assembly; and(b) a vehicle that is equipped with a nuclear reactor.
(Source: Class I Nuclear Facilities Regulations)20February 2023

REGDOC-3.6, Glossary of CNSC Terminology

Class IB nuclear facility (installation nucléaire de catégorie IB)
Any of the following nuclear facilities:(a) a facility that includes a particle accelerator, other than a particle accelerator described inparagraphs (d) and (e) of the definition “Class II prescribed equipment” in section 1 of the Class II
Nuclear Facilities and Prescribed Equipment Regulations;(b) a plant for the processing, reprocessing or separation of an isotope of uranium, thorium or plutonium;(c) a plant for the manufacture of a product from uranium, thorium or plutonium;(d) a plant, other than a Class II nuclear facility as defined in section 1 of the Class II Nuclear Facilities
and Prescribed Equipment Regulations, for the processing or use, in a quantity greater than 1015 Bq
per calendar year, of nuclear substances other than uranium, thorium or plutonium;(e) a facility for the disposal of a nuclear substance generated at another nuclear facility; and(f) a facility prescribed by paragraph 19(a) or (b) of the General Nuclear Safety and Control
Regulations.
(Source: Class I Nuclear Facilities Regulations)Class II nuclear facility (installation nucléaire de catégorie II)
A facility that includes Class II prescribed equipment. (Source: Class II Nuclear Facilities and Prescribed
Equipment Regulations)Class II prescribed equipment (équipement réglementé de catégorie II)[Any of the following:](a) an irradiator that uses more than 1015 Bq of a nuclear substance;(b) an irradiator that requires shielding which is not part of the irradiator and that is designed to deliver adose of radiation at a rate exceeding 1 cGy/min at a distance of 1 m;(c) a radioactive source teletherapy machine;(d) a particle accelerator that is capable of producing nuclear energy and has a beam energy of less than
50 MeV for beams of particles with a mass equal to or less than 4 atomic mass units;(e) a particle accelerator that is capable of producing nuclear energy and has a beam energy of no morethan 15 MeV per atomic mass for beams of particles with a mass greater than 4 atomic mass units; or(f) a brachytherapy remote afterloader.
(Source: Class II Nuclear Facilities and Prescribed Equipment Regulations)
Note: The abbreviation cGy/min means centigray per minute. MeV means megaelectron volts.
Class II prescribed equipment certificate (homologation d’équipement réglementé de catégorie II)
A document issued by the Commission or by a designed officer authorized under the Nuclear Safety andControl Act, indicating that a model of Class II prescribed equipment is certified for use.
Clean-up activities (nettoyage)
With respect to decommissioning, means the removal of contaminated soil from an area within theboundary of a facility, location or siteclean waste rock (stériles propres)Rock without the potential to release hazardous and/or nuclear substances that could have a significant
adverse effect on human health or harm the environment. Clean rock may still require management forother reasons, such as to control erosion to prevent deposits of sand in local surface water bodies.

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REGDOC-3.6, Glossary of CNSC Terminology

clearance level (niveau de libération)
With respect to radioactivity levels, the maximum permissible concentrations of radioactivity in or on
materials, equipment and sites to be released from regulatory control (for example, becquerels per gramor per square centimetre, near-contact dose rates). Clearance levels may be expressed as conditional or
unconditional, depending on whether the specific pathways of release, or destinations for reuse, recycling
and/or disposal are specified.
cliff-edge effect (effet de falaise)
A small change of conditions that may lead to a catastrophic increase in the severity of consequences.
Note: Cliff-edge effects can be caused by changes in any of the following: environment characteristics,
the event or the facility response.
closure (FRENCH)
See decommissioning.
CM (gestion de la configuration)
See configuration management or corrective maintenance.
CMD (CMD)
See Commission member document.
CNS (CSN)
Convention on Nuclear Safety
CNSC (CCSN)
See Canadian Nuclear Safety Commission.
CNSC nuclear criticality safety requirements (exigences de sûreté-criticité nucléaire de la CCSN)
Regulatory requirements and derived acceptance criteria that are related to nuclear criticality safety andlisted in operating licence conditions or other legally enforceable documents.
code 10 (code 10)
Chapter 10 of the subsidiary arrangements of the Canada/IAEA Safeguards Agreement.
code accuracy (exactitude des programmes)
The degree of closeness of a calculated quantity to its actual value. Code accuracy comprises the bias andvariability of bias of a computer code that are derived from the comparison of code predictions withexperimental data.
collimator (collimateur)
See beam limiter.
combustion (combustion)
A chemical process that involves oxidation sufficient to produce heat or light.

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REGDOC-3.6, Glossary of CNSC Terminology

Commission (Commission)
The Canadian Nuclear Safety Commission established by section 8. (Source: Nuclear Safety and Control
Act)
Note 1: The Commission consists of not more than seven members, appointed by the Governor inCouncil, to:• make independent, fair and transparent decisions on the licensing of nuclear-related activities• establish legally binding regulations• set regulatory policy direction on health, safety, security and environmental issues affecting theCanadian nuclear sector
Note 2: This term is not used when the intention is to refer to both Commission members and CNSC
staff. See also Canadian Nuclear Safety Commission.
Commission member document (CMD) (document à l’intention des commissaires [CMD])
A document prepared for Commission hearings and meetings by CNSC staff, proponents and intervenors.
Commission Tribunal (tribunal de la Commission)
A term previously used to refer to the Commission. See Commission.
commissioning (mise en service)
With respect to a reactor facility, a process intended to demonstrate that installed structures, systems andcomponents (SSCs) perform in accordance with their specifications before the facility is placed in service
or before the SSCs are returned or placed in service.
commissioning documentation (documentation sur la mise en service)
The plans, instructions, procedures, drawings, reviews, records, reports and the like, which together
describe the commissioning of one or more structures, systems or components, or of the integrated reactor
facility.
commissioning report (rapport de mise en service)
A report written on completion of commissioning activities to record results, assess compliance with theacceptance criteria, and record actions taken to rectify any deficiencies.
commissioning test (essai de mise en service)
Pre-service testing to demonstrate that structures, systems and components perform within their design
specifications.
committed (engagée)
In respect of a dose of radiation, received by an organ or tissue from a nuclear substance during the
50 years after the substance is taken into the body of a person 18 years old or older or during the period
beginning at intake and ending at age 70, after it is taken into the body of a person less than 18 years old.
(Sources: Radiation Protection Regulations; Packaging and Transport of Nuclear Substances
Regulations, 2015)
common cause (cause commune)
See common-cause failure.
common-cause event (événement de cause commune)
An event that leads to common-cause failures.

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REGDOC-3.6, Glossary of CNSC Terminology

common-cause failure (CCF) (défaillance de cause commune [DCC])
A failure of two or more structures, systems, or components due to a single specific event or cause, suchas a natural phenomenon (earthquake, tornado, flood, etc.), design deficiency, manufacturing flaw,
operation and maintenance error, human-induced destructive event, or aging effect.
complementary design feature (caractéristique de conception complémentaire)
A design feature added to the design as a standalone structure, system or component (SSC) or added
capability to an existing SSC to cope with design extension conditions. Also called additional safety
feature.
complementary indicator (indicateur complémentaire)
A performance or safety indicator that is not specified by legislation or regulation and is not a direct
measure of performance or safety (safety indicators), but is used to complement the use of these more
direct indicators. Note: Complementary indicators are often intermediate parameters from which
performance or safety indicators can be derived, but are easier to calculate and monitor (for example,
concentration of contaminant releases as a complementary indicator to human exposure to that
contaminant). Complementary indicators can be useful in scoping calculations.
compliance (conformité)
Conformity by regulated persons or organizations with the requirements of the Nuclear Safety andControl Act (NSCA), the regulations made under the NSCA, and licences, decisions, certificates andorders made by the CNSC.
compliance assessment (évaluation de la conformité)
Verification activities mostly limited to the review of licensees’ documents and reports. Some examples
are quarterly technical reports, annual compliance reports, special reports and documentation related todesign, safety analysis, programs and procedures.
concentrate (concentré)
An extracted product that contains uranium and that results from the physical or chemical separation of
uranium from ore. (Source: Uranium Mines and Mills Regulations)
Note: See also uranium concentrate.
conditional clearance level (niveau de libération conditionnelle)
An activity concentration that does not result in an effective dose(a) greater than 1 mSv in a year due to a low probability event referred to in the IAEA Safety Standard
RS-G-1.7 [2]; or(b) greater than 10 µSv in a year.
(Source: Nuclear Substances and Radiation Devices Regulations)
Note: The abbreviation µSv means microsievert.
condition assessment (évaluation de l’état)An assessment performed to determine the current performance and condition of a structure, system orcomponent (SSC) (including any age-related failures or indications of significant material degradation),and to predict the future performance, extent and rate of aging degradation, and residual service life of the
SSC.
condition-based maintenance (entretien basé sur l’état constaté)
Maintenance that is planned and performed after identification or diagnosis of a structure, system orcomponent degradation, but before failure occurs. See also predictive maintenance.

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REGDOC-3.6, Glossary of CNSC Terminology

condition-based servicing (entretien basé sur l'état constaté)
See condition-based maintenance.
condition indicator (indicateur de l’état)A characteristic of a structure, system or component (SSC) that can be observed, measured or trended toinfer or directly indicate the SSC’s current and future ability to function within acceptance criteria.
condition monitoring (surveillance de l’état)Continuous or periodic inspections, measurements or trending of the performance or physicalcharacteristics of structures, systems and components, to indicate current or future performance and thepotential for failure.
configuration management (CM) (gestion de la configuration)
The process of identifying and documenting the characteristics of a facility’s structures, systems andcomponents (including computer systems and software), and of ensuring that changes to thesecharacteristics are properly developed, assessed, approved, issued, implemented, verified, recorded andincorporated in the facility documentation.
confinement boundary (enceinte de confinement)
A continuous boundary without openings or penetrations, which prevents the release of radioactive
materials out of the enclosed space.
Note 1: For small or research reactors, confinement, or confinement boundary, is the equivalent of apower reactor containment boundary but does not have significant pressure-retaining capability.
Note 2: For packaging and transport of nuclear substances, confinement means preserving criticality
safety, and containment means containing radioactive material.
confinement system (système d’isolement)
The assembly of fissile material and packaging components intended to preserve criticality safety.
(Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
Note: For reactor facilities, see confinement boundary.
conservatism (prudence)
The use of assumptions that make predictions regarding consequences more severe than if best-estimate
assumptions had been used.
conservative calculations (calculs conservateurs)
Calculations that are designed to over-predict a parameter with the intention that the reality will not begreater than the prediction. These calculations can be based on simplifications of the processes being
simulated (the structure of a model) or on limits of data values used in the model.
conservative method (méthode prudente)
A method deliberately leading to results that are intended to be limiting relative to specified acceptancecriteria.
consignee (destinataire)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: In the IAEA Regulations, consignee means any person, organization or government that is entitled
to take delivery of a consignment.

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consignment (envoi)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
consignor (expéditeur)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)
construction (construction)
The process of procuring, manufacturing and assembling the components, carrying out civil work,
installing and maintaining components and systems, and performing associated tests.
construction organization (organisation chargée de la construction)
The entity managing the procurement, manufacture and assembly of components, carrying out of civil
work, installment and maintenance of components and systems, and performance of associated tests. They
may be part of the licensee’s organization or a contracted entity.
construction safety case (dossier de sûreté pour la construction)
The information provided with the licence application for a licence to construct, including the documents
to which the application makes reference, once approved by the CNSC.
containment (confinement)
A method or physical structure designed to prevent or control the release of nuclear, radioactive or
hazardous substances. Some examples are:• for waste management: a barrier system that controls releases to the environment through different
chemical and physical applications• for reactor facilities: see containment structure• for deep geological disposal: the functions of both the natural barrier (such as the host rock) and theengineered barrier to limit radionuclide releases
OR
With respect to safeguards, means the structural features of a facility, containers or equipment that areused to establish the physical integrity of an area or items (including safeguards equipment or data) and tomaintain the continuity of knowledge of the area or items through the prevention of undetected access to,or movement of, nuclear or other material, or interference with the items.
OR
The exercise of force that is sufficient to isolate, contain and/or stop an adversary in order to prevent thetheft of nuclear material or sabotage to a vital area until the offsite response force can make an effective
intervention.
containment envelope (enceinte de confinement)
Structures and components that provide a pressure-retaining barrier to prevent or limit the escape of any
radioactive matter that could be released from a nuclear reactor.
containment structure (structure de confinement)
For reactor facilities, a physical structure designed to prevent uncontrolled release and dispersion of
nuclear substances.

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containment system (enveloppe de confinement)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
OR
See containment structure.
contaminant of potential concern (COPC) (contaminant potentiellement préoccupant [CPP])
Contaminant that could be released to the environment as a result of a project and that may change one ormore of the environmental components (atmospheric, aquatic, terrestrial).
contamination (contamination)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: More generally, contamination refers to nuclear or hazardous substances on surfaces, or withinsolids, liquids or gases (including the human body), where their presence is unintended or undesirable, orto the process giving rise to their presence in such places.
contamination meter (contaminamètre)A radiation detection instrument designed to measure surface contamination; this meter is not designed tomeasure radiation dose or dose rate.
contingency plan (plan d’urgence)
Predefined sets of actions for response to unauthorized acts indicative of attempted unauthorized removal
or sabotage, including threats thereof, designed to effectively counter such acts.
continuing training (formation continue)
A structured curriculum that maintains and enhances knowledge, skills and safety-related attributes, andthat addresses areas such as equipment changes and procedure changes, skill weaknesses, infrequently
used and difficult-to-acquire knowledge and skills, and lessons learned from operating experiences.
Refresher training, requalification training and update training are also considered continuing training.
contractor (sous-traitant)See vendor/contractor.
control (contrôle)
See environmental control.
control adapter (adaptateur de commande)
For exposure devices, a component of a control assembly that attaches the control assembly to the
exposure container.
control assembly (assemblage de commande)See remote control.
control cable connector (raccord du câble de commande)
For exposure devices, a component used to attach a drive cable to a source assembly.
control cable (drive cable) (câble de commande)
For exposure devices, a cable or other mechanical means used to push out or retract a sealed source
assembly in an exposure container by remote control.

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control cable sheath (gaine du câble de commande)
For exposure devices, the rigid or flexible tube for guiding a control cable by remote control to the
exposure container and for providing physical protection to the control cable.
controlled area (zone contrôlée)See restricted area.
controlled nuclear equipment (équipement nucléaire contrôlé)
The controlled nuclear equipment and the parts and components for controlled nuclear equipment referred
to in the schedule. (Source: Nuclear Non-proliferation Import and Export Control Regulations)See also nuclear and nuclear-related dual-use items.
controlled nuclear information (renseignement nucléaire contrôlé)
The controlled nuclear information referred to in the schedule. (Source: Nuclear Non-proliferation Importand Export Control Regulations)See also nuclear and nuclear-related dual-use items.
controlled nuclear substance (substance nucléaire contrôlée)A controlled nuclear substance referred to in the schedule. (Source: Nuclear Non-proliferation Import andExport Control Regulations)See also nuclear and nuclear-related dual-use items.
controlled parameter (paramètre contrôlé)
A parameter that is kept within specified limits, and, when varied, influences the margin of subcriticality.
controller (contrôleur)A person who, during an emergency drill or exercise, provides data and messages to the emergency
responders, for example, to ensure that the sequence of events is unfolding as per the scenario.
control location (lieu de commande)
A location that is permanently staffed during periods when an event may occur; for example, a control
room.
control mechanism (mécanisme de commande)See remote control.
control Raschig rings (controlled sample) (anneaux Raschig de contrôle [échantillon contrôlé])Raschig rings that are periodically removed from service for scheduled measurements and then returned
to service after these short test periods.
control room operator (CRO) (opérateur de salle de commande [OSC])
See reactor operator.
control room shift supervisor (chef de quart de salle de commande)
The person in a multi-unit nuclear power plant who is responsible to the plant shift supervisor for
ensuring that the main control room staff function safely within his or her authority limits and that the
conduct of operations within the main control room is performed in accordance with the plant’s licence,
policies and procedures.

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conventional health and safety SCA (santé et sécurité classiques [DSR])
A safety and control area (SCA) that covers the implementation of a program to manage workplace safety
hazards and to protect workers. This SCA is one of the 14 within the CNSC SCA Framework.
conventionally true value (valeur conventionnellement vraie)
The value attributed to a particular quantity and accepted, sometimes by convention, as having an
uncertainty appropriate for a given purpose. For example, the conventionally true value of Hp(d) is
established by measuring the free-in-air kerma (or exposure) in a well-defined field with a calibrated
instrument and then applying a conversion coefficient to the result. Sometimes also called best estimate;conventional value; reference value.
conventional value (valeur conventionnelle)
See conventionally true value.
conversion training (formation de conversion)
With respect to fitness for duty, additional training required for a breath alcohol technician who waspreviously qualified to operate an approved instrument, in order to qualify the technician to operate a
different approved instrument. See also approved instrument; breath alcohol technician.
conveyance (moyen de transport)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
COPC (CPP)
See contaminant of potential concern.
core control processes (processus de contrôle de base)
A functional area that groups 8 of the 14 safety and control areas (SCAs) within the CNSC SCA
Framework: radiation protection, conventional health and safety, environmental protection, emergency
management and fire protection, waste management, security, safeguards and non-proliferation, andpackaging and transport. Other functional areas are “management” and “facility and equipment”.
core damage (dommage au cœur)Accident leading to significant fuel degradation. For CANDU reactors, core degradation is defined as
extensive physical damage of the multiple fuel channels due to overheating leading to loss of core
structural integrity.
core damage frequency (fréquence des dommages au cœur)An expression of the likelihood that an accident could cause core damage.
corium (corium)
A lava-like molten mixture of portions of nuclear reactor core.
corrective action (mesure corrective)
Measure taken to eliminate the cause of a detected nonconformity or other undesirable situation toprevent recurrence. See also adaptive management.
corrective maintenance (CM) (entretien correctif)
Actions that, by means of repair, overhaul or replacement, restore the capability of a failed structure,system or component to perform its defined function within the given acceptance criteria.

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counterfeit item (article contrefait)
An item that is intentionally manufactured or altered to imitate a product without the manufacturer ormodifier having the legal right to do so.
country of obligation (pays émetteur d’obligations)
The country with which Canada has agreed to accept conditions on the use of the nuclear material
received from that country. Note: The country of obligation is not necessarily the country of origin or of
supply. The countries of obligation, origin and supply may all be different. For a given quantity of nuclear
material, there may be a single country of obligation, multiple countries of obligation, or no foreign
obligation. Material that has no specified obligations is referred to as unobligated.
country of origin (pays d’origine)
The country where specified nuclear material was mined.
country of supply (pays du fournisseur)
The country from which specified nuclear material was shipped prior to entering Canada.
cranking mechanism (mécanisme à manivelle)
See remote control.
crawler control (commande de chenille [crawler])
The use of sealed sources to remotely direct the movement of an industrial radiography pipeline crawler
unit.
CRDM (mécanisme d’entraînement de la barre de commande)
control rod drive mechanism
credible abnormal conditions (conditions anormales crédibles)
Accidents or accident sequences that have a frequency of occurrence equal to or more than one in a
million years. This definition applies specifically to nuclear criticality safety.
credible abnormal event (événement anormal crédible)
As defined in the CSA Group publication CSA N292.1, Wet Storage of Irradiated Fuel and OtherRadioactive Materials [13], a naturally occurring or human-generated event or event sequence that has afrequency of occurrence equal to or greater than 10-6 per year.
crediting (validation)
For a safety analysis, assuming the correct operation of a structure, system or component, or correct
operator action.
criminal records name check (CRNC) (vérification nominale du casier judiciaire (VNCJ)
A search used to determine if a person has a criminal record. The search can be based on name and dateof birth or, for much greater assurance, on fingerprints for positive identification.
critical component (composant critique)For exposure devices, a component that is essential to the safe operation of the device, in order to preventa misconnect or disconnect.
OR
Equipment whose failure will result in complete system failure or functional failure.

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critical group (groupe critique)A uniform or reasonably homogeneous group of people whose characteristics (such as habits, location orage) cause them to be representative of the more highly exposed individuals, receiving the highest
effective dose or equivalent dose (as applicable) than other groups in the exposed population.
criticality (criticité nucléaire)
See nuclear criticality.
criticality accident (accident de criticité)
The release of energy as a result of accidental production of a self-sustaining or divergent neutron chain
reaction.
criticality safety control (CSC) (contrôle de sûreté-criticité [CSC])
See nuclear criticality safety control.
criticality safety index (CSI) (indice de sûreté-criticité [CSI ou ISC])
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
criticality safety staff (personnel de sûreté-criticité)
See nuclear criticality safety staff.
CRNC (VNCJ)
See criminal records name check.
CRO (OSC)
control room operator; see reactor operator
CSA (CSA)
See CSA Group.
CSA Group (Groupe CSA)
A standard-setting body that works with the regulator, industry and stakeholders to produce consensusbased Canadian industry standards that may be used by the regulator or industry. Formerly called
Canadian Standards Association.
CSC (CSC)
See nuclear criticality safety control.
CSDV (SEVC)
condenser steam discharge valve
CSI (CSI)
See criticality safety index.
curie (curie)
See becquerel.
CVC (CVC)
compliance verification criteria

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cyber security (cybersécurité)Protection of digital computer-based systems or components throughout the system’s lifecycle fromthreats and malicious actions, or from inadvertent actions that result in unintended consequences. Cyber
security includes protection from unauthorized, unintended and unsafe modifications to the system, andfrom unauthorized disclosure and retention of information, software or data associated with the systemthat could be used to perform malicious or misguided acts that could affect the functionality andperformance of the system.
cyclotron (cyclotron)
A particle accelerator that speeds up particles in a circular motion until they hit a target at the perimeter ofthe cyclotron. Some cyclotrons are used to produce medical isotopes.

D
D (D)See absorbed dose.
DA (AD)
See derived activity.
DAC (LDCA)
See derived air concentration.
dangerous occurrence (situations dangereuses)
Any of the following situations:(a) a conveyance carrying radioactive material is involved in an accident;(b) a package shows evidence of damage, tampering or leakage of its contents, or its integrity is degradedin a manner that may reasonably be expected to impair its ability to comply with [the Packaging andTransport of Nuclear Substances Regulations, 2015 (PTNSR 2015)] or its certificate;(c) radioactive material is lost, stolen or no longer in the control of a person who is required to havecontrol of it under the [Nuclear Safety and Control Act (NSCA)];(d) radioactive material has escaped from a containment system, a package or a conveyance duringtransport;(e) fissile material is outside the confinement system during transport;(f) the level of non-fixed contamination, as defined in the IAEA Regulations, during transport exceeds
the following limits as applicable when averaged over any area of 300 cm2 of any part of the surfaceof the package or the conveyance:i.
4 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, orii.
0.4 Bq/cm2 for all other alpha emitters;(g) there is a failure to comply with the provisions of [the NSCA], the provisions of [the PTNSR 2015] or
any licence or certificate that is applicable to a package that may reasonably be expected to lead to asituation in which the environment, the health and safety of persons, or national security is adversely
affected.
(Source: Packaging and Transport of Nuclear Substances Regulations, 2015, section 35)
data element (élément de données)With respect to nuclear material accounting, a unit of information in material balance area records.
date of filing (of a report) (date de dépôt [d’un rapport])
The date on which a report is received by the Commission.

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day (jour)With respect to reporting requirements, a term that varies according to the contexts described in theInterpretation Act, sections 27 and 28, and subsection 35(1).
DBA (AD)See design-basis accident.
DBE (SR)See design-basis earthquake.
DBT
See design-basis threat.
DCF (FCD)
See dose conversion factor.
DEC (CAD)
See design extension conditions.
decommissioning (déclassement)
Administrative and technical actions taken to allow the removal of some or all of the regulatory controls
from a facility, location or site where nuclear substances are managed, used, possessed or stored.
Note: Decommissioning actions are the procedures, processes and work activities (such as storage withsurveillance, decontamination, dismantling or cleanup) that are taken to retire a facility, location or sitefrom service with due regard for the health and safety of people and the environment. For disposal
facilities, with the exception of ancillary facilities, the term “closure” instead of “decommissioning” isused. See also cleanup activities; decontamination; dismantle; storage with surveillance.
decontamination (décontamination)
The complete or partial removal of contamination by a deliberate physical, chemical or biologicalprocess.
deep geologic repository (dépôt géologique en profondeur [DGP])
See deep geological repository.
deep geological repository (DGR) (dépôt géologique en profondeur [DGP])
A facility where radioactive waste is placed in a deep, stable geological formation (usually several
hundred metres or more below the surface). The facility is engineered to isolate and contain radioactive
waste to provide the long-term isolation of nuclear substances from the biosphere. Also called deep
geologic repository. See also isolation.
defence in depth (défense en profondeur)A hierarchical deployment of different levels of diverse equipment and procedures to prevent theescalation of anticipated operational occurrences and to maintain the effectiveness of physical barriers
placed between a radiation source or radioactive material and workers, members of the public or theenvironment, in operational states and, for some barriers, in accident conditions.

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defined specifications (spécifications définies)
The criteria that specify the capability or performance level that a structure, system or component of a
nuclear power plant (NPP) must possess or attain so that the NPP can function effectively and reliably, in
accordance with its safety targets. These criteria are set out in an NPP’s version-controlled documents orlicensee documents requiring notification of change. Note: This definition applies specifically to NPP
reporting requirements.
degraded state (état dégradé)
The state of a structure, system or component such that it exhibits reduced performance but can still bedeclared available according to specified success criteria.
delayed hydride cracking (fissuration par hydruration retardée)
A crack initiation and growth mechanism that may occur when certain hydride-forming materials are
exposed to hydrogen and stress. For example, in CANDU pressure tubes, the zirconium alloy of thepressure tubes is a susceptible material and is exposed to hydrogen in solution.
deleterious substance (substance nocive)
Means:(a) any substance that, if added to any water, would degrade or alter or form part of a process ofdegradation or alteration of the quality of that water so that it is rendered or is likely to be rendered
deleterious to fish or fish habitat or to the use by man of fish that frequent that water, or(b) any water that contains a substance in such quantity or concentration, or that has been so treated,
processed or changed, by heat or other means, from a natural state that it would, if added to any otherwater, degrade or alter or form part of a process of degradation or alteration of the quality of thatwater so that it is rendered or is likely to be rendered deleterious to fish or fish habitat or to the use by
man of fish that frequent that water,
and without limiting the generality of the foregoing includes(c) any substance or class of substances prescribed pursuant to paragraph (2)(a),(d) any water that contains any substance or class of substances in a quantity or concentration that isequal to or in excess of a quantity or concentration prescribed in respect of that substance or class of
substances pursuant to paragraph (2)(b), and(e) any water that has been subjected to a treatment, process or changes prescribed pursuant toparagraph (2)(c).
(Source: Fisheries Act)
depleted uranium (uranium appauvri)
Uranium that contains uranium-235 in a concentration that is less than that normally found in nature.
(Source: Nuclear Substances and Radiation Devices Regulations)
Note: In the context of packaging and transport of nuclear substances, depleted uranium means uranium
containing a lesser mass percentage of uranium-235 than natural uranium.
derived activity (DA) (activité dérivée [AD])The expected retention or excretion rate, expressed as becquerels or becquerels per day, from a single
measurement of a radionuclide made at the end of a monitoring period, such that the corresponding
extrapolated annual committed effective dose is equal to 1 millisievert. The DA is calculated with theassumption that the intake occurs at the mid-point in the monitoring period.
derived air concentration (DAC) (limite dérivée de concentration dans l’air [LDCA])
The concentration of a radionuclide in air that, when inhaled at a breathing rate of 1.2 m3 per hour for
2,000 hours per year, results in the intake of 1 annual limit on intake.

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derived investigational level (DIL) (niveau d’enquête dérivé [NED])
With respect to a program that monitors internal dosimetry, the predetermined level of contamination thattriggers an investigation and dose assessment. The DIL, measured in becquerels, is commonly set byprograms for monitoring internal contamination and is one of several actions that may be taken whencontamination rises above certain levels.
derived reference level (niveau de référence dérivé)
Bioassay-determined activity due to occupational sources, measured in becquerels per litre.
derived release limit (DRL) (limite de rejet dérivée [LRD])As defined in the CSA Group publication CSA N288.1, Guidelines for calculating derived release limits
for radioactive material in airborne and liquid effluents for normal operation of nuclear facilities [3]:the release rate that would cause an individual of the most highly exposed group to receive and becommitted to a dose equal to the regulatory annual dose limit due to release of a given radionuclide to
air or surface water during normal operation of a nuclear facility over the period of a calendar year.
design (conception)
In the context of a reactor design review, the overall planning and philosophies that go into ensuring thatevery aspect of the physical design will consider safety, security and safeguards under all scenarios it may
encounter during its lifecycle. See also design basis.
designated non-nuclear response force personnel (personnel désigné qui ne fait pas partie de la forced’intervention pour la sécurité nucléaire)
Nuclear security staff who are authorized under the Public Agents Firearms Regulations to possess or
have access to prohibited and restricted firearms, items or devices on behalf of and under the authority of
the CNSC for the purpose of carrying out their duties. These duties may encompass the storage, transport,
handling, maintenance and use of firearms related to onsite nuclear response force functions. See also
onsite nuclear response force.
designated officer (DO) (fonctionnaire désigné)
A person designated as a designated officer under section 37. (Source: Nuclear Safety and Control Act)
Note: The DO is considered qualified to perform duties specified under the Nuclear Safety and Control
Act, on behalf of the Commission. The DO may be a CNSC employee or a person otherwise employed
under an arrangement with the CNSC.
designated project (projet désigné)
One or more physical activities that(a) are carried out in Canada or on federal lands;(b) are designated by regulations made under paragraph 84(a) [of the Canadian Environmental
Assessment Act, 2012 (CEAA 2012)] or designated in an order made by the Minister [of theEnvironment] under subsection 14(2) [of CEAA 2012]; and(c) are linked to the same federal authority as specified in those regulations or that order.
It includes any physical activity that is incidental to those physical activities. (Source: Canadian
Environmental Assessment Act, 2012)
design authority (autorité en matière de conception)
The entity that has overall responsibility for the design process, or the responsibility for approving designchanges and for ensuring that the requisite knowledge is maintained.

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design basis (dimensionnement)
The range of conditions and events taken explicitly into account in the design of a nuclear facility,
according to established criteria, such that the facility can withstand this range without exceeding
authorized limits. Note: Design extension conditions are not part of the design basis.
design-basis accident (DBA) (accident de dimensionnement [AD])Accident conditions for which a nuclear facility is designed according to established design criteria andfor which damage to the fuel and the release of radioactive material are kept within authorized limits.
DBA is a plant state.
design-basis earthquake (DBE) (séisme de référence [SR])As defined in the CSA Group publication CSA N289.1-08, General requirements for seismic design andqualification of CANDU nuclear power plants [4] referenced in the nuclear power plant licence:an engineering representation of potentially severe effects at the site due to earthquake ground motions
having a selected probability of exceedance of 1x10-4 per year, or such probability level as determined by
the regulatory authority.
Notes:
1) DBE ground motions are usually referred to as an “earthquake”, and can take the form of a response
spectrum, or time history of acceleration, velocity, or displacement.
2) The DBE is used for the seismic qualification of certain structures, systems, and components. It is
used as an input for nuclear power plant seismic design, analysis, and testing to produce a design that is
adequate for the specified seismic hazard.
3) The DBE for some older plants was based on an estimated probability of exceedance of 1x10-3 peryear or was established deterministically (i.e., without probabilistic measures).
design-basis threat (DBT) (menace de référence)
The characteristics of a potential adversary in respect of which countermeasures are incorporated into thedesign and evaluation of a physical protection system. (Source: Nuclear Security Regulations)design envelope (enveloppe de conception)
The range of conditions and events (including design extension conditions) that are explicitly taken into
account in the design of a nuclear facility, such that significant radioactive releases would be practicallyeliminated by the planned operation of process and control systems, safety systems, safety support
systems and complementary design features.
design extension conditions (DEC) (conditions additionnelles de dimensionnement [CAD])
A subset of beyond-design-basis accidents that are considered in the design process of the facility inaccordance with best-estimate methodology to keep releases of radioactive material within acceptable
limits. Design extension conditions could include severe accident conditions. DEC is a plant state.
desktop review (examen des documents ou examen documentaire)
See compliance assessment.
detailed decommissioning plan (plan détaillé de déclassement)
A plan setting out the detailed work program, safety and environmental protection procedures, andmanagement systems that will be followed in the decommissioning of a licensed activity/facility.
Note: Detailed decommissioning plans should evolve from the preliminary decommissioning plan.
deterministic effect (effet déterministe)
A health effect of radiation for which a threshold level of dose generally exists above which the severityof the effect is greater for a higher dose.

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deterministic safety analysis (analyse déterministe de la sûreté)
An analysis of a nuclear facility’s responses to an event, performed using predetermined rules andassumptions (such as those concerning the initial facility operational state, availability and performance ofthe facility systems and operator actions). Deterministic safety analysis can use either conservative or
best-estimate methods.
dewatering water (eau d’assèchement)
Groundwater intercepted by pumps to prevent it from flowing into open pits or into the undergroundworkings of a mine.
DGR (DGP)
See deep geological repository.
diagnostic nuclear medicine (médecine nucléaire diagnostique)
The administration of unsealed sources (nuclear substances) to humans for diagnostic purposes related totheir healthcare. Diagnostic nuclear medicine includes the processing of radiopharmaceuticals andlaboratory studies that are part of the diagnostic studies.
DIL (NED)See derived investigational level.
direct bioassay (essai biologique direct)
See bioassay.
direct effect (effet direct)
An effect in which the cause–effect relationship has no intermediary effects.
direct (in vivo) radiobioassay (essai biologique direct [mesures in vivo])
See bioassay.
direct regulatory activities (activités de réglementation directes)
Those activities, such as assessing applications, issuing licences and certificates, granting approvals andauthorizations, verifying and enforcing compliance and providing information, products and services, thatare required for the Commission to fulfill its regulatory responsibilities. (Source: Canadian Nuclear
Safety Commission Cost Recovery Fees Regulations)direct trip parameter (paramètre de déclenchement direct)
A process or neutronic parameter that is used to trigger a shutdown action and that is a direct measure of
the challenge to derived acceptance criteria or a direct measure of the event taking place.
direct visual surveillance (surveillance visuelle directe)
Direct observation by a person who is physically present at the place that is under observation.
(Source: Nuclear Security Regulations)disconnect (déconnecté)
A condition in which the sealed source assembly is inadvertently released from the control cable.
discretization (discrétisation)
A method of approximation of the true mathematical function to be integrated.

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dismantling (démantèlement)
With respect to radiation devices, means to take apart a device to repair, replace or remove faulty
components that may include the nuclear substance of that device (part of the licensed activity ofservicing, installation and dismantling of devices containing radioisotopes).
OR
With respect to decommissioning, means to take apart, disassemble and tear down the structures, systems
and components of a facility, location or site for the purposes of decommissioning.
dismounting (démontage)
See install.
disorderly crowd (foule désordonnée)
A group of people in a recognizable area, with behaviours classified as one of five types: casual, cohesive,
expressive, demonstration and aggressive. Note: Each type requires careful consideration on how tomanage it. The tactics range from simple crowd monitoring to the presence of uniformed officers
interacting with individuals in the crowd, to the deployment of an offsite public order unit. Deployment
and the tactics used are judgment calls based on the overall strategies determined by the commander tomanage crowds at all levels of order, using the least amount of force.
disposal (évacuation or élimination)
The placement of radioactive waste without the intention of retrieval.
diversity (diversité)
The presence of two or more redundant systems or components to perform an identified function, where
the different systems or components have different attributes so as to reduce the possibility of commoncause failure.
division (division)
The designation applied to a given system or set of components that enables the establishment andmaintenance of physical, electrical and functional independence from other redundant sets of components.
DO (fonctionnaire désigné)
See designated officer.
dose acceptance criteria (critères d’acceptation des doses)
With respect to safety analysis, bounds for radiation doses that are established to protect workers and the
public from the release of nuclear substances from a reactor facility during normal operation, anticipatedoperational occurrences and design-basis accidents.
dose conversion factor (DCF) (facteur de conversion de la dose [FCD])
The committed effective dose in sieverts, per unit activity in becquerels, delivered by a given radionuclideof a given form.
dose information (renseignements sur les doses)
The occupational radiation doses of monitored workers on record with the National Dose Registry(NDR). This dose information includes annual summaries, discrete dose details, cumulative dose totals,
dose histories, dose type, pregnant worker dose information, and exposure to radon progeny. Note: Doseinformation excludes other information in the worker’s NDR record, such as the worker’s name, date ofbirth, pregnancy declaration date, social insurance number, employer and job category.

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dose limit (limite de dose)
A maximum allowable radiation dose (effective dose or equivalent dose), as specified in the Radiation
Protection Regulations, which is in place to minimize the risk of adverse health effects due to radiation
exposure.
dose of record (dose enregistrée)
Data about an individual’s radiation dose that has been measured by a licensed dosimetry service andsubmitted to the National Dose Registry.
dosimeter (dosimètre)A device for measuring a dose of radiation that is worn or carried by an individual. (Sources: Nuclear
Substances and Radiation Devices Regulations; Radiation Protection Regulations)
Note: Among common types are thermoluminescent and optically stimulated luminescent dosimeters.
dosimetry period – one-year (période de dosimétrie d’un an)
See one-year dosimetry period.
dosimetry period – five-year (période de dosimétrie de cinq ans)
See five-year dosimetry period.
dosimetry service (services de dosimétrie)
A prescribed facility for the measurement and monitoring of doses of radiation. (Source: Nuclear Safety
and Control Act)
dosimetry types (types de dosimétrie)
The methods used for measuring radiation dose in or excreted from a body or in radioactive atmospheres.
• External dosimetry is usually employed for photon (that is, X and gamma) radiation, but may also
be used for beta and neutron radiation sources outside of the body.
• Internal dosimetry involves bioassay in the form of either in vitro monitoring, in vivo monitoring, ora combination of the two.
• Radioactive atmosphere is usually measured by air monitoring techniques. Typical measurements
are for radon progeny and radioactive dusts in uranium mines.
double contingency principle (principe de contingence double)
A characteristic or attribute of a process that has incorporated sufficient safety factors so that at least two
unlikely, independent and concurrent changes in process conditions are required before a nuclear
criticality accident is possible.
drill (exercice de simulation)
See emergency drill.
drive cable (câble de commande)See control cable.
drive mechanism (mécanisme de commande)See remote control.
DRL (LRD)
See derived release limit.

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dry mouth (bouche sèche)The inability of a donor to provide a sufficient amount or volume of oral fluid (that is, saliva) to permit avalid oral fluid drug test.
DSP (MSD)
designated supervising physician
dual-use item (article à double usage)
See nuclear and nuclear-related dual-use items.
duty area (fonction)
One of a job incumbent’s main areas of activity or a grouping of closely related tasks.

E
E (E)
See effective dose.
EA (EE)See environmental assessment.
EA report (rapport d’EE)
See environmental assessment (EA) report under the NSCA or environmental assessment (EA) reportunder CEAA 2012.
ECCS (SRUC)
See emergency core cooling system.
effective dose (E) (dose efficace[E])The sum of the products, in sievert, obtained by multiplying the equivalent dose of radiation received byand committed to each organ or tissue set out in column 1 of an item of Schedule 1 by the weighting
factor set out in column 2 of that item. (Source: Radiation Protection Regulations)
Note 1: Effective dose is a measure of the total detriment, or risk, due to an exposure to ionizing
radiation. If the exposure to different organs or tissues is not uniform (as is the case when radionuclides
are deposited in the body), the concept of effective dose is used. The basic idea is to express the risk fromthe exposure to a single organ or tissue in terms of the equivalent risk from an exposure to the wholebody. The unit of effective dose is the sievert.
Note 2: Equivalent dose and effective dose are protection quantities used to reflect how radiation
exposure can affect overall health of the human body. They specify dose values, which are derived fromthe body’s absorbed dose, for limiting the occurrence of stochastic health effects below acceptable levels
and avoiding tissue reactions. The effective dose is designed to reflect these differences and how exposure
can affect overall health of the whole body.
Note 3: The term weighting factor refers to the tissue weighting factor, which takes into account thatdifferent organs and tissue have different radiation sensitivities. For example, bone marrow is much moreradiosensitive than muscle or nerve tissue. Effective dose is the summation of the tissue equivalent doses,
each multiplied by the appropriate tissue weighting factor. It is defined by:

E =  w T  w R DT , R
TR

where wT is the tissue weighting factor with ∑wT = 1. The sum is performed over all organs and tissues
considered in the definition of E.

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Note 4: Use of absorbed dose alone is not valid for estimating risk, as radiation effects depend not only
on the absorbed dose but also on a) the type of radiation, b) the distribution of energy absorption in timeand space within the human body and c) the radiosensitivity of the exposed tissues or organs.
See also absorbed dose, equivalent dose.
effective full power hour (EFPH) (heure équivalente pleine puissance HEPP])
See equivalent full power hour (EFPH).
effective half-life (demi-vie effective)
The time required for a radionuclide deposited in the body to decrease to one-half of its initial quantity asa result of the combined action of radioactive decay and biological elimination.
effective intervention (défense efficace)
An intervention that is timely and powerful enough to prevent a person or a group of persons, including
those equipped with weapons or explosive substances, from committing sabotage or from removing
Category I, II or III nuclear material otherwise than in accordance with a licence. (Source: Nuclear
Security Regulations)effective kilogram (Ekg) (kilogramme effectif [kgE])
A unit of measurement used in accounting and reporting of safeguarded nuclear material. The quantity ineffective kilograms is obtained by taking:• for plutonium, its weight in kilograms• for uranium with an enrichment of 0.01 (1%) and above, its weight in kilograms multiplied by thesquare of its enrichment• for uranium with an enrichment below 0.01 (1%) and above 0.005 (0.5%), its weight in kilograms
multiplied by 0.0001• for depleted uranium with an enrichment of 0.005 (0.5%) or below, and for thorium, its weight inkilograms multiplied by 0.00005
effective multiplication factor (keff) (facteur de multiplication effectif [keff])• Physically, the ratio of the total number of neutrons produced during a time interval (excluding
neutrons produced by sources whose strengths are not a function of fission rate) to the total number ofneutrons lost by absorption and leakage during the same interval.
• Mathematically (computationally), the eigenvalue number that, when divided into the actual mean
number of neutrons emitted per fission in an assembly of materials, would make the calculated result
for the nuclear chain reaction of that assembly critical.
Also called effective neutron multiplication factor.
effluent (effluent)A waterborne release of a hazardous or nuclear substance to the environment.
Note: This definition differs from that in CSA N288.6, Environmental risk assessments at Class I nuclear
facilities and uranium mines and mills [5], which defines effluent as “the release of contaminants into theenvironment (including both air and water) as a result of a licensed activity during normal operations”.
See also emission.
EFPD (JEPP)
equivalent full-power day
EFPH (HEPP)
See equivalent full power hour.

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REGDOC-3.6, Glossary of CNSC Terminology

EHRS (SEUC)
emergency heat removal system
EIR (RIE)
event initial report
EIS (EIE)
See environmental impact statement.
Ekg (kgE)
See effective kilogram.

ELAP (PPACA)
extended loss of AC powerelectrical interaction (interaction électrique)
A force of repulsion acting between electric charges of like sign (charge), or a force of attraction acting
between electric charges of unlike sign (charge).
electron volt (eV) (électronvolt [eV])A unit of energy employed in radiation physics. An eV is equal to the energy that an electron gains when
it passes through a potential difference of 1 volt. 1 eV = 1.6 x 10-19 joules.
EME (EAU)
emergency mitigating equipment
emergency coordinator (coordonnateur des mesures d’urgence)
A person authorized to direct an overall emergency response.
emergency core cooling system (ECCS) (système de refroidissement d’urgence du cœur [SRUC])
A safety system that transfers heat from a reactor core, following a loss of reactor coolant or certain otheraccidents that exceed makeup capability.
emergency drill (manœuvre d’urgence)Supervised instruction intended to test, develop, maintain and practise the skills required in a particularemergency response activity.
emergency exercise (exercice d’urgence)
Simulation of emergency events to test the integrated performance of an emergency response scenario.
With respect to nuclear criticality safety, this term means an activity that tests one or more portions of theintegrated capability of emergency response plans, equipment and organizations.
emergency management and fire protection SCA (DSR Gestion des urgences et protection-incendie)
A safety and control area (SCA) that covers emergency plans and emergency preparedness programs thatexist for emergencies and for non-routine conditions. This area also includes any results of participationin exercises. This SCA is one of the 14 within the CNSC SCA Framework.
emergency operating procedures (procédures d'exploitation sur incident)
Reactor specific procedures containing instructions to operating staff for implementing measures toterminate some anticipated operational occurrences and to prevent core degradation in design-basis
accidents and/or beyond-design-basis accidents.

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REGDOC-3.6, Glossary of CNSC Terminology

emergency plan (plan d’urgence)
The documented measures required of applicants and licensees under the Class I Nuclear Facilities
Regulations and Uranium Mines and Mills Regulations. Accordingly, an emergency plan for a Class I
nuclear facility or a uranium mine or mill consists of a proposed or actual program to cope with accidental
releases. This program encompasses both emergency preparedness and emergency response measures.
emergency response (intervention d’urgence)
The integrated set of equipment, procedures and personnel necessary for performing a specified function
or task required for preventing, mitigating or controlling the effects of an accidental release.
OR
With respect to nuclear criticality safety, actions taken from the time of identification of a suspected,
imminent or actual criticality accident until stabilization of the event. These actions include theassumption that an accident has occurred, there has been a response to the emergency, and actions tobegin subsequent recovery operations have taken place.
emergency response facility (installation d’intervention d’urgence)
An area or room that can be immediately activated when required during an emergency/incident.
emergency response organization (ERO) (organisation d’intervention d’urgence [OIU])
A group of interrelated responders with predefined roles and responsibilities, who work together tomitigate the consequences of an emergency.
emergency response procedures (procédures d'intervention en cas d'urgence)
A set of instructions with a detailed description of the actions to be taken by response personnel during an
emergency.
emission (émission)
An airborne release of a hazardous or nuclear substance to the environment. An emission may include
point sources, fugitive emissions or area sources. See also effluent.
EMS (SGE)
See environmental management system.
enabling objective (EO) (objectif de base)A principal learning unit that constitutes a major step towards achieving one or more associated terminal
learning objectives. The EO consists of a performance statement, condition statement and a standard.
encapsulated source (source encapsulée)Radioactive material that is permanently sealed in a capsule or closely bounded in a solid form.
end state (état final)With respect to decommissioning, the proposed physical, chemical and radiological condition of a facility
at the end of the decommissioning program. Note: Where a decommissioning program is to take place indiscrete phases, the interim end-state objectives for each phase should be defined.
end-use controls (contrôles de l’utilisation ultime)
Controls over items that are not otherwise listed in the Nuclear Non-proliferation Import and Export
Control Regulations, when such items may be intended for use in connection with a nuclear weapons
program or nuclear explosive device. Also called catch-all controls.

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REGDOC-3.6, Glossary of CNSC Terminology

enforcement (application de la loi)
All activities to compel a licensee back into compliance and to deter further non-compliances with the
Nuclear Safety and Control Act (NSCA), the regulations made under the NSCA, and licences, decisions,certificates and orders made by the CNSC.
engineered (nuclear) criticality safety control (contrôle technique de sûreté-criticité [nucléaire])
Either an active or passive engineered control:• active engineered control: a physical device that uses active sensors, electrical components ormoving parts to maintain safe process conditions without any required human action• passive engineered control: a device that uses only fixed physical design features to maintain safe
process conditions without any required human action
enhanced administrative control (contrôle administratif amélioré)
See administrative (nuclear) criticality safety control.
enriched uranium (uranium enrichi)
Uranium having a higher abundance of the fissile isotopes (uranium-235, uranium-233 or a combinationof both) than natural uranium. Note: In the context of packaging and transport of nuclear substances,enriched uranium means uranium containing a greater mass percentage of uranium-235 than 0.72 percent.
A very small mass percentage of uranium-234 is present.
environment (environnement)
The components of the Earth:• land, water and air, including all layers of the atmosphere• all organic and inorganic matter and living organisms• the interacting natural systems that include the above components
environmental assessment (EA) report for an EA under CEAA 2012 (rapport d’évaluation
environnementale [EE] pour une EE en vertu de la LCEE 2012)
A document summarizing the EA process [under the Canadian Environmental Assessment Act, 2012] thattakes into consideration the analysis by the proponent and associated perspectives of expert federal
authorities, the public, Aboriginal groups, the province (as appropriate) and the responsible authority.
(Source: Practitioners Glossary for the Environmental Assessment of Designated Projects under the
Canadian Environmental Assessment Act, 2012 [1]) See also environmental assessment (EA) report for
an EA under the NSCA.
environmental assessment (EA) report for an EA under the NSCA (rapport d’évaluation
environnementale [EE] pour une EE en vertu de la LSRN)
A report prepared by CNSC staff, for the Commission or a designated officer, which documents thefindings of an EA under the Nuclear Safety and Control Act (NSCA). Note: On a case-by-case basis,
CNSC staff determine the content and appropriate level of detail of this type of report, based on andcommensurate with the scale and complexity of the facility or activity and taking into consideration
Indigenous, public and regulatory interest. This type of EA report describes and summarizes the results ofenvironmental monitoring, effluent and emissions monitoring and the risks to the environment and the
public. Where available, environmental compliance monitoring data and the results of any sampling andanalysis activities of the Independent Environmental Monitoring Program (IEMP) conducted nearfacilities are also included. In particular, the EA report for an EA under the NSCA covers those elementsof the facility or activity that are deemed to be of Indigenous, public or general interest. See also
environmental assessment (EA) report for an EA under CEAA 2012.

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environmental assessment (EA) under CEAA 2012 (évaluation environnementale [EE] en vertu de la
LCEE 2012)
An assessment of the environmental effects of a designated project that is conducted in accordance with[the Canadian Environmental Assessment Act, 2012]. (Source: Canadian Environmental Assessment
Act, 2012))
Note: As further described in the Practitioners Glossary for the Environmental Assessment of DesignatedProjects Under the Canadian Environmental Assessment Act, 2012 [1], “An [environmental assessment(EA) under CEAA 2012] predicts the environmental effects of a designated project, identifies mitigation
measures, assesses whether the designated project is likely to cause significant adverse environmental
effects taking into account identified mitigation measures, and ensures a follow-up program is designatedto verify the accuracy of the EA of the designated project and effectiveness of any mitigation measures.”
Compare to environmental protection review (EPR) under the NSCA.
environmental assessment (EA) under the NSCA (évaluation environnementale [EE] en vertu de la
LSRN)
See environmental protection review (EPR) under the NSCA. Compare to environmental assessment(EA) under CEAA 2012.
environmental control (contrôle environnemental)
Environmental management procedures or engineering technology and/or techniques that prevent or
minimize the release of nuclear and hazardous substances to the environment.
environmental effects (effets environnementaux)
Any change to the environment, whether adverse or beneficial, wholly or partly resulting from a licensed
activity or facility, including:(a) any change that an activity, substance, equipment, facility or prescribed information may cause in theenvironment, including any change it may cause to a listed wildlife species, its critical habitat or the
residences of individuals of that species, as those terms are defined in subsection 2(1) of the Species at
Risk Act(b) any effect of any change referred to in (a) on:• health and socio-economic conditions• physical and cultural heritage• the current use of lands and resources for traditional purposes by Indigenous peoples• any structure, site or thing that is of historical, archaeological, paleontological or architectural
significancewhether any such change or effect occurs within or outside Canada
ORWith respect to an environmental assessment under the Canadian Environmental Assessment Act, 2012
(CEAA 2012), the environmental effects described in section 5 [of that Act]. (Source: Canadian
Environmental Assessment Act, 2012))
Note: Section 5 of CEAA 2012 describes environmental effects as follows:(1) For the purposes of this Act, the environmental effects that are to be taken into account in relation toan act or thing, a physical activity, a designated project or a project are(a) a change that may be caused to the following components of the environment that are within thelegislative authority of Parliament:(i) fish and fish habitat as defined in subsection 2(1) of the Fisheries Act,(ii) aquatic species as defined in subsection 2(1) of the Species at Risk Act,(iii) migratory birds as defined in subsection 2(1) of the Migratory Birds Convention Act, 1994,
and(iv) any other component of the environment that is set out in Schedule 2;45

February 2023

REGDOC-3.6, Glossary of CNSC Terminology(b) a change that may be caused to the environment that would occur(i) on federal lands,(ii) in a province other than the one in which the act or thing is done or where the physicalactivity, the designated project or the project is being carried out, or(iii) outside Canada; and(c) with respect to aboriginal peoples, an effect occurring in Canada of any change that may becaused to the environment on(i) health and socio-economic conditions,(ii) physical and cultural heritage,(iii) the current use of lands and resources for traditional purposes, or(iv) any structure, site or thing that is of historical, archaeological, paleontological or architectural
significance.
(2) However, if the carrying out of the physical activity, the designated project or the project requires afederal authority to exercise a power or perform a duty or function conferred on it under any Act ofParliament other than this Act, the following environmental effects are also to be taken into account:(a) a change, other than those referred to in paragraphs (1)(a) and (b), that may be caused to theenvironment and that is directly linked or necessarily incidental to a federal authority’s exercise of apower or performance of a duty or function that would permit the carrying out, in whole or in part, ofthe physical activity, the designated project or the project; and(b) an effect, other than those referred to in paragraph (1)(c), of any change referred to inparagraph (a) on(i) health and socio-economic conditions,(ii) physical and cultural heritage, or(iii) any structure, site or thing that is of historical, archaeological, paleontological or architectural
significance.
(3) The Governor in Council may, by order, amend Schedule 2 to add or remove a component of theenvironment.
environmental impact statement (EIS) (étude d’impact environnemental (EIE)
A detailed technical document prepared by the proponent of a designated project to be assessed pursuant
to [the Canadian Environmental Assessment Act, 2012]. The environmental impact statement identifies
the potential adverse environmental effects of a designated project including cumulative effects, measures
to mitigate those effects, and an evaluation of whether the designated project is likely to cause any
significant adverse environmental effects. (Source: Practitioners Glossary for the Environmental
Assessment of Designated Projects Under the Canadian Environmental Assessment Act, 2012 [1])environmental management system (EMS) (système de gestion de l’environnement [SGE])
The part of an organization’s management system used to develop and implement its environmental
policy and manage its environmental aspects. An EMS consists of policies and procedures forming an
integrated set of documented activities to provide a framework for effective environmental protection
measures.

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environmental protection review (EPR) under the NSCA (examen de la protection de l’environnement[EPE] en vertu de la LSRN)
A science-based environmental technical assessment by CNSC staff as set out in the Nuclear Safety andControl Act (NSCA) for all licence applications with potential environmental interactions in accordancewith the CNSC’s mandate under the NSCA to ensure the protection of the environment and the health of
persons.
Note: Where there are potential environmental interactions, an EPR under the NSCA is conducted for
projects not subject to the Impact Assessment Act or other applicable environmental assessment
legislation. An EPR describes the outcome of CNSC staff’s review of licensing and environmental
compliance activities conducted under the NSCA. This review serves to assess whether the applicant or
licensee will, in carrying on a licensed activity, make adequate provision for the protection of theenvironment and health of persons. This assessment is commensurate with the scale and complexity of theenvironmental risks associated with the nuclear facility or activity.
environmental protection SCA (DSR Protection de l’environnement)
A safety and control area (SCA) that covers programs that identify, control and monitor all releases ofradioactive and hazardous substances and effects on the environment from facilities or as the result oflicensed activities. This SCA is one of the 14 within the CNSC SCA Framework.
environmental review (évaluation environnementale)See environmental assessment (EA) under CEAA 2012 or environmental protection review (EPR) under
the NSCA.
environmental risk assessment (ERA) (évaluation des risques environnementaux [ERE])
A process that identifies, quantifies and characterizes the risk posed by contaminants (nuclear or
hazardous substances) and physical stressors in the environment. An ERA is a practice or methodology
primarily developed by regulatory agencies to provide scientific input to decision makers. In this way,
ERAs commonly serve as a supportive tool providing technical information in a manageable form to alarger EA.
EO
See enabling objective.
EPREV (EPREV)
Emergency Preparedness Review (an IAEA service
EPS (AEU)
emergency power supply

EQ (QE)
environmental qualificationequipment qualification (qualification de l’équipement)
The process for certifying equipment as having satisfied the requirements for operability under conditions
relevant to its safety functions. Equipment qualification includes the generation and maintenance ofevidence to ensure that equipment will operate on demand, under specified service conditions, to meetsystem performance requirements.

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REGDOC-3.6, Glossary of CNSC Terminology

equivalent dose (HT) (dose équivalente [HT])The product, in sievert, obtained by multiplying the absorbed dose of radiation of the type set out incolumn 1 of an item of Schedule 2 by the weighting factor set out in column 2 of that item.
(Sources: Radiation Protection Regulations; Packaging and Transport of Nuclear Substances
Regulations, 2015)
Note 1: Equivalent dose and effective dose are protection quantities used to reflect how radiation
exposure can affect overall health of the human body. They specify dose values, which are derived fromthe body’s absorbed dose, for limiting the occurrence of stochastic health effects below acceptable levels
and avoiding tissue reactions. The equivalent dose (multiplying the radiation type by its radiation
weighting factor) is designed to reflect the amount of harm caused, regardless of the type of radiation.
Values (expressed in seiverts) of equivalent dose to a specified tissue or organ from any type(s) ofradiation can be compared directly.
Note 2: The term weighting factor refers to the radiation weighting factor. The equivalent dose is theradiation-weighted dose in an organ or tissue. This value is based on the mean absorbed dose, DT,R, due toradiation of type R and averaged over the volume of a specific organ or tissue T and is defined by:

H T =  wR DT , R
R

Note 3: Use of absorbed dose alone is not valid for estimating risk, as radiation effects depend not only
on the absorbed dose but also on a) the type of radiation, b) the distribution of energy absorption in timeand space within the human body and c) the radiosensitivity of the exposed tissues or organs.
See also absorbed dose, effective dose.
equivalent full power hour (EFPH) (heure équivalente pleine puissance [HEPP])
The period over which a component sees service that equals the amount of full service the component
would have experienced if it had been operated continuously over a full hour.
ERA (ERE)
See environmental risk assessment.
ERO (OIU)
See emergency response organization.
ESC (CSU)
emergency support centre
escort (escorte)
An individual (normally a staff member or a nuclear security officer) who is authorized by theCommission and licensee to enter the protected or inner area of a nuclear facility and who has been
assigned to accompany persons granted escorted entry to the area by the licensee. The escort is expected
to maintain control over the activity of the person(s) under escort at all times.
OR
Any person who accompanies a consignment of nuclear material to provide protection against
compromise or attack.
ESWS (SSUAE)
emergency secondary water supply systemeV (eV)See electron volt.

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evaluator (évaluateur)
In an emergency drill or exercise, a qualified person who observes, evaluates and critiques the emergency
responders’ actions based on pre-established performance criteria.
event (événement)
Any unintended occurrence, including operating error, equipment failure or another mishap, or deliberateaction on the part of others, the consequences or potential consequences of which may be significant fromthe point of view of protection or safety.
event category (catégorie d’événement)
A group of events characterized by the same or similar cause and similarity in the governing phenomena.
event review (examen d’événement)
All verification activities related to reviewing, assessing and trending of event reports.
excavation site (site d’excavation)
A place at which uranium is moved by means of underground activities for the purpose of evaluating a
potential ore body. (Source: Uranium Mines and Mills Regulations)
excepted package (colis excepté)
A package that is designed in accordance with the applicable requirements of the IAEA Regulations.
(Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
excessive radiation dose (dose de rayonnement excessive)
In a nuclear criticality accident, any dose to personnel corresponding to an absorbed dose from neutrons
and gamma rays equal to or greater than 0.12 gray in free air.
excited state (état excité)
A state of energy of an electron or nucleus when its energy level is higher than in the ground state.
exclusion zone (zone d’exclusion)
A parcel of land within or surrounding a nuclear facility on which there is no permanent dwelling andover which a licensee has the legal authority to exercise control. (Source: Class I Nuclear Facilities
Regulations)exclusive use (utilisation exclusive)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
excretion function (m) (fonction d’excrétion [m])A mathematical expression for the fractional excretion of a radionuclide from the body at any time
following intake, generally expressed as becquerels excreted per day, per becquerel taken in.
exempted material (matière exemptée)With respect to nuclear material accounting, any nuclear material that was initially classified as Group 1A
and has been granted a temporary classification to Group 1B. The material remains classified asGroup 1B until it is reclassified to Group 1A. Material may be exempted on the basis of non-nuclear use
or by a quantity less than 1 effective kilogram.

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REGDOC-3.6, Glossary of CNSC Terminology

exemption quantity (quantité d’exemption)
Any of the following:(a) in respect of a radioactive nuclear substance set out in column 1 of Schedule 1,(i) if the radioactive nuclear substance is uniformly distributed in material and not in bulk quantity,
the corresponding activity concentration set out in column 2, or(ii) the corresponding activity set out in column 3;(b) in respect of a radioactive nuclear substance that is not set out in column 1 of Schedule 1,(i) if the atomic number of the substance is equal to or less than 81,(A) 10 Bq/g if the radioactive nuclear substance is uniformly distributed in material and not inbulk quantity, or(B) 10,000 Bq,(ii) if the atomic number of the substance is greater than 81 and the substance, or its short-lived
radioactive progeny, does not emit alpha radiation,(A) 10 Bq/g if the radioactive nuclear substance is uniformly distributed in material and not inbulk quantity, or(B) 10,000 Bq, or(iii) if the atomic number of the substance is greater than 81 and the substance, or its short-lived
radioactive progeny, emits alpha radiation,(A) 1 Bq/g if the radioactive nuclear substance is uniformly distributed in material and not inbulk quantity, or(B) 1,000 Bq; or(c) in respect of more than one radioactive nuclear substance,(i) if the radioactive nuclear substances are uniformly distributed in material and not in bulk
quantity, the quotient obtained by dividing the total activity concentration by the sum of
quotients obtained by dividing the activity concentration of each radioactive nuclear substanceby its corresponding exemption quantity as referred to in paragraph (a) or (b), or(ii) the quotient obtained by dividing the total activity by the corresponding sum of quotientsobtained by dividing the activity of each radioactive nuclear substance by its corresponding
exemption quantity as referred to in paragraph (a) or (b).
(Source: Nuclear Substances and Radiation Devices Regulations)
Note: Bq/g means becquerels/gram.
exempt material (matière exemptée)With respect to the packaging and transport of a nuclear substance, a nuclear substance having an activity
concentration that does not exceed the values for an exempt material specified in paragraphs 401 to 406
of the IAEA Regulations.
exercise (exercice)See emergency exercise.
explosive substance (substance explosive)
Includes:(a) anything intended to be used to make a substance capable of producing an explosion, a detonation ora pyrotechnic effect;(b) anything, or any part of any thing, used or intended to be used or adapted to cause, or to aid incausing, an explosion in or with a substance referred to in paragraph (a); and(c) an incendiary grenade, firebomb, Molotov cocktail or other similar incendiary substance or device
and a delaying mechanism or other thing intended for use in connection with such a substance or
device.
(Source: Nuclear Security Regulations)50February 2023

REGDOC-3.6, Glossary of CNSC Terminology

export (exportation)
The transfer of a nuclear substance, prescribed equipment or prescribed information from Canada to aforeign destination.
exposure (exposition)
See irradiation.
exposure container (radiography camera) (projecteur [caméra de gammagraphie])
A shield, in the form of a container, designed to allow the controlled use of gamma radiation andemploying a sealed source assembly.
exposure device (appareil d’exposition)
A radiation device that is designed for carrying out gamma radiography, and includes any accessory to thedevice such as a sealed source assembly, a drive mechanism, a sealed source assembly guide tube and an
exposure head. (Sources: Nuclear Substances and Radiation Devices Regulations; Packaging andTransport of Nuclear Substances Regulations, 2015)
exposure device source path (organe de transmission de la source de l’appareil d’exposition)
A hollow tunnel inside an exposure container where the sealed source resides when not in use. Also called
S-tube.
exposure head (tête d’exposition)
A device that locates the sealed source included in the sealed source assembly, in the selected working
position, and prevents the sealed source assembly from projecting out of the projection sheath. A beam
limiter may also serve as an exposure head. Also called source stop.
exposure hours (heures d’exposition)
The total number of hours of employment of all employees for each member utility for each reporting
period. Note: Employees include regular hires and direct contractors / augmented / supplemented staff.
Contractors working through a separate company are not counted.
extended loss of AC power event (perte prolongée d’alimentation en CA)
See station blackout.
extended shutdown (arrêt prolongé)
A reactor shutdown lasting for a period exceeding one year and excludes regular maintenance outages.
external dosimetry (dosimétrie externe)
See dosimetry types.
external event (événement externe)
An event, unconnected with the operation of a facility or conduct of an activity, that could have an effecton the safety of the facility or activity. Some examples are earthquakes, floods, hurricanes, explosions andairplane crashes.
external hazard (danger externe)
An event of natural or human-induced origin that originates outside a site and whose effects on thefacility are considered as potentially hazardous.

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external worker (travailleur externe)
A person, employed by a firm or organization other than the licensee, who performs work that is referred
to in a licence.
extremities (extrémités)Each part of the human body that is furthest from the head and torso, and that shares similar sensitivities
to ionizing radiation. The extremities are further defined as each part of the anatomy from and including
the elbows to the tips of the fingers (the upper extremities) and from and including the knees to the tips ofthe toes (the lower extremities).

F
facility (installation)
See nuclear facility.
OR
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 “corecontrol 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 thedesign requirements or design basis, or that pertains to other information attributes associated with thefacility and its structures, systems and components.
FAI (MPF)
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 successcriterion.
failure diagnosis (diagnostic de défaillance)
A structured process for determining the cause(s) of failure of a structure, system or component.

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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 becharged 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.
OR
With respect to nuclear facilities, a synonym for failure. See failure.
federal authority (autorité fédérale)(a) a Minister of the Crown in right of Canada;(b) an agency of the Government of Canada or a parent Crown corporation, as defined insubsection 83(1) of the Financial Administration Act, or any other body established under an Act ofParliament that is ultimately accountable through a Minister of the Crown in right of Canada to
Parliament for the conduct of its affairs;(c) any department or departmental corporation that is set out in Schedule I or II to the Financial
Administration Act;(d) any other body that is set out in Schedule 1 to the Canadian Environmental Assessment Act, 2012;and(e) 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 thatis a wholly-owned subsidiary, as defined in subsection 83(1) of the Financial Administration Act, aharbour commission established under the Harbour Commissions Act or a not-for-profit corporation thatenters 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 tocirculate 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 eachanniversary date of the licence. (Source: Canadian Nuclear Safety Commission Cost Recovery Fees
Regulations)
FERP (PFIU)
Federal Emergency Response Plan

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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 tofissionable 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 adecommissioning program.
FINAS (FINAS)
fuel incident notification and analysis systemfinding (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)
See Aboriginal 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(a) excepted from being classified as fissile in accordance with the IAEA Regulations; or(b) 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.

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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.
OR
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.
OR
With respect to nuclear criticality safety, a material, other than natural uranium, that is capable ofsustaining 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. ThisSCA 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 theseRegulations 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 byfissionable material.

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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).
FLORC (PRCR)
See fast loss of reactivity control.
FNEP (PFUN)
Federal Nuclear Emergency Planfollow-up testing (test de dépistage de suivi)
Testing that is part of a follow-up plan to verify an individual’s continued abstinence from substanceabuse.
for cause (pour un motif valable)
A threshold for action (interview, further checks, denial, revocation, suspension).
OR
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.
OR
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 orthat 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 todeceive. 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 tomanufacture a specified quantity of an item but that produce a larger quantity than authorized, which isthen sold as legitimate inventory.
free neutron (neutron libre)
See neutron radiation.

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freight container (conteneur)Has the same meaning as in the International Maritime Dangerous Goods Code. (Source: Packaging andTransport of Nuclear Substances Regulations, 2015)
frequented by fish (eaux où vivent des poissons)See water frequented by fish.
FS (ES)
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 bymetallic 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 fuelrods, 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
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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 thecontrol 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 tofunction within acceptance criteria.
Fussell-Vesely (FV) importance (mesure d’importance de Fussell-Vesely [FV])
See importance measures.
FV (FV)
Fussell-Vesely. See importance measures.
FY (exerice)
See fiscal year.

G
GAI (DG)
See generic action item.
gamma radiation (rayonnement gamma)
Penetrating electromagnetic radiation emitted from an atom’s nucleus. Also called gamma rays.
gamma radiography (gammagraphie)
See industrial radiography.
gamma rays (rayons gamma)
See gamma radiation.
GAR (REG)
global assessment report; see global assessment
GBq (GBq)
gigabecquerel, that is, 109 becquerels; see becquerel.
general public (population en général)Any person who is not designated as a nuclear energy worker.

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generic action item (GAI) (dossier générique [DG])A mechanism to track safety issues, where the issues are generic to the class of facilities and have been
singled out by the Commission as requiring corrective action by the licensee within a reasonable timeframe.
geophysical well logging (diagraphie géophysique des puits de pétrole)
A neutron generator used in a borehole to measure the various geophysical properties of subsurface rockformations.
gigabecquerel (gigabecquerel)
109 becquerels; see becquerel.
glass volume fraction (fraction du volume de verre)With respect to nuclear criticality safety, the fraction of the interior volume of a Raschig ring-filled vesselthat is occupied by the glass in the rings.
global assessment (évaluation globale)
An overall risk judgment on the acceptability of continued operation of a nuclear facility.
graded approach (méthode graduelle)
A method or process by which elements such as the level of analysis, the depth of documentation and thescope of actions necessary to comply with requirements are commensurate with:• the relative risks to health, safety, security, the environment and the implementation of international
obligations to which Canada has agreed• the particular characteristics of a nuclear facility or licensed activity
graduated use of force (recours progressif à la force)
The application of approved response force options following the RCMP incident
management/intervention model or approved equivalent provincial police model.
gray (Gy) (gray [Gy])The International System of Units (SI) unit of measurement used to express absorbed dose. One gray isdefined as the absorption of 1 joule of ionizing radiation by 1 kilogram of matter. For gamma and beta
radiations, the gray is numerically equal to the sievert.
ground state (état fondamental)
The lowest-energy and most-stable state of an electron.
Group 1 nuclear material (matières nucléaires du Groupe 1)
See safeguarded nuclear material.
GSS (EAG)
See guaranteed shutdown state.
guaranteed shutdown state (GSS) (état d’arrêt garanti [EAG])A reactor state with sufficient negative reactivity to ensure subcriticality in the event of any process
failure and for which administrative safeguards (that is, reactor shutdown guarantees), approved by thesenior operations authority and with which the CNSC concurs, are in place to prevent net removal of
negative reactivity. See also safe shutdown state, shutdown state.

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guide tube (tube de guidage)
See projection sheath.
guide tube connector (raccord du tube de guidage)
See projection sheath connector.
GWD (GWj)
gigawatt-days
Gy (Gy)See gray.

H
HAC (conditions d’accident hypothétique)hypothetical accident conditions
half-life (période radioactive)
For a radionuclide, the time required for the activity to decrease, by a radioactive decay process, by half.
Note: Half-lives vary from a fraction of a second to billions of years. For example, the half-lives ofcobalt-60 and of iridium-192 are 5.3 years and 74.2 days, respectively.
half-value layer (HVL) (couche de demi-atténuation [CDA])
The thickness of a shield or absorber (such as uranium, tungsten or lead) that reduces the amount ofradiation to one half of its initial intensity. Also called half-value thickness.
half-value thickness (HVT) (épaisseur de demi-atténuation)
See half-value layer.
handheld tool (outils portatifs)
A portable tool. Some handheld tools, in the context of nuclear security, may be used by an adversary topenetrate a security system or barrier. Some examples of handheld tools are bolt cutters, pliers or hacksaw
blades, power tools, burn bars and cutting torches.
hazard analysis (analyse des dangers)
The process used to systematically identify and assess hazards to evaluate the potential internal, external,
human-made and natural events that can cause the identified hazards to initiate faults that develop into
accidents.
hazardous substance (substance dangereuse)
A substance, other than a nuclear substance, that is used or produced in the course of carrying on alicensed activity and that may pose a risk to the environment or the health and safety of persons.
(Sources: Class II Nuclear Facilities and Prescribed Equipment Regulations; Uranium Mines and Mills
Regulations)hazardous substance or hazardous waste (substance dangereuse ou déchet dangereux)
A substance or waste, other than a nuclear substance, that is used or produced in the course of carrying on
a licensed activity and that may pose a risk to the environment or the health and safety of persons.
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HCLPF (faible probabilité de défaillance avec niveau de confiance élevé [HCLPF])
high confidence of low probability of failure
HDR (HDD)
See high dose rate (HDR) brachytherapy remote afterloader.
head leakage (fuite de la tête de source)
All radiation coming from within teletherapy source housing or accelerator target housing, other than the
primary beam.
heat sink (source froide)
A system or component that provides a path for heat transfer from a source, such as heat generated in thefuel, to a large heat-absorbing medium, such as water. See also ultimate heat sink.
heat transport system (HTS) (circuit caloporteur)See primary heat transport system.
heatup rate (taux de chauffe)
The rate at which the temperature of an object increases when heated.
HEU (UHE)
See high-enriched uranium.
HEUNL (NULHE)
See highly enriched uranyl nitrate liquid.
HF (FH)See human factors.
HFE (IFH)
human factors engineering; see human factors in design
high dose rate (HDR) brachytherapy remote afterloader (appareil de curiethérapie à projecteur desource télécommandé à débit de dose élevé)A brachytherapy machine that uses a sealed source activity that, if exposed, will produce a dose rate in airof 10 milligrays per hour or greater at a distance of 1 metre from the source(s).
high energy reactor facilities
See high-power reactor facilities.
high-enriched uranium (HEU) (uranium hautement enrichi [UHE])Uranium containing 20 percent or more by weight of isotope uranium-235, isotope uranium-233, or
combined uranium-233 and uranium-235. Also called highly enriched uranium.
highly enriched uranyl nitrate liquid (HEUNL) (nitrate d’uranyle liquide hautement enrichi[NULHE])
Liquid containing high-enriched uranium.
high-power reactor facilities (installations dotées de réacteurs de haute puissance)
Power production and research reactors greater than 10 MWt.

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high-security site (site à sécurité élevée)
A nuclear power plant or a nuclear facility where Category I or II nuclear material is processed, used orstored. (Source: Nuclear Security Regulations)hold point (point d’arrêt)A commissioning activity that requires approval of the designated authority in order for commissioning toproceed.
holding account (compte de dépôt)A holding area at an identified foreign facility to which unallocated Canadian-origin nuclear material canbe exported and temporarily held pending the conclusion of a commercial arrangement for nuclear
material held in the account.
HOP (RHO)
human and organizational performance
house load operation (fonctionnement en îlotage)
Operation of a nuclear facility that is isolated from the grid and is supplying power only to its own
auxiliary electric loads. Also called island load; island operation.
HT (HT)See equivalent dose.
HTO (HTO)
hydrogenated tritium oxide; also called tritiated water
HTS
See primary heat transport system.
human error (erreur humaine)
Inappropriate or inadequate human action, including failure to take action when required, which can arise
from problems in sequencing, timing, knowledge, interfaces, procedures and other sources.
human factors (HF) (facteurs humains [FH])
Factors that influence human performance as it relates to the safety of a nuclear facility or activities overall phases, including design, construction, commissioning, operation, maintenance and decommissioning.
Some examples are organizational and management structures; policies and programs; allocation offunctions to humans and machines; the design of user interfaces; staffing provisions; job-design features;
work schedules; design of procedures; training; and the physical work environment.
human factors engineering (HFE) (ingénierie des facteurs humains)
See human factors in design.
human factors in design (facteurs humains dans la conception)
The application of knowledge about human capabilities and limitations to a plant, facility, system or
equipment design. Human factors in design ensure that the plant, facility, system or equipment design,
human tasks and work environment, are compatible with the sensory, perceptual, cognitive and physicalattributes of the personnel who operate, maintain and support it. Also called human factors engineering.

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human performance (performance humaine)
The outcomes of human behaviours, functions and actions, in a specified environment, that reflect theability of workers and management to meet a system’s defined performance under the conditions in which
the system will be employed.
human performance management SCA (DSR Gestion de la performance humaine)
A safety and control area (SCA) that covers activities that enable effective human performance throughthe development and implementation of processes that ensure a sufficient number of licensee personnel
are in all relevant job areas and have the necessary knowledge, skills, procedures and tools in place tosafely carry out their duties. This SCA is one of the 14 within the CNSC SCA Framework.
human research study (étude sur des êtres humains)
The administration of unsealed sources (nuclear substances) to, or external irradiation of, humans forpurposes not related to their personal healthcare; includes processing of radiopharmaceuticals andlaboratory studies that are part of the human research study.
HVL (CDA)
See half-value layer.
HVT (CDA)
half-value thickness; see half-value layer
H/X (H/X)
hydrogen-to-fissile atomic ratioI
I (I)
The activity, in becquerel, of any radionuclide that is taken into the body, excluding the radon progeny
and the activity of other radionuclides accounted for in the determination of E. (Source: Radiation
Protection Regulations)
Note: E is the effective dose.
IAEA (AIEA)
See International Atomic Energy Agency.
IAEA Agreement (Accord avec l’AIEA)The Agreement between the Government of Canada and the International Atomic Energy Agency for the
Application of Safeguards in Connection with the Treaty on the Non-proliferation of Nuclear Weapons,
effective on February 21, 1972; INFCIRC/164; UNTS vol. 814, R. No. 11596. (Sources: General Nuclear
Safety and Control Regulations; Class I Nuclear Facilities Regulations)
IAEA inspector (inspecteur de l’AIEA)
See International Atomic Energy Agency inspector.
IAEA Regulations (Règlement de l’AIEA)The Regulations for the Safe Transport of Radioactive Material, published by the IAEA, as amended
from time to time. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
I&C (IC)
instrumentation and control

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ICAO (OACI)International Civil Aviation Organization
ICRP (CIPR)
See International Commission on Radiological Protection.
ICRU (CIUMR)International Commission on Radiation Units and Measurements
IEMP (PISE)
See Independent Environmental Monitoring Program.
IFB (piscine de stockage du combustible usé)
irradiated fuel bay; see wet storage bay
IIP (PIMO)
See integrated implementation plan.
IL (NE)See investigational level.
immediate evacuation zone (zone d’évacuation immédiate)With respect to nuclear criticality safety, the area surrounding a potential criticality accident location thatmust be evacuated without hesitation if a criticality accident alarm signal is activated.
immediate rapid deployment (IRD) (déploiement rapide immédiat [DRI])
With respect to security, the start of an immediate pursuit to make direct contact with an active threat assoon as possible, so as to stop the threat by containment, physical arrest or by use of the appropriate levelof force.
impairment (déficience)With respect to nuclear power plants’ safety-related systems, a failure such that a safety-related system
would operate with reduced redundancy or margin of safety, or would fail to meet its design intent.
Level 1 impairment describes a system state that is impaired to the extent that it would provide inadequate
protection. Level 2 impairment describes a system state that is impaired to the extent that it would provide
some, but not complete, protection for a worst-case process failure. Level 3 impairment describes a
system state where the level of redundancy or margin of safety is reduced but the system is still fully
capable of meeting its design intent.
import (importation)
The transfer of a nuclear substance, prescribed equipment or prescribed information into Canada from aforeign location.
importer (importateur)
A person authorized under the Nuclear Safety and Control Act to import a nuclear substance, prescribedequipment or prescribed information.

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importance measures (mesures d’importance)
With respect to probabilistic safety assessments (PSAs), indices on the importance of an event or group of
events, comprising:• Fussell-Vesely importance: for a specific basic event, the fractional contribution to PSA results for
all accident sequences containing that basic event• risk increase ratio (RIR), also called risk achievement worth (RAW): the factor by which the PSA
results would increase if the basic event is assumed to happen with certainty (failure
probability = 1.0)
• risk decrease ratio (RDR), also called risk reduction worth (RRW): the amount of reduction in the
PSA results to be gained if the basic event is assumed to be available (failure probability = 0.0)
IMRT (RCMI)
intensity modulated radiation therapy
incident (incident)
See event.
incipient failure (début de la défaillance)
A condition of a component that, if left unremedied, could ultimately lead to a degraded or unavailable
component state.
Independent Environmental Monitoring Program (IEMP) (Programme indépendant de surveillanceenvironnementale (PISE))A CNSC program that complements CNSC staff reviews and approvals of licensees’ environmental
monitoring programs and confirms that the public and environment around CNSC-regulated nuclear
facilities are not adversely affected by radiological (nuclear) and non-radiological (hazardous) substances
released to the environment from the facilities. Note: CNSC staff sample air, water, soil, sediment,
vegetation (such as grass) and foodstuffs (such as meat and produce) in public areas outside but in thevicinity of a selected facility. They then analyze the samples and compare contamination levels to federal
and/or provincial guidelines to confirm that the public and the environment in the vicinity are safe andthere are no health effects as a result of facility operations. Some examples of facilities where IEMP
occurs include uranium mines and mills, processing facilities, nuclear power plants, research reactors andwaste management facilities.
independent system (système indépendant)
A system capable of performing its required function while remaining unaffected by the operation or
failure of another system.
Indian (Indien)
See Aboriginal peoples of Canada.
indictable conviction (condamnation pour acte criminel)
A category of conviction under Canada’s Criminal Code reserved for more serious offences such as
murder, acts of terrorism, robbery, drug trafficking, treason and certain types of sexual assaults.
Indigenous peoples (Autochtones)
Includes the First Nations, Inuit and Métis people of Canada. See also Aboriginal peoples of Canada.
indirect (in vitro) radiobioassay (essai biologique indirect [mesures in vitro])
See bioassay.

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indirect bioassay (essai biologique indirect)
See bioassay.
indirect effect (effet indirect)
A secondary environmental effect that occurs as a result of a change that a project may cause in theenvironment. An indirect effect is at least one step removed from a project activity in terms of cause–
effect linkages.
indirect regulatory activities (activités de réglementation indirectes)
Those activities that are in support of direct regulatory activities, such as management, training,
administration, human resources, finance, information technology services and the preparation of
documents, including policies, standards, guides, procedures and notices. (Source: Canadian Nuclear
Safety Commission Cost Recovery Fees Regulations)industrial or research accelerator (accélérateur industriel ou de recherche)
A particle accelerator that is used solely for industrial or research purposes. Note: In instances where
research is to be conducted using an accelerator that is primarily being used for other applications, theaccelerator should be licensed according to its primary intended use.
industrial radiography (gammagraphie industrielle)
The use of certified exposure devices to conduct the non-destructive examination of the structure ofwelds, castings and building components. Also called gamma radiography.
industrial safety accident rate (ISAR) (taux d’accident de travail)A measure of the number of lost-time injuries for a defined number of hours worked. Note: In the
Canadian nuclear power industry, the defined number is 200,000 hours worked by nuclear power plant
personnel. See also lost-time injury.
INES (INES)
See International Nuclear and Radiological Event Scale.
INFCIRC (INFCIRC)
Information Circular (IAEA publication)
informed customer (client informé)
A concept that describes an organization with the capability (expertise and proficiency) to ensure
effective management, control and oversight of nuclear safety (such as health, safety, protection of theenvironment, safeguards and security), including work carried out on its behalf by contractors. Suchorganizations have a clear understanding and knowledge of each product or service being supplied,
specify the requirements for those products and services, oversee the work carried out on its behalf bycontractors, and technically review the output before, during and after the work.
initial conditions (conditions initiales)
The values of variables in a mathematical model that are assumed at the beginning of the time period
considered in the model.
initiating event (événement initiateur)An event that initiates a sequence of events that could lead to a severe accident in the absence of action bya system important to safety, or an event involving a system important to safety that initiates a sequenceof events that could have led to a severe accident if other systems important to safety had not functioned.
See also postulated initiating event.

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initiating parameter (paramètre initiateur)
The physical property being measured or monitored by the triggering device for a special safety system or
its subsystems.
inner area (zone intérieure)An area inside a protected area that is surrounded by a barrier or structure that meets the requirements ofsection 13. (Source: Nuclear Security Regulations)
inner maze entrance (entrée du labyrinthe interne)
The point at which the entrance maze merges with the treatment room containing Class II prescribedequipment.
INPO (INPO)
See Institute of Nuclear Power Operations.
in-service inspection (ISI) (inspection en service)
Non-destructive examination of structures, systems and/or components, performed to provide information
about their current condition and identify any damage, defect or degradation that may have occurred. See
also periodic inspection.
in-service verification (vérification en service)
With respect to nuclear criticality safety, periodic verification of the integrity of a neutron absorbersystem subsequent to installation.
in situ experiment (expérience in situ)
Neutron multiplication or other nuclear reactivity-determining measurement on a subcritical fissile
assembly where protection of personnel against the consequences of a criticality accident is not provided.
This definition applies to nuclear criticality safety.
in vitro bioassay (essai biologique in vitro)
See bioassay.
in vivo bioassay (essai biologique direct [mesures in vivo])
See bioassay.
insider threat (menace interne)
An individual with authorized access to a nuclear facility or a means of transportation, who might attempt
unauthorized removal or sabotage, or who could aid outsiders to do so.
inspection (inspection)
For maintenance purposes, an examination, observation, measurement or test undertaken to assess thecondition of a structure, system or component.
OR
A form of compliance verification independently carried out by the CNSC during which it gathers
information, analyzes data and records results for the purpose of evaluating whether an activity is incompliance with regulatory requirements.
Note: The Commission may designate non-CNSC persons as inspectors; IAEA inspection teams may also
participate in this process.

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inspector (inspecteur)
A person designated as an inspector under section 29. (Source: Nuclear Safety and Control Act)
Note: Inspectors lead inspections of licensed activities. An inspector may be a CNSC employee or aperson otherwise employed under an arrangement with the CNSC.
OR
For safeguards, see International Atomic Energy Agency inspector.
install (installer [montage/démontage])
Mount and dismount a radiation device into its measuring position within a location authorized by alicence (part of the licensed activity of servicing, installation and dismantling of devices containing
radioisotopes).
Institute of Nuclear Power Operations (INPO) (Institute of Nuclear Power Operations [INPO])A not-for-profit organization with the stated mission of promoting the highest levels of safety andreliability in the operation of commercial nuclear power plants. INPO was established by the nuclear
power industry in 1979.
institutional controls (contrôles institutionnels)
The control of residual risks at a site after it has been decommissioned. Institutional controls can include
active measures (those requiring activities on the site such as water treatment, monitoring, surveillance
and maintenance) and passive measures (those not requiring activities on the site, such as land use
restrictions or markers).
instruction (instruction)
See training.
instructional program (programme d’enseignement)
See training program.
instructional strategy (stratégie d’enseignement)
The combination of media, methods and environment used in the delivery of training:• method: the type of learning activity or instructional event• media: the means of delivering instructional activities to the trainee, such as computers or printed
texts• environment: the learning activity’s location, such as a classroom, workplace or home
instrument or article (appareils ou objets)
Any tool, implement or object, or its components, that encloses nuclear substances and that is fabricatedfor a particular use other than solely for enclosing those nuclear substances. (Source: Packaging andTransport of Nuclear Substances Regulations, 2015)
intake (incorporation)
The amount of a radionuclide, measured in becquerels, taken into a body by inhalation, absorption
through the skin, injection or ingestion, or through wounds.
integrated implementation plan (IIP) (plan intégré de mise en œuvre [PIMO])
A plan that considers the scope and schedule of safety improvements to support continued operation of a
facility, based on the results of a periodic safety review.

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integrated system validation (validation des systèmes intégrés)An evaluation, using performance-based tests, to determine whether an integrated system’s design (that is,
hardware, software and personnel elements) meets performance requirements and supports the facility’ssafe operation.
intended end use (utilisation ultime prévue)The declared purpose or use of an imported or exported good or service (for example, industrial
irradiation, industrial radiography, teletherapy, blood irradiation).
intermediate bulk container (IBC) (grand récipient pour vrac [GRV])
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: In the IAEA Regulations, an intermediate bulk container means a portable packaging that has acapacity of not more than 3 m3; is designed for mechanical handling; and is resistant to the stresses
produced in handling and transport, as determined by tests.
intermediate consignee (destinataire intermédiare)
A person who is not the importer but who acts to facilitate the transfer of a nuclear substance, prescribedequipment or prescribed information to the importer within the recipient jurisdiction. However, a person
associated solely with the transport of the nuclear substance, prescribed equipment or prescribed
information (for example, a carrier or freight forwarder) is not considered an intermediate consignee.
intermediate-level waste (déchet de moyenne activité)Radioactive solid waste that typically exhibits levels of penetrating radiation sufficient to require
shielding during handling and interim storage.
internal dosimetry (dosimétrie interne)
See dosimetry types.
internal event (événement interne)
Any event that proceeds from a human error or from a failure of a structure, system or component.
internal hazard (danger interne)
A hazard that originates from the sources located on the site of a nuclear facility (both inside and outsidefacility buildings). Some examples of internal hazards are internal fires, internal floods, turbine missiles,
onsite transportation accidents and releases of toxic substances from onsite storage facilities.
International Atomic Energy Agency (IAEA) (Agence internationale de l’énergie atomique [AIEA])
An independent international organization related to the United Nations system. The IAEA works with its
Member States and multiple partners worldwide to promote safe, secure and peaceful nuclear
technologies. The IAEA reports annually to the UN General Assembly and, when appropriate, to the
Security Council regarding non-compliance by States with respect to their safeguards obligations, as wellas on matters relating to international peace and security.
International Atomic Energy Agency inspector (inspecteur de l’Agence internationale de l’énergie
atomique)
An International Atomic Energy Agency (IAEA) officer appointed by the IAEA Director General,
approved by the IAEA Board of Governors to perform safeguards inspections, and proposed to andaccepted by the Government of Canada to perform safeguards inspections in Canada. IAEA inspectors are
granted privileges and immunities necessary for the performance of their functions. See also inspector.

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International Atomic Energy Agency seal (sceau de l’Agence internationale de l’énergie atomique)
A tamper-indicating device used to join moveable segments of a containment in a way that makes it
difficult to access its contents without opening the seal or breaking the containment. See also
containment.
International Commission on Radiological Protection (ICRP) (Commission internationale deprotection radiologique)
The international organization that has developed standards and concepts for ionizing radiation
protection.
International Maritime Dangerous Goods Code (Code maritime international des marchandises
dangereuses)
The document of that name published by the International Maritime Organization, as amended from time
to time. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
International Nuclear and Radiological Event Scale (INES) (Échelle internationale des événements
nucléaires et radiologiques [INES])
A seven-point scale used to promptly and consistently classify nuclear events into safety-significant
ratings.
International Reporting System for Operating Experience (IRS) (Système international de
notification des incidents [IRS])
A platform for the collection, processing and effective dissemination of construction, operating anddecommissioning experience information among regulators in IAEA Member States.
interoperability (interopérabilité)
The capacity to manage and communicate electronic product and project detail between collaborating
firms and within individual companies’ design, construction, operations, maintenance, and businessprocess systems.
intervenor (intervenant)A person who is permitted to intervene at a public hearing under rule 19. (Source: Canadian Nuclear
Safety Commission Rules of Procedure).
Note: The intervenor is a person who has an interest, expertise or information useful to the Commissionin coming to a decision.
interviewer (intervieweur)With respect to security, a qualified person, representing a licensee, who conducts investigations and/or
security interviews to gather information from an applicant for, or holder of, site access security clearance(SASC), for the purpose of granting, renewing, denying or revoking the SASC.
Inuit (Inuit)
See Aboriginal peoples of Canada or Indigenous peoples.
inventory change (variation de stock)
With respect to safeguards, means an increase or decrease of nuclear material, in terms of batches, in amaterial balance area. An internal inventory change affects only one material balance area. See alsomaterial balance area.

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inventory difference (différence d’inventaire)With respect to nuclear material accounting, the difference between book-adjusted inventory and thephysical inventory as reported in the reconciliation statement. Also called material unaccounted for.
inventory verification (vérification du stock)See physical inventory verification.
investigational level (IL) (niveau d’enquête [NE])An indicator of intake (in becquerels) of a radioactive substance that requires special monitoring of aworker. Typically the level is expressed as a fraction of the annual limit on intake.
ion exchange process (procédé d’échange d’ions)
A usually reversible exchange of one ion with another, either on a solid surface or within a lattice. Ion
exchange is a commonly used method for treating liquid waste.
ionizing radiation (rayonnement ionisant)For the purposes of radiation protection, radiation capable of producing ion pairs in biological material(s).
Note: Ionizing radiation is constantly present in the environment and includes the radiation that comesfrom both natural and artificial sources, such as cosmic rays, terrestrial sources (radioactive elements inthe soil), ambient air (radon), and internal sources (food and drink).
IP-1 package (colis CI-1)
See Type IP-1.
IP-2 package (colis CI-2)
See Type IP-2.
IP-3 package (colis CI-3)
See Type IP-3.
IPPAS (SCIPP)
International Physical Protection Advisory Service
IRD (DRI)
See immediate rapid deployment.
irradiated fuel bay (piscine de combustible usé)
See wet storage bay.
irradiated nuclear fuel (combustible nucléaire irradié)
See used nuclear fuel.
irradiation (irradiation)
Exposure to radiation. Note: “exposure” is commonly used to describe radiation doses to people while“irradiation” is more often used for radiation doses to food or industrial objects.

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irradiator (irradiateur)A device that is designed to contain a nuclear substance and to deliver controlled doses of radiation to any
target material except persons. (Source: General Nuclear Safety and Control Regulations)OR
A device that is designed to contain a nuclear substance and to deliver controlled doses of radiation fromthat substance to any target except persons. (Source: Class II Nuclear Facilities and Prescribed
Equipment Regulations)
IRRS (SEIR)
Integrated Regulatory Review Service
IRS (IRS)
See International Reporting System for Operating Experience.
ISAR (ISAR)
See industrial safety accident rate.
ISI (inspection en service)
See in-service inspection.
island load (îlotage)
See house load operation.
island operation (fonctionnement en îlotage)
See house load operation.
ISO (ISO)International Organization for Standardizationisocentre (isocentre)
For teletherapy equipment, the intersection between the central axis of the primary beam and the axis ofgantry rotation.
isolation (isolement)
With respect to radioactive waste, means the physical separation of this waste from people and theenvironment to make access to the waste difficult. Note: For deep geological disposal, isolation isprovided mainly by the depth of the repository.
isotope (isotope)
A variation in the form of atoms, of the same chemical element, which are distinguished by the number ofneutrons in the nucleus. The number of protons remains the same, but the number of neutrons differs. For
example, uranium has 16 different isotopes.
isotope production accelerator (accélérateur pour la production d’isotopes)
A particle accelerator that is designed and used for producing nuclear substances by irradiating a target
material.
ISR (EIS)
integrated safety review; see periodic safety review

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item (article)
With respect to nuclear material accounting, an individually identifiable unit of nuclear material (forexample, a fissile assembly or material in bulk form in a container, such as a tank or box, that is kept
intact while stored in the material balance area).
items important to safety (dispositifs importants pour la sûreté)
An item that is part of a safety group and/or whose malfunction failure could lead to radiation exposure.

J
jet impact (impact d’un jet)
The potential internal hazard associated with high-pressure fluid released from a pressure-retaining
component.
job (emploi)
The work performed by an incumbent in a position or by a group of incumbents in a position who
perform essentially the same duties and tasks and require similar knowledge, skills and safety-related
attributes to perform those tasks.
jurisdiction (instance)[For Class I nuclear facilities, m]eans(a) a federal authority;(b) any agency or body that is established under an Act of Parliament and that has powers, duties orfunctions in relation to an assessment of the environmental effects of the preparation of a site for aClass I nuclear facility or its construction, operation, decommissioning or abandonment;(c) the government of a province;(d) any agency or body that is established under an Act of the legislature of a province, and that has
powers, duties or functions in relation to an assessment of the environmental effects of the
preparation of a site for a Class I nuclear facility or its construction, operation, decommissioning or
abandonment;(e) any body that is established under a land claims agreement referred to in section 35 of theConstitution Act, 1982, and that has powers, duties or functions in relation to an assessment of theenvironmental effects of the preparation of a site for a Class I nuclear facility or its construction,
operation, decommissioning or abandonment;(f) a governing body that is established under legislation that relates to the self-government of Indians
and that has powers, duties or functions in relation to an assessment of the environmental effects ofthe preparation of a site for a Class I nuclear facility or its construction, operation, decommissioning
or abandonment;(g) a government of a foreign state or of a subdivision of a foreign state, or any institution of such agovernment; and(h) an international organization of states or any institution of such an organization.
(Source: Class I Nuclear Facilities Regulations)
OR[For uranium mines and mills, m]eans(a) a federal authority;(b) any agency or body that is established under an Act of Parliament and that has powers, duties orfunctions in relation to an assessment of the environmental effects of the preparation of a site for auranium mine or mill or its construction, operation, decommissioning or abandonment;(c) the government of a province;73

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REGDOC-3.6, Glossary of CNSC Terminology(d) any agency or body that is established under an Act of the legislature of a province, and that has
powers, duties or functions in relation to an assessment of the environmental effects of the
preparation of a site for a uranium mine or mill or its construction, operation, decommissioning or
abandonment;(e) any body that is established under a land claims agreement referred to in section 35 of theConstitution Act, 1982, and that has powers, duties or functions in relation to an assessment of theenvironmental effects of the preparation of a site for a uranium mine or mill or its construction,
operation, decommissioning or abandonment;(f) a governing body that is established under legislation that relates to the self-government of Indians
and that has powers, duties or functions in relation to an assessment of the environmental effects ofthe preparation of a site for a uranium mine or mill or its construction, operation, decommissioning or
abandonment;(g) a government of a foreign state or of a subdivision of a foreign state, or any institution of such agovernment; and(h) an international organization of states or any institution of such an organization.
(Source: Uranium Mines and Mills Regulations)Kkeff
See effective multiplication factor.
key measurement point (KMP) (point de mesure principal [PMP])
A location where nuclear material appears in such a form that it may be measured to determine material
flow or inventory. Key measurement points therefore include, but are not limited to, the inputs andoutputs (including measured discards) and storage in material balance areas.
KI (KI)
potassium iodide
KMP (PMP)
See key measurement point.
knowledge (connaissance)
The theoretical and/or practical understanding of a subject matter required to perform work.

Llabel (étiquette)
With respect to nuclear material accounting, a unique three- or four-digit number used to clearly identify
information (for example, hazardous materials).
lapel sampler (échantillonneur d’air personnel[EAP])
See personal air sampler.
large object (objet de grande dimension)
An object that has been decommissioned from a nuclear facility, that is internally contaminated with
nuclear substances meeting the requirements applicable to an SCO-I or SCO-II as set out in the IAEA
Regulations and that cannot be transported in a type of package described in these Regulations due to its
dimensions. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)74

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LBB (FAR)
See leak before break.
LBLOCA (APRPGB)
large-break loss-of-coolant accident; see loss-of-coolant accident.
LCH (MCP)
licence conditions handbook
LCMP (PGV)
lifecycle management plan; see aging management program / aging management plan
LDRM (MRFD)
See low dispersible radioactive material.
leak before break (LBB) (fuite avant rupture[FAR])
Leakage from a flaw in a pressurized component (such as a pipe) during normal operation of a nuclear
reactor, detected early enough for the reactor to be shut down and depressurized before the flaw grows
large enough to cause a rupture.
leak test (épreuve d’étanchéité)With respect to sealed sources (including sealed sources within prescribed equipment) or nuclear
substances used as shielding, a method of verifying the integrity of the encapsulation of the sealed sourceor ensuring that the nuclear substance used for shielding is not readily removable from the surface of thatshielding.
learning (apprentissage)
A change in behaviour that occurs as a result of the acquisition of knowledge, skills or safety-related
attributes.
learning organization (organisation axée sur l’apprentissage)
A work environment where people continually build on their capability to reach their goals. In a learningorganization, new and challenging ways of interacting and behaving are encouraged in order to meet
future organizational challenges, and everyone has the opportunity to make sense of their work together.
legacy site (site hérité)
In Canada, legacy sites specifically refer to research and demonstration facilities, locations or sites datingback to the birth of nuclear technologies in Canada for which decommissioning was not planned as part ofthe design
lesson plan (plan de cours)
A guide that instructors use to ensure that training is specific and goal oriented.
LET (TLE)
linear energy transfer
LEU (UFE)
See low-enriched uranium.
licence (permis)
A licence issued under section 24. (Source: Nuclear Safety and Control Act)75

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Note: This legal document issued by the Commission or a designated officer allows an activity (defined
under section 26) to be carried out. The NSCA authorizes the Commission and, in some cases, designatedofficers to grant licences for purposes listed in section 26 of the NSCA.
licence purpose (objet du permis)
A particular use of nuclear substances as described in the Canadian Nuclear Safety Commission Cost
Recovery Fees Regulations.
licensed activity (activité autorisée)An activity described in any of paragraphs 26(a) to (f) of the Act that a licence authorizes the licensee tocarry on. (Sources: General Nuclear Safety and Control Regulations; Radiation Protection Regulations)OR
An activity described in paragraph 26(e) of the Act that a licence authorizes the licensee to carry on in
relation to a Class I nuclear facility. (Source: Class I Nuclear Facilities Regulations)OR
An activity described in paragraph 26(a), (c) or (e) of the Act that a licence authorizes the licensee tocarry on in relation to a Class II nuclear facility or Class II prescribed equipment. (Source: Class II
Nuclear Facilities and Prescribed Equipment Regulations)OR
An activity described in any of paragraphs 26(a) to (c) of the Act that a licence authorizes the licensee tocarry on in relation to a nuclear substance or a radiation device. (Source: Nuclear Substances andRadiation Devices Regulations)OR
An activity described in paragraph 26(e) of the Act that a licence authorizes the licensee to carry on in
relation to a uranium mine or mill. (Source: Uranium Mines and Mills Regulations)licensee (titulaire de permis)
Note: In the regulations below, a person may be an individual or organization.
A person who is licensed to carry on an activity described in any of paragraphs 26(a) to (f) of the Act.
(Sources: General Nuclear Safety and Control Regulations; Radiation Protection Regulations)OR
A person who is licensed to carry on an activity described in paragraph 26(e) of the Act in relation to a
Class I nuclear facility. (Source: Class I Nuclear Facilities Regulations)OR
A person who is licensed to carry on an activity described in any of paragraphs 26(a), (c) or (e) of the Act
in relation to a Class II nuclear facility or Class II prescribed equipment. (Source: Class II Nuclear
Facilities and Prescribed Equipment Regulations)OR
A person who is licensed to carry on an activity described in any of paragraphs 26(a) to (c) of the Act inrelation to a nuclear substance or a radiation device. (Source: Nuclear Substances and Radiation Devices
Regulations)OR76

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Means(a) in this section and sections 2 to 7.2, a person who is licensed to carry on an activity described in anyof paragraphs 26(a), (b), (e) or (f) of the Act in relation to Category I, II or III nuclear material or a
nuclear power plant;(b) in sections 7.3 to 38, a person who is licensed to carry on an activity described in any ofparagraphs 26(a), (b), (e) or (f) of the Act in relation to a high-security site; and(c) in Part 2, a person who is licensed to carry on an activity described in any of paragraphs 26(a), (b) or(e) of the Act in relation to a nuclear facility set out in column 2 of Schedule 2.
(Source: Nuclear Security Regulations)
Note: In paragraph (a) above, “in this section” refers to section 1 of the Nuclear Security Regulations.
OR
A person who is licensed to carry on an activity described in paragraph 26(e) of the Act in relation to auranium mine or mill. (Source: Uranium Mines and Mills Regulations)licensee documents requiring notification of change (documents de permis nécessitant un avis dechangement)
Licensee documents for which the licensee is required to notify the CNSC, in writing, when changes are
made. These documents are typically identified in the licence conditions handbook.
licensing (processus d’autorisation)
Activities for processing and assessing an application related to a licence or certificate or a request for an
approval prior to issuing, denying, renewing, amending or replacing the licence, certificate or approval.
This includes similar work prior to suspending or revoking a licence or certificate.
licensing basis (fondement d’autorisation)
A set of requirements and documents for a regulated facility or activity comprising:• the regulatory requirements set out in the applicable laws and regulations• the conditions and safety and control measures described in the facility’s or activity’s licence and the
documents directly referenced in that licence• the safety and control measures described in the licence application and the documents needed tosupport that licence application
lifecycle management plan (LCMP) (programme ou plan de gestion du vieillissement [PGV])
See aging management program / aging management plan.
lifecycle of a nuclear facility (cycle de vie d’une installation nucléaire)
The various stages of a nuclear facility’s lifespan, including site selection, site preparation, construction,
operation, decommissioning and abandonment.
lifecycle planning (planification du cycle de vie)
A planning process for decommissioning that begins in the design and construction phases of a facility,
remains responsive to new information obtained during operations, culminates in a detailed plan for
CNSC approval at the end of operations, and remains flexible and adaptive to conditions encounteredduring the actual decommissioning process.

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limit of operating envelope (LOE) (enveloppe limite d’exploitation [ELE])
An assumption, used in a deterministic safety analysis, that, prior to a postulated accident, a nuclear
facility was operating with some of the important plant operating parameters being at their safety limits,
while some of the models used to describe the event may be conservative. Note: LOE does notnecessarily mean an impossible plant operating state. However, depending on the number and nature of
the conservative assumptions made in the analysis, the event may become highly improbable, if not
physically impossible.
LLOCA (APMRP)
large loss-of-coolant accident; see loss-of-coolant accident
LLRD (PRLP)
long-lived radioactive dust
LLW (DFA)See low-level waste.
LOCA (APRP)
See loss-of-coolant accident.
location (emplacement)
With respect to nuclear substances and radiation devices, any room, area, enclosure, land or base(s) ofoperations the licensee occupies where the licensee uses or stores nuclear substances for more than
90 consecutive days per calendar year. The location may be identified by a postal address or global
positioning system coordinates.
location outside facilities (LOF) (emplacement hors installations)
Any installation or location, other than a facility, where nuclear material is customarily used in amountsof one effective kilogram or less and is subject to full nuclear material accounting and reporting.
locked position (position verrouillée)
For exposure devices, the condition of a sealed source assembly, with either an exposure container orsource changer, in the secured and locked position.
LOE (ELE)
See limit of operating envelope.
LOF (emplacement hors installations)
See location outside facilities.
logging (diagraphie)
The use of sealed sources to obtain subsurface geological information.
long term (long terme)With respect to disposal of radioactive waste or of mineralized waste rock and tailings, any period of timeafter which active institutional controls can be expected to cease.
long-term management of nuclear waste (gestion à long terme des déchets nucléaires)
The long-term management of radioactive nuclear waste by means of storage or disposal, including
handling, treatment, conditioning or transport for the purpose of storage or disposal. Also called
long-term waste management.

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long-term operation (LTO) (exploitation à long terme)
The operation, beyond the originally intended operating life of a reactor facility, which has been justified
by a safety assessment that considers life-limiting processes and features for structures, systems andcomponents.
long-term safe stable state (état stable et sûr à long terme)
A state in which fuel in the core or the spent fuel pool is submerged in water, the associated reactivity iscontrolled to remain subcritical, and a long-term decay heat removal from the fuel is achieved andmaintained.
long-term waste management (gestion à long terme des déchets)
See long-term management of nuclear waste.
loss-of-coolant accident (LOCA) (accident de perte de réfrigérant primaire [APRP])
A type of reactor accident that results from a loss of coolant due to a break in the primary heat transportsystem.
lost days (jours perdus)
The number of calendar days, recommended by a physician or other healthcare professional, that an
employee is unable to work beyond the day of injury or illness. Lost time ends as of the date that theemployee is deemed fit to work either full or restricted work, or up to a maximum of 180 calendar days
for any individual case.
lost-time injury (accident entraînant une perte de temps de travail)An injury or illness resulting in lost days beyond the date of injury as a direct result of an occupational
injury or illness incident.
low dispersible radioactive material (LDRM) (matière radioactive faiblement dispersable [MRFD])
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
low-enriched uranium (LEU) (uranium faiblement enrichi [UFE])
Enriched uranium containing less than 20 percent by weight of isotope uranium-235, uranium-233, or
combined uranium-233 and uranium-235.
low-level waste (LLW) (déchet de faible activité [DFA])
Radioactive solid waste that contains material with radionuclide content above established clearance
levels and exemption quantities, but that generally has limited amounts of long-lived activity.
low toxicity alpha emitters (émetteurs alpha de faible toxicité)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
LPO (bouton de délai)last person out
LPSWOS (CESBP)
low-pressure service water open system
LRF (FGER)
large release frequency

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LSA material (matière LSA)
Has the meaning assigned by the definition “low specific activity (LSA) material” in the IAEA
Regulations. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
LTO (exploitation à long terme)
See long-term operation.
LWR (REO)
light-water reactorMmain control room (MCR) (salle de commande principale [SCP])
A room where operations personnel can centrally monitor and control facility systems.
maintenance (entretien)
The organized activities, both administrative and technical, to keep Class II prescribed equipment andradiation devices, as well as structures, systems and components, in good operating condition. Note: For
reactor facilities, maintenance includes repair aspects.
malevolent act (acte malveillant)
An illegal action or an action that is committed with the intent of causing wrongful harm.
management (gestion)
In relation to nuclear fuel waste, long-term management by means of storage or disposal, including
handling, treatment, conditioning or transport for the purpose of storage or disposal. (Source: Nuclear
Fuel Waste Act)OR
A functional area that groups 3 of the 14 safety and control areas (SCAs) within the CNSC SCA
Framework: management system, human performance management and operating performance. Other
functional areas are “core control processes” and “facility and equipment”.
management measures (mesures de gestion)
With respect to nuclear criticality safety, functions performed by a licensee, generally on a continuingbasis, on nuclear criticality safety controls, to ensure the controls are available and reliable to performtheir functions when needed. Management measures include configuration management, maintenance,
training and qualifications, procedures, audits and assessments, event investigations, records
management, and other quality assurance elements.
management system (système de gestion)
With respect to packaging and transport of nuclear substances, has the same meaning as in the IAEA
Regulations. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
Note: In the IAEA Regulations, a management system means a set of interrelated or interacting elements(system) for establishing policies and objectives and enabling the objectives to be achieved in an efficientand effective manner.
OR
The framework of processes, procedures and practices used to ensure that an organization can fulfill alltasks required to achieve its objectives safely and consistently.

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management system SCA (DSR Système de gestion)
A safety and control area (SCA) that covers the framework that establishes the processes and programs
required to ensure an organization achieves its safety objectives, continuously monitors its performanceagainst these objectives, and fosters a healthy safety culture. This SCA is one of the 14 within the CNSCSCA Framework.
MAPS (normes de performance minimales permises)
See minimum allowable performance standards.
material balance area (MBA) (zone de bilan matières [ZBM])
An area within a facility or a location outside a facility where both of the following conditions apply:• the quantity of nuclear material in each transfer to and from the area can be determined• the physical inventory of nuclear material within the area can be determined when necessary, in
accordance with specified procedures, so that the material balance can be established for IAEA
safeguards purposesmaterial balance period (période de bilan matières)The time between two consecutive physical inventory takings.
material category (catégorie d’élément des matières nucléaires)
With respect to nuclear material accounting, any one of the following:• any of these element material categories – natural uranium, depleted uranium, enriched uranium,
thorium and plutonium• any of these isotope material categories – uranium-235, uranium-233 and plutonium-239
material description code (MDC) (code de description de matière [CDM])
With respect to nuclear material accounting, a four-character code used to describe nuclear materialbatches by physical form, chemical composition, containment or type of container, and by irradiation
status and quality.
material unaccounted for (MUF) (différence d’inventaire)
See inventory difference.
MBA (ZBM)
See material balance area.
MB Code (code MB)
See measurement basis code.
MBq (MBq)
megabecquerel, that is, 106 becquerels; see becquerel.
MCR (SCP)
See main control room.
MDC (CDM)
See material description code.

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measurement basis code (MB Code) (measurement identification code) (code de type de mesure[code de base de mesure])
The data element for the method used to measure or determine the weight or mass data of a nuclear
material element and isotope. The MB Code indicates whether weight data was determined in the current
material balance area (MBA) or another MBA and whether the data was new or previously reported.
measurement uncertainty (incertitude relative à la mesure)
The amount by which a measured value may vary from the actual physical value of a parameter at thetime of measurement.
medical linear accelerator (accélérateur linéaire médical)
An accelerator that produces a collimated beam of high-energy photons (X-rays) that are used to deliver
controlled doses of radiation for therapeutic purposes.
medical review officer (MRO) (médecin examinateur[ME])With respect to fitness for duty, a person who is a licensed physician and board-certified as a medical
review officer responsible for receiving and reviewing laboratory results generated by an employer’s drug
testing program and evaluating medical explanations for certain drug test results.
medically treated injury (accident nécessitant des soins médicaux)
An injury or illness beyond a first aid injury, where there have been no lost days that are the direct resultof an occupational injury or illness incident.
megabecquerel (mégabecquerel)
106 becquerels; see becquerel.
member (commissaire)
A member of the Commission appointed under section 10 of the Act. (Source: Canadian Nuclear Safety
Commission By-laws)
Métis (Métis)See Aboriginal peoples of Canada or Indigenous peoples.
MeV (MeV)
megaelectron volt
microsievert (µSv) (microsievert [µSv])
One-millionth of a sievert.
mill (usine de concentration)
A facility at which ore is processed and treated for the recovery of uranium concentrate, including any
tailings-handling and water treatment system associated with the facility. (Source: Uranium Mines andMills Regulations)millisievert (mSv) (millisievert [mSv])
One-thousandth of a sievert.
mine (mine)
An excavation site and a removal site. (Source: Uranium Mines and Mills Regulations)
Note: A mine includes both these sites.

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mineralized waste rock (stériles minéralisés)Rock with the potential to release hazardous and/or nuclear substances that could significantly harm
human health or the environment. Mineralized waste rock may be further segregated based onradiological content, contaminants of concern (such as nickel or arsenic), and acid-generating potential.
Also called special waste rock.
mine waste (résidu minier)
Waste that includes tailings and mineralized waste rock but not overburden or clean rock.
minimum accident of concern (accident préoccupant le moins grave)With respect to nuclear criticality safety, an accident resulting in a dose to free air of 0.20 gray in the firstminute at a distance of 2 metres from the reacting material.
minimum allowable performance standards (MAPS) (normes de performance minimales permises)
The set of operating limits or the range of conditions, established for components or subsystems, which
define the minimum acceptable states for those components or subsystems credited in a safety analysis.
minimum measurable concentration (MMC) (concentration minimale mesurable [CCM])
The smallest amount (activity or mass) of a radionuclide (or analyte) in a sample that will be detectedwith a probability β of non-detection while accepting a probability α of erroneously deciding that apositive (non-zero) quantity of analyte is present in an appropriate blank. MMC is measured in becquerels
per litre.
minimum shift complement (effectif minimal par quart)
See minimum staff complement.
minimum staff complement (effectif minimal par quart)
The minimum number of qualified workers who must be present at all times to ensure the safe operationof a nuclear facility and its adequate emergency response capability. Note: Also called minimum shiftcomplement. While shift and staff have similar meanings, shift is used in power reactor operating
licences.
minimum testing level (MTL) (niveau minimal d’essai [NME])
The smallest amount of radioactive material that a dosimetry service must be able to measure as part of an
independent testing program.
Minister (ministre)
The Minister of Natural Resources or such member of the Queen’s Privy Council for Canada as theGovernor in Council may designate as the Minister for the purposes of this Act. (Source: Nuclear Safety
and Control Act)
misconnect (mauvaise connexion)
For exposure devices, a condition in which a remote control can be attached to an exposure container
without attaching the control cable to the sealed source assembly.
missile generation (formation de missiles)
The hazard associated with the sudden high-speed propulsion of debris.
mission time (temps de mission)
The duration within which a system or component is required to operate or be available to operate andfulfill its function following an event.

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mitigation (mesures d’atténuation)
Measures aimed at eliminating, reducing or controlling the adverse effects of a licensed activity,
substance, equipment or facility. Mitigation may include restitution for any damage caused by such
effects, such as through replacement, restoration or compensation.
mitigative control (contrôle atténuateur)
A control intended to reduce the consequences of an accident sequence, not to prevent it. When amitigative control works as intended, the results of the sequence are called the mitigated consequences.
MMC (CMM)
See minimum measurable concentration.
MMR (MRM)
Micro modular reactor; see reactor facility.
modelling parameters (paramètres de modélisation)
With respect to environmental risk assessment, numerical values used to characterize properties ofcontaminants (such as an octanol-water partitioning coefficient) and environmental media (such as anorganic matter fraction of soil) that are used in models to predict the environmental fate and transport ofcontaminants.
modelling uncertainties (incertitudes relatives à la modélisation)
Uncertainties associated with the models and correlations embedded in a computer code and that
represent the physics of the problem, the solution scheme, data libraries and inherent deficiencies of thecomputer program.
moderation (modération)
The process of decreasing the energy of neutrons through successive collisions with moderator nuclei
without appreciable competing capture.
moderator (modérateur)
A material used to slow down or “moderate” neutrons produced by the nuclear fuel. The moderator
reduces neutron energy by scattering without appreciable capture. Materials of prime concern are thosecontaining light nuclei with large scattering cross-sections and relatively low absorption cross-sections.
moderator control area (zone de contrôle des modérateurs)
An area defined by a nuclear criticality safety evaluation in which moderators are limited and controlled
for nuclear criticality safety.
moderator control engineered barrier (barrière artificielle de contrôle du modérateur)A physical feature of a system specifically identified and used to limit or control the introduction ofmoderators for nuclear criticality safety. Some examples of typical moderator control engineered barriers
are secondary roofs, false ceilings, secondary walls, vapour barriers, raised floors or structure, normallyclosed apertures, and seals.
modified Kusnetz method (méthode de Kusnetz modifiée)
A method of determining and expressing atmospheric concentrations of radon progeny in terms of latentalpha energy. This method requires the use of an alpha counter equipped with an electronic scaler tomeasure the emission of alpha particles.

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monitoring (contrôle)
See condition monitoring.
mood-altering substance (substance psychoactive)
Any product that, whether legally or illegally used, results in cognitive or physical limitations thatnegatively impact performance on the job.
MRO (ME)See medical review officer.
MSDS (FS)material safety data sheet (associated with Workplace Hazardous Materials Information System)
MSIV (VIPV)
main steam isolation valve
MTL (NME)
See minimum testing level.
MTU (MTU)
metric tonne of uranium
MU (UM)
monitor unit
MUF (différence d’inventaire)material unaccounted for; see inventory differenceN
National Dose Registry (NDR) (Fichier dosimétrique national [FDN])
The centralized database of occupational radiation exposure records, managed, updated and maintainedby the Radiation Protection Bureau of Health Canada. The NDR publishes annual reports on occupationaldose information and trends, according to job type, over the lifetime of registered individuals.
National Non-Destructive Testing (NDT) Certification Body (NCB) (Organisme de certification
national [OCN] en essais non destructifs [END])
The division of Natural Resources Canada that administers, on behalf of the CNSC, the written
examination for candidates for the position of exposure device operator.
natural analogues (analogues naturels)
Natural conditions or processes, occurring over long periods of time, that are the same as or similar to
those known or predicted to occur in some part of a waste management system.
natural phenomenon event (phénomène naturel)
An earthquake, flood, tornado, tsunami, hurricane or other event that occurs in the natural environmentand could adversely affect safety. Natural phenomenon events may be credible or incredible, dependingon their likelihood of occurrence.

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natural uranium (uranium naturel)
Uranium that contains uranium-235 in a concentration that is normally found in nature. (Source: Nuclear
Substances and Radiation Devices Regulations)
Note 1: With respect to nuclear criticality safety, this concentration of this isotope is equal to or less than
0.71 percent by weight.
Note 2: With respect to packaging and transport of nuclear substances, natural uranium means uranium(which may be chemically separated) containing the naturally occurring distribution of uranium isotopes(approximately 99.28 percent uranium-238, and 0.72 percent uranium-235 by mass). A very small masspercentage of uranium-234 is present.
NCB (OCN)
See National Non-Destructive Testing (NDT) Certification Body.
NCS (SCN)
See nuclear criticality safety.
NCSE (ESCN)
nuclear criticality safety evaluation
NCS staff (personnel de SCN)
See nuclear criticality safety staff.
NDR (FDN)
See National Dose Registry.
NDT (END)
non-destructive testing; see also National Non-Destructive Testing (NDT) Certification Body
NEM (GUN)
See nuclear emergency management.
NEO (OUN)
See Nuclear Emergency Organization.
neutron (neutron)
A subatomic particle found in the nucleus of atoms. A neutron has a mass of about 1.6 x 10-27 kg and noelectric charge.
neutron absorber (absorbeur de neutrons)
A neutron-capture material; that is, a substance with a large neutron absorption cross-section. Whenneutron absorption is not desired, a neutron absorber may be called a neutron poison. Some examples ofneutron absorbers are:• boron, used in some shutdown systems• some of the products generated during fission that have a high neutron absorption cross-section, suchas xenon-135 and samarium-149
neutron absorber system (système absorbeur de neutrons)
Any combination of fixed neutron absorbers, fixed moderators, and other materials with an assigned
nuclear criticality safety function.

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neutron multiplication (multiplication des neutrons)
The process in which a neutron produces on the average more than one neutron in a medium containing
fissile material.
neutron poison (poison neutronique)
See neutron absorber.
neutron radiation (rayonnement neutronique)
Radiation that involves free neutrons (unstable subatomic particles with no electric charge) released fromatoms during the nuclear fission or fusion process. When absorbed into an atom, the free neutrons canmake that atom unstable, and more likely to decay and produce ionizing radiation. Neutron radiation has ahigh penetrating capability.
NEW (TSN)
See nuclear energy worker.
night shift (quart de nuit)
Shift that includes any time at work between 2 a.m. and 6 a.m.
NOA (avis d’évaluation – RIEN À SIGNALER )See NOA – NO ADVERSE INFO or Notice of Assessment (NOA) – INSUFFICIENT INFO.
NOA – NO ADVERSE INFO (avis d’évaluation – RIEN À SIGNALER)
A notice of assessment issued by the Canadian Security Intelligence Service, indicating that there is no
adverse information regarding an applicant’s loyalty to Canada.
non-fixed contamination (contamination non fixée)
As defined in the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
Note: In the IAEA Regulations, non-fixed contamination means contamination that can be removed froma surface during routine conditions of transport.
non-ionizing radiation (rayonnement non ionisant)Radiation that has a lower energy level than ionizing radiation and cannot remove an electron from anatom and produce ions. Examples include ultraviolet (UV), visible light, infrared, microwaves and radio
waves. This type of radiation is not regulated by the Nuclear Safety and Control Act.
non-routine bioassay (essai biologique spécial)
Any bioassay that is implemented as part of an ad hoc response to a particular circumstance, such as aknown or suspected intake of radioactive material due to an abnormal incident in the workplace. Also
called ad hoc bioassay; special bioassay.
non-safeguarded material (matières non visées par les garanties)
Source material and special fissionable material under IAEA safeguards (agreement INFCIRC/164) thathas not reached the stage of the nuclear fuel cycle as described in article 34(c) of the agreement.
non-stochastic effect (effet non stochastique)
See deterministic effect.

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normal operation (exploitation normale)The operation of a nuclear facility within specified operational limits and conditions, including (whereapplicable) start-up, power operation, shutting down, shutdown, maintenance, testing and refuelling. In
nuclear reactors, normal operation is a plant state.
Notice of Assessment (NOA) – INSUFFICIENT INFO (avis d’évaluation – RENSEIGNEMENTS
INSUFFISANTS)
A notice of assessment issued by the Canadian Security Intelligence Service (CSIS) indicating that there
is insufficient information for CSIS to provide a meaningful assessment on the loyalty to Canada of an
applicant for site access security clearance, usually due to lack of traceable history or residency.
NPP (centrale nucléaire)
See nuclear power plant.
NPT (TNP)
Treaty on the Non-Proliferation of Nuclear Weapons (also referred to as the Non-Proliferation Treaty or
the Nuclear Non-Proliferation Treaty).
NRC (CNRC ou NRC des États-Unis)
National Research Council or see U.S. Nuclear Regulatory Commission.
NSCA (LSRN)
See Nuclear Safety and Control Act.
NSG (GFN)
See Nuclear Suppliers Group.
NSO (ASN)
See nuclear security officer.
nuclear activity
See activity or licensed activity.
nuclear and nuclear-related dual-use items (articles à caractère nucléaire et articles à double usage
dans le secteur nucléaire)
Categories in the Nuclear Non-proliferation Import and Export Control Regulations that group controlled
nuclear substances, equipment and information. Part A of the schedule in the Regulations lists nuclear
items under each of these three categories, and Part B lists nuclear-related dual-use items under the same
categories. Note: The term dual use refers to the potential for a nuclear-related item to be used not only incivilian applications, but also in a nuclear weapons program. Also called controlled nuclear substances,equipment and information. See also controlled nuclear equipment; controlled nuclear information;
controlled nuclear substance.
nuclear criticality (criticité nucléaire)
A self-sustaining chain reaction of nuclear fission. (Source: Nuclear Substances and Radiation Devices
Regulations)
Note: With respect to nuclear criticality safety, pertaining to a system that supports a sustained fission
chain reaction.

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nuclear criticality process evaluation (évaluation de procédé en matière de criticité nucléaire)
A document that identifies and defines all known nuclear criticality safety concerns; documents nuclear
criticality safety assumptions, requirements, limits and controls; and demonstrates subcriticality. Also
called process evaluation.
nuclear criticality safety (NCS) (sûreté-criticité nucléaire [SCN])
Protection against the consequences of a criticality accident, preferably by prevention of the accident.
nuclear criticality safety control (contrôle de sûreté-criticité nucléaire)
Structures, systems, equipment, components, and activities of personnel that are relied on to prevent
accidents at a facility or to mitigate their potential consequences. Also called criticality safety control.
Note: This control does not limit the licensee from identifying additional structures, systems, equipment,
components, or activities of personnel (that is, beyond those in the minimum set necessary for compliancewith the performance requirements) as items relied on for safety. All safety controls (active engineered
control, passive engineered control, simple administrative control and enhanced administrative control)
are nuclear criticality safety controls.
nuclear criticality safety staff (NCS staff) (personnel de sûreté-criticité nucléaire [personnel de SCN])
Specialists skilled in the techniques of nuclear criticality safety assessment and familiar with plant
operations while, to the extent practicable, administratively independent of process supervision. Also
called criticality safety staff.
nuclear emergency (urgence nucléaire)
An abnormal situation that may increase the risk of harm to the health and safety of persons, theenvironment or national security, and that requires the immediate attention of the CNSC. Some examples
are an emergency at a nuclear facility; an emergency involving a nuclear-powered vessel in a Canadian
port; an emergency involving the loss, theft or discovery of radioactive material; or a terrorist attack using
radioactive material.
nuclear emergency management (NEM) (gestion des urgences nucléaires [GUN])
The organized effort to prevent, prepare for, respond to and recover from a nuclear emergency.
nuclear emergency management program (programme de gestion des urgences nucléaires)
The comprehensive program described by the CNSC’s nuclear emergency management policy document
together with the nuclear emergency management plan and approved supporting procedures, guidelines
and other documents.
Nuclear Emergency Organization (NEO) (Organisation d’urgence nucléaire [OUN])A CNSC body that carries out all CNSC activities needed to effectively respond to a nuclear emergency.
nuclear energy (énergie nucléaire)
Any form of energy released in the course of nuclear fission or nuclear fusion or of any other nuclear
transmutation. (Source: Nuclear Safety and Control Act)
Nuclear Energy Agency (NEA) (Agence pour l’énergie nucléaire [AEN])
A specialized agency within the Organisation for Economic Co-operation and Development. The missionof the NEA is to assist its member countries in maintaining and further developing, through international
cooperation, the scientific, technological and legal bases required for the safe, environmentally friendly
and economical use of nuclear energy for peaceful purposes.

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nuclear energy worker (NEW) (travailleur du secteur nucléaire [TSN])
A person who is required, in the course of the person’s business or occupation in connection with anuclear substance or nuclear facility, to perform duties in such circumstances that there is a reasonableprobability that the person may receive a dose of radiation that is greater than the prescribed limit for thegeneral public. (Source: Nuclear Safety and Control Act)
nuclear facility (installation nucléaire)
Any of the following facilities, namely,(a) a nuclear fission or fusion reactor or subcritical nuclear assembly,(b) a particle accelerator,(c) a uranium or thorium mine or mill,(d) a plant for the processing, reprocessing or separation of an isotope of uranium, thorium or plutonium,(e) a plant for the manufacture of a product from uranium, thorium or plutonium,(f) a plant for the processing or use, in a quantity greater than 1015 Bq per calendar year, of nuclear
substances other than uranium, thorium or plutonium,(g) a facility for the disposal of a nuclear substance generated at another nuclear facility,(h) a vehicle that is equipped with a nuclear reactor, and(i) any other facility that is prescribed for the development, production or use of nuclear energy or the
production, possession or use of a nuclear substance, prescribed equipment or prescribed information,and includes, where applicable, the land on which the facility is located, a building that forms part of, or
equipment used in conjunction with, the facility and any system for the management, storage or disposalof a nuclear substance.
(Source: Nuclear Safety and Control Act)OR
[Any of the following:](a) any nuclear reactor, including a reactor installed on a vessel, vehicle, aircraft or space object for use
as an energy source in order to propel the vessel, vehicle, aircraft or space object or for any otherpurpose, and(b) any plant or conveyance used for the production, storage, processing or transport of nuclear material
or radioactive material(Source:Criminal Code)OR
With respect to safeguards, see facility.
nuclear facility perimeter (périmètre de l’installation nucléaire)
The outer boundary of a geographical area that contains the licensed facility and within which the
management of the licensed facility may directly initiate emergency actions. The nuclear facility
perimeter typically encloses the area within the security fence or other designated property marker.
nuclear loss (consommation)
The loss of nuclear material due to its transformation into other element(s) or isotope(s) as a result of
nuclear reactions. Nuclear loss also includes burnup of nuclear material in a reactor and radioactive decay(for example, plutonium-241).
nuclear material (matières nucléaires)
With respect to safeguards, means plutonium-239, uranium-233, uranium enriched in the isotopes of 235
or 233, uranium containing the mixture of isotopes occurring in nature, uranium depleted in isotope 235
and thorium. The term nuclear material does not apply to uranium or thorium in ore, ore residue or othernaturally occurring materials.

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nuclear medicine room (salle de médecine nucléaire)
Any area or enclosure where nuclear substances are prepared for or administered to a person (via
injection, inhalation or ingestion) for the purpose of diagnosing or treating disease and for human researchstudies (excluding medical diagnostic X-rays or the medical use of sealed sources for brachytherapy or
teletherapy treatments).
nuclear medicine technologist (technologue en médecine nucléaire)
A medical radiation technologist certified by the Canadian Association of Medical Radiation
Technologists. Working in the field of nuclear medicine, this technologist performs various duties. For
example, the technologist prepares and administers radiopharmaceuticals, takes images of different
organs and bodily structures, uses computers to process data and enhance images, analyzes biological
specimens and works closely with all members of the healthcare team.
nuclear poison (poison nucléaire)
See neutron absorber.
nuclear power plant (NPP) (centrale nucléaire)
A nuclear facility consisting of any fission-reactor installation that has been constructed to generate
electricity on a commercial scale. (Source: Nuclear Security Regulations)
Note 1: An NPP may include more than one nuclear reactor.
Note 2: An NPP may also be constructed with the intent to provide heat or steam on a commercial scale.
Note 3: An NPP is a Class IA nuclear facility, as defined in the Class I Nuclear Facilities Regulations.
nuclear production (production nucléaire)
The generation of special fissionable material through the irradiation of fertile material in a reactor.
Nuclear Regulatory Commission (NRC) (Nuclear Regulatory Commission [NRC])
See U.S. Nuclear Regulatory Commission.
Nuclear Safety and Control Act (NSCA) (Loi sur la sûreté et la réglementation nucléaires [LSRN])
An Act of Parliament that came into force on May 31, 2000, replacing the Atomic Energy Control Act.
The NSCA provides the Canadian Nuclear Safety Commission with its regulatory authority.
nuclear security officer (NSO) (agent de sécurité nucléaire [ASN])
A person whose function is to provide security at a high-security site and to whom an authorizationreferred to in subsection 18(2) has been issued. (Source: Nuclear Security Regulations)
nuclear substance (substance nucléaire)
Means:(a) deuterium, thorium, uranium or an element with an atomic number greater than 92;(b) a derivative or compound of deuterium, thorium, uranium or of an element with an atomic number
greater than 92;(c) a radioactive nuclide;(d) a substance that is prescribed as being capable of releasing nuclear energy or as being required for the
production or use of nuclear energy;(e) a radioactive by-product of the development, production or use of nuclear energy; and(f) a radioactive substance or radioactive thing that was used for the development or production, or inconnection with the use, of nuclear energy.
(Source: Nuclear Safety and Control Act)91

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nuclear substance laboratory (laboratoire de substances nucléaires)
A laboratory in which unsealed sources are used. Also called radioisotope laboratory.
Nuclear Suppliers Group (NSG) (Groupe des fournisseurs nucléaire (GFN))
A multilateral export control regime of nuclear supplier countries which seeks to contribute to the nonproliferation of nuclear weapons through the implementation of International Atomic Energy Agency
Guidelines (INFCIRC/254, Communications Received from Certain Member States Regarding Guidelines
for the Export of Nuclear Material, Equipment or Technology [6]) for supply of nuclear and nuclearrelated dual-use items.
nucleus (noyau)
The very dense region at the centre of an atom that consists of protons and neutrons.
nuisance actors (personnes nuisent)
With respect to emergency preparedness, any group of individuals, from the curious to the malevolent,
whose presence outside the protected zone may interfere with emergency response activities.

O
obligations (obligations)
Legally binding commitments regarding nuclear material, non-nuclear material, nuclear equipment andnuclear information (sometimes referred to as “flags”). Obligations arise most commonly from therequirements of government-to-government nuclear cooperation agreements, wherein the parties to theagreements are bound to fulfill those requirements before authorizing the transfer of the obligated items.
observed reliability (fiabilité observée)
A reliability measure that is calculated using actual operating performance.
observer (observateur)
In an emergency exercise, a person who is authorized to witness the exercise but who is not a participant,controller or evaluator.
obsolescence (obsolescence)With respect to structures, systems and components, the process of becoming out of date in comparison
with current knowledge, standards and technology.
OBT (TLCO)
organically bound tritium
occupancy factor (facteur d’occupation)
The fraction of total time during which a radiation field is present at a particular location, for which any
one individual would reasonably be expected to be present at that location. This factor (≤1) is multipliedby the total radiation dose at that location, to derive the maximum personal dose any single person would
be expected to receive.
offsite (hors site)
The facilities and organizations outside the juridical consideration of the licensed facility, including thevarious federal, provincial and municipal organizations that are required to communicate with andrespond to a facility accident in accordance with the facility accident management procedures.

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offsite power (alimentation électrique hors site)
The alternating current (AC) power supplied from the transmission system (grid), to the plant electrical
power distribution systems.
offsite response force (force d’intervention externe)
A local, provincial or federal police service whose members are not located at a nuclear facility.
(Source: Nuclear Security Regulations)OJT (formation en cours d’emploi [FCE] ou formation en milieu de travail)See on-the-job training.
OLC (LCE)
See operational limits and conditions.
one-year dosimetry period (période de dosimétrie d’un an)
The period of one calendar year beginning on January 1 of the year following the year in which theseRegulations come into force, and every period of one calendar year after that period. (Source: Radiation
Protection Regulations)
Note: These Regulations came into force in May 2000; therefore the first dosimetry period began on
January 1, 2001.
onsite (sur le site)
The physical domain of the facility to which a licence is granted.
onsite nuclear response force (force d’intervention nucléaire interne)
Means:(a) a team of nuclear security officers whose members are(i) trained in the use of firearms, authorized to carry firearms in Canada and qualified to use them,and(ii) permanently located at a high-security site; or(b) a local, provincial or federal police service, a Canadian Forces unit or any other force(i) under contract to a licensee,(ii) whose members are trained in the use of firearms, authorized to carry firearms in Canada andqualified to use them, and(iii) whose members are permanently located at a high-security site
(Source: Nuclear Security Regulations)
onsite power (alimentation électrique sur le site)
Power supplied from a nuclear power plant’s alternating current (AC) power systems, direct current (DC)power systems and uninterruptible AC power systems.
on-the-job evaluation (évaluation en cours d’emploi)
Performance demonstration by a trainee of knowledge, skills, safety-related attributes and work practicestandards required to perform a task using the approved procedure and the prescribed standards. The
evaluation is conducted on the job.
on-the-job training (OJT) (formation en cours d’emploi [FCE]ou formation en milieu de travail)The training undertaken in the actual work environment to obtain required job-related knowledge andskills.

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OP&P (LCE)
See operating policies and principles.
open source (source non scellée)
See unsealed source.
operate (faire fonctionner)
Includes, in respect of an exposure device, coupling the drive mechanism to the exposure device,uncoupling the drive mechanism from the exposure device, locking or unlocking the exposure device, andall activities involving the device that take place while the sealed source assembly is not locked inside thedevice in the fully shielded position. (Source: Nuclear Substances and Radiation Devices Regulations)OR
For other devices, equipment or facilities, operate means turning on and using the device, equipment or
facility for its intended purpose and in accordance with the manufacturer’s instructions. Operate includes
minor upkeep as per the operating manual.
operating experience (OPEX) (expérience d’exploitation [OPEX])
Pertinent internal and external information, gained through practical experience, used to learn about andimprove the safety and reliability of nuclear facilities.
operating organization (exploitant)
The responsible organization that operates, or will operate, a facility. This organization may be thelicensee, the applicant or an organization that will operate the facility on behalf of the applicant.
operating performance SCA (DSR Conduite de l’exploitation)
A safety and control area (SCA) that includes an overall review of the conduct of the licensed activities
and the activities that enable effective performance. This SCA is one of the 14 within the CNSC SCA
Framework.
operating policies and principles (OP&P) (lignes de conduite pour l’exploitation [LCE])
The boundaries within which a nuclear power plant must be operated, maintained and modified, to keep
the risk to workers, the public and the environment acceptably low.
operating states (états de fonctionnement)
See operational states.
operation (exploitation)
All activities performed to achieve the purpose for which a nuclear facility was constructed. For example,
at reactor facilities, operation includes maintenance, refuelling, in-service inspection and other associatedactivities.
operational limits and conditions (OLC) (limites et conditions d’exploitation [LCE])
A set of rules setting forth parameter limits and the functional capability and performance levels ofequipment and personnel for safe operation of a nuclear facility. This set of limits and conditions ismonitored by or on behalf of the operator and can be controlled by the operator.
operational mode (mode d’exploitation)
In a reactor facility, a mode of operation that may include start-up, operation at various power levels,
shutting down, shutdown, maintenance, testing and refuelling.

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operational parameters (paramètres d’exploitation)
See plant parameters.
operational states (états de fonctionnement)
Plant states defined under normal operation and anticipated operational occurrences.
operations with fissionable materials (activités comportant des matières fissiles)
Any activity involving the handling, use, processing, movement and storage of fissionable materials
within nuclear facilities and the long-term management of nuclear waste containing fissionable materials.
operator (exploitant)
A person who is designated by a regulation made under section 7 as an operator. (Source: Nuclear
Liability and Compensation Act)OR
The holder of a subsisting licence issued pursuant to the Nuclear Safety and Control Act for the operationof a nuclear installation or, in relation to any nuclear installation for the operation of which there is no
subsisting licence, the recipient of the licence last issued pursuant to the Nuclear Safety and Control Act
for the operation of that nuclear installation.
OR
operator (opérateur)
An industrial device operator.
OR
A person responsible for nuclear material inventory.
OR
See certified exposure device operator.
OR
See reactor operator.
OR
See unit 0 operator.
OPEX (OPEX)
See operating experience.
oral fluid specimen collector (personne chargée du prélèvement des échantillons de sécrétions orales)
A trained person who instructs and assists workers at an oral fluid collection site, receives the specimen
provided by each worker and performs an initial inspection of that specimen, and initiates and completesa custody control form for that specimen.
order (ordre)
One of the regulatory tools the CNSC uses to compel someone to do something in the interests of health,safety, the environment, national security or compliance with Canada’s international obligations. Failure
to comply with an order can lead to further regulatory measures, including prosecution or licensing
actions.
ore (minerai)
A mineral or chemical aggregate containing uranium in a quantity and of a quality that makes mining andextracting the uranium economically viable. (Source: Uranium Mines and Mills Regulations)
Note: Ore may also include thorium.

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organically bound tritium (OBT) (tritium lié aux composés organiques [TLCO])
Tritium that is bound to an organic molecule. For dosimetry purposes, OBT is carbon-bound tritium
formed in living systems through natural biological processes.
orphaned source (source orpheline)
A radioactive source that is found in the public domain, and for which no responsible owner can beestablished, or which is in the possession of a person who cannot be held responsible for the source’s safe
storage or disposal.
other person (autre personne)
With respect to a location where licensed activity is carried out, a person who is present at the location but
does not perform work referred to in the licence.
other worker (autre travailleur)A worker who has not been designated as a nuclear energy worker and is subject to the prescribed dose
limit for the general public.
overburden (morts-terrains)
For uranium mining purposes, generally the material overlying the ore deposit, including rock as well as
soil and other unconsolidated (loose) material, such as glacial deposits, sand and sediment.
overhaul (remise en état)The comprehensive inspection and restoration of a structure, system or component to maintain it in good
operating condition or to restore its ability to function as per design. Overhaul includes such actions as
disassembly, cleaning, lubrication, adjustments, parts inspection or replacement, and testing.
overpack (suremballage)Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)

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

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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)OR
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)
Means:(a) in relation to a licence application, the applicant;(b) in relation to a licence renewal, suspension, amendment, revocation or replacement, the licensee;(c) in relation to a matter being heard by the Commission in the public interest under the Act, and if theseRules do not otherwise set out who the parties are, any person whom the Commission names as party
in the proceeding;(d) in relation to the review by the Commission of an order of an inspector or a designated officer, aperson who is named in or subject to the order;(e) in relation to an appeal made to the Commission under subsection 43(1) of the Act, the appellant;(f) in relation to a rehearing and redetermination under subsection 43(2) of the Act, any of the persons
referred to in that subsection; and(g) 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)
PAS (EAP)
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, mechanicalmovement or supply of power.
passive engineered (nuclear) criticality safety control (contrôle technique passif de sûreté-criticité[nucléaire])
See engineered (nuclear) criticality safety control.
PBD (DEP)
See pressure boundary degradation.
PDR (DDP)
pulsed dose rate97

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penalty (pénalité)
An administrative monetary penalty imposed under this Act for a violation. (Source: Nuclear Safety andControl Act)
PEOC (CPOU)
Provincial Emergency Operations Centre
performance evaluation (évaluation de la performance)
With respect to reliability programs, analysis based on initial objectives and estimates and usually madeonsite, 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 ofoperating 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 areactor 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 ornumber 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.

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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 aworker 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 tomeet specified job performance requirements. The personnel qualification is a formal statement ofcompetence.
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)
PET (TEP)
See positron emission tomography.
PHTS (CCP)
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 andcomponents 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 withthe 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 balancearea 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 theprotection 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, toprevent adversaries from achieving their goal. The physical protection system also applies duringtransport of nuclear substances.

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physical protection system support person (préposé au soutien du système de protection physique)
A person who:(a) carries out the design, implementation, maintenance or repair of a physical protection system at ahigh-security site or conducts training related to one or more of those activities; and(b) 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.
PIE (EIH)
See postulated initiating event.
PIF (FIP)
See potential intake fraction.
pilot course (cours pilote)
A trial of an instructional program before it is implemented in training.
PIV (VSP)
See physical inventory verification.
planned maintenance (entretien planifié)
A form of preventive maintenance consisting of refurbishment or replacement that is scheduled andperformed 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, isof 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 thecurrent 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 aplanned 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 todecommissioning 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 andparts of a facility, including the organizational structure.
plant design envelope (enveloppe de conception de la centrale)
See design envelope.

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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 andprovincial 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 thematerials 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 subsetof 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
Accident conditions➔

Beyond-design-basis accident➔

Operational states

Normaloperation

Anticipatedoperational
occurrence

Design basis

Design-basis
accident

Design extension
conditions

Practically eliminatedconditions➔

No severe fueldegradation

Severe accidents➔

Design extension

Not considered as design
extension➔

Reducing frequency of occurrence ➔point of collection testing (analyse au point de prélèvement)
An immunoassay urine or oral fluid drug screening test that is conducted in the field outside a laboratory
setting and that provides immediate results.
point-kernel technique (technique des noyaux ponctuels)
A technique based on an analysis point source solution where the unattenuated flux at any distance r fromthe 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.

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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 thecosts 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 thecreation 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). Notethat 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 accident (situation post-accidentelle)
A long-term safe stable state that is achieved in the reactor facilities after an accident.
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 ina 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; forcause testing; pre-placement testing; reasonable grounds testing; safety significance.

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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, dependingon 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:(a) the unauthorized removal of Category I, II or III nuclear material; or(b) 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 afunction 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.
PPE (EPI)
personal protective equipment
PPS (SPP or AEP)
See physical protection system or preferred power supply.
PRA (EPS)
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 iscalculated using current reliability data.

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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 fornormal 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 andappropriate 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 theprincipal decommissioning work packages envisioned. As such, the plan forms the strategic basis forestablishing 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 ora 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 theNSCA:(a) a package, special form radioactive material, low dispersible radioactive material, fissile-exceptedradioactive 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 andTransport of Nuclear Substances Regulations, 2015;(b) a radiation device and a sealed source, as defined in section 1 of the Nuclear Substances andRadiation Devices Regulations;(c) Class II prescribed equipment, as defined in section 1 of the Class II Nuclear Facilities andPrescribed Equipment Regulations; and(d) 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, withrespect to the import and export of that equipment. See also controlled nuclear equipment.

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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):(a) 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;(b) the design, production, use, operation or maintenance of a nuclear weapon or nuclear explosive
device;(c) 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(d) 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, withrespect 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 ofparagraph (i) of the definition “nuclear facility” in section 2 of the Nuclear Safety and Control Act(NSCA):(a) 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 thewaste is 1015 Bq or more;(b) a plant for the production of deuterium or deuterium compounds using hydrogen sulphide; and(c) a Class II nuclear facility, as defined in section 1 of the Class II Nuclear Facilities andPrescribed 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 asevere accident.

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preventive maintenance (entretien préventif)
Actions that detect, preclude or mitigate degradation of a functional structure, system or component tosustain 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 thereactor 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 primarycoolant 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 aremaintained.
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 theradionuclides 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 theenvironment and evaluates the resulting effect on public healthThis term is the one commonly used in Canada; however, the terms probabilistic risk assessment andprobabilistic risk analysis are also used sometimes.

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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 tocollect 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 licenseeproduced 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.
project lifecycle (cycle de vie du projet)
Includes all ongoing activities during the main licence granted by the CNSC: preparing the site,
constructing, operating, and decommissioning of a mine project.
projection sheath (tube de guidage)
For exposure devices, a tube for guiding the sealed source assembly from an exposure container to theworking 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.
PROL (PERP)
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.

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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.
prudent management practices (pratiques de gestion prudente)
Include ensuring that sealed sources are secured to prevent illegal use, theft or sabotage, and that aperiodic inventory is carried out to ensure sealed sources are at their designated location and are secure.
PRV (VDV)
primary relief valve
PSA (EPS)
See probabilistic safety assessment.
PSR (BPS)
See periodic safety review.
public disclosure (divulgation publique)
The act of making information available to the public.
PWR (REP)
pressurized water reactor
pyrophoricity (pyrophoricité)
The property of a material or substance that ignites spontaneously when exposed to air or when rubbed or
struck.

Q
QM (GQ)See quality management.
qualification (qualification)
A recognized level of mastery of task performance in a work-related field, which is normally acquired
through successful completion of training. Qualification involves mastery of all the knowledge, skills andsafety-related attributes required for successful task performance on the job.
qualified (qualifié)
With respect to personnel certification, being eligible and meeting the requirements to be a successful
applicant for certification as an RSO.
qualified technician (technicien qualifié)
See breath alcohol technician.
quality management (QM) (gestion de la qualité [GQ])
With respect to nuclear criticality safety, a planned and systematic pattern of all means and actions
designed to provide adequate confidence that items or services meet specified requirements and will
perform satisfactorily in service.

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R (R)See response.
radiation (rayonnement)
The emission by a nuclear substance, the production using a nuclear substance, or the production at anuclear facility of, an atomic or subatomic particle or electromagnetic wave with sufficient energy forionization. (Source: Nuclear Safety and Control Act)
radiation device (appareil à rayonnement)
Means:(a) a device that contains more than the exemption quantity of a nuclear substance and that enables
the nuclear substance to be used for its radiation properties; and(b) a device that contains a radium luminous compound.
(Source: Nuclear Substances and Radiation Devices Regulations)radiation protection SCA (DSR Radioprotection)
A safety and control area (SCA) that covers the implementation of a radiation protection program inaccordance with the Radiation Protection Regulations. The program must ensure that contaminationlevels and radiation doses received by individuals are monitored, controlled and maintained ALARA.
This SCA is one of the 14 within the CNSC SCA Framework.
radiation safety officer (RSO) (responsable de la radioprotection [RRP])
A radiation safety specialist who implements and administers a radiation safety program on a day-to-day
basis. Note: As specified in subsection 15.04 of the Class II Nuclear Facilities and Prescribed Equipment
Regulations, the Commission or a designated officer may certify a person for the position of radiation
safety officer if the person has successfully completed an examination that is recognized by theCommission and, in the opinion of the Commission or designated officer, the person is capable ofperforming the duties of the position.
radiation survey meter (radiamètre)An instrument that is capable of measuring radiation dose rates. (Sources: Class II Nuclear Facilities andPrescribed Equipment Regulations; Nuclear Substances and Radiation Devices Regulations)radiation weighting factor (wR) (facteur de pondération radiologique [wR])
A number by which the absorbed dose in a tissue or organ is multiplied to reflect the relative biologicaleffectiveness (harm) of the radiation in inducing stochastic effects at low doses, the result being theequivalent dose.
radioactive atmosphere (atmosphère radioactive)
See dosimetry types.

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radioactive decay (désintégration radioactive)
The spontaneous transformation of one radioisotope into one or more different isotopes (known as decay
products or daughter products), accompanied by a decrease in radioactivity (compared to the parent
material). This transformation takes place over a defined period of time (known as a half-life), as a resultof electron capture; fission; or the emission of alpha particles, beta particles, or photons (gamma radiationor X-rays) from the nucleus of an unstable atom. Each isotope in the sequence (known as a decay chain)decays to the next until it forms a stable, less energetic end product. In addition, radioactive decay may
refer to gamma-ray and conversion electron emission, which only reduces the excitation energy of thenucleus.
radioactive material (matière radioactive)
A nuclear substance that is a radioactive material, as defined in the IAEA Regulations.
(Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
Note: The IAEA Regulations identify this substance as any material containing radionuclides where boththe activity concentration and the total activity in a consignment exceed the values further specified by the
IAEA Regulations.
OR
For purposes of nuclear security, any material that emits one or more types of ionizing radiation, such asalpha or beta particles, neutrons or gamma rays.
radioactive source (source radioactive)
Radioactive material that is permanently sealed in a capsule or closely bonded in a solid form, and which
is not exempt from regulatory control. This term also means any radioactive material released if theradioactive source is leaking or broken, but does not mean material encapsulated for disposal, or nuclear
material within the nuclear fuel cycles of research and power reactors.
radioactive source teletherapy machine (appareil de téléthérapie à source radioactive)
A teletherapy machine that is designed to deliver doses of radiation produced by a nuclear substance.
(Sources: General Nuclear Safety and Control Regulations; Class II Nuclear Facilities and Prescribed
Equipment Regulations)radioactive waste (déchets radioactifs)
For the purposes of waste management, any material (liquid, gaseous or solid) that contains a radioactive
nuclear substance, as defined in section 2 of the Nuclear Safety and Control Act, and which the owner has
declared to be waste. In addition to containing nuclear substances, radioactive waste may also containnon-radioactive hazardous substances, as defined in section 1 of the General Nuclear Safety and Control
Regulations.
radioactivity (radioactivité)
The spontaneous transformation of an atom’s nucleus by expulsion of particles. Radioactivity can beaccompanied by electromagnetic radiation. Solids, liquids or gases can be radioactive.
radiography camera (caméra de gammagraphie)
See exposure container.
radioiodine (iode radioactif)
A substance containing radioactive iodine in a chemical form that has a metabolic pathway similar toiodide, such as inorganic compounds and metabolic forms of organic iodine that are broken down in aliving organism. Some examples are the radioisotopes iodine-125 and iodine-131.

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radioiodine bioassay (essai biologique visant à détecter l’iode radioactif)
The measurement of the amount of radioiodine in the body, for the purpose of finding out the associatedcommitted effective dose.
radioisotope (radio-isotope)
See isotope.
radioisotope laboratory (laboratoire de radio-isotopes)
See nuclear substance laboratory.
radionuclide (radionucléide)A material with an unstable atomic nucleus that spontaneously decays or disintegrates, producing
radiation. Nuclei are distinguished by their mass and atomic number.
radiosensitivity (radiosensibilité)
The relative susceptibility to damage from radiation for cells, tissues, organs and organisms. Not to be
confused with radiosusceptibility, which is the relative susceptibility to develop genomic instability andcancer.
radon decay product (produit de désintégration du radon)
See radon progeny.
radon progeny (produit de filiation du radon)
The following radioactive decay products of radon-222: bismuth-214, lead-214, polonium-214 andpolonium-218. (Sources: Radiation Protection Regulations; Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: These nuclear substances are emitted when radon gas undergoes radioactive decay. Polonium-218
and polonium-214 emit alpha particles and are responsible for the bulk of the dose to the respiratory tract
resulting from inhaled radon. All four of these short-lived radon progeny have half-lives of less than
30 minutes. Also known as radon decay product.
random testing (test aléatoire de dépistage)
With respect to fitness for duty, a statistically random and unannounced basis for selecting which workers
designated in safety-critical positions will be subject to alcohol and drug testing, so that each worker has
an equal probability of being selected and tested. See also safety-critical position.
Raschig ring (anneau de Raschig)
A small, hollow, borosilicate-glass cylinder having approximately equal length and diameter.
RAW (RAR)
risk achievement worth; see importance measures
RCA (analyse des causes fondamentales)
See root-cause analysis.
RCM (MAF)
See reliability-centred maintenance.
RCS (SRR)
reactor coolant system111

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RDR (RRR)
risk decrease ratio; see importance measures
reactivity (réactivité)
The quantity (keff - 1) / keff, where keff is the effective neutron multiplication factor. The reactivity of a
subcritical assembly is a negative quantity indicating the degree of subcriticality. The reactivity of a
critical assembly is zero.
reactivity addition (addition de réactivité)
A modification of a fissile assembly that results in a positive incremental change of reactivity.
reactor containment (confinement du réacteur)
See containment.
reactor coolant system (système de refroidissement du coeur)
See primary heat transport system.
reactor facility (installation dotée d’un réacteur)
Any fission or fusion reactor, including structures, systems and components:• that are necessary for shutting down the reactor, ensuring that it can be kept in a safe shutdown state• that may contain radioactive material and which cannot be reliably isolated from the reactor• whose failure can lead to a limiting accident for the reactor• that are tightly integrated into the operation of the nuclear facility• that are needed to maintain security and safeguards
reactor operator (opérateur de réacteur)
The person in a reactor facility who is responsible for operating and monitoring the systems of a reactor
unit, in accordance with the licence, policies and procedures. Also called authorized nuclear operator;
control room operator.
reactor state (état du réacteur)See plant state.
reactor trip (arrêt automatique du réacteur)A reduction in reactor power initiated by any of a reactor’s safety circuits. A reactor trip rapidly shuts
down the reactor in response to the detection of certain abnormal and potentially dangerous conditions orby operator decision.
reasonable grounds testing (test de dépistage pour motifs raisonnables)
With respect to fitness for duty, an element of for-cause testing, where workers in safety-critical or safetysensitive positions are required to submit to testing when there is reasonable cause to believe, throughobserved behaviour, physical condition or after receiving credible information, that the individual is unfit
to perform their duties, due to the adverse effects of alcohol or drug use. See also fitness for duty; forcause testing; post-incident testing; pre-placement testing.
re-batching (remise en lots)
With respect to nuclear material accounting, accounting for changes to the physical inventory (such as
chemical and physical form, irradiation status) of an individual batch of nuclear material.

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receptor (récepteur)
Any person or environmental entity that is exposed to radiation, a hazardous substance, or both. A
receptor is usually an organism or a population, but it could also be an abiotic entity such as surface wateror sediment.
recognized educational institution (institution reconnue)
A Canadian educational institution with a federal or provincial charter, or a foreign educational institution
whose diplomas are accepted by a recognized Canadian institution or university.
recognized university (université reconnue)
A Canadian university with a federal or provincial charter, or a foreign university whose degrees are
accepted by a recognized Canadian university.
record (document)
Has the meaning assigned to that word by section 3 of the Access to Information Act. (Source: Nuclear
Safety and Control Act)
Note: The Access to Information Act states that a record means any documentary material, regardless of
medium or form.
redundancy (redondance)
The provision of alternative (identical or diverse) structures, systems and components (SSCs), so that any
one can perform the required function regardless of the state of operation or failure of any other SSC.
reference value (valeur de référence)
See conventionally true value.
refresher training (formation de recyclage)
See continuing training.
region (région)
With respect to site evaluation for a new nuclear facility, a specific area to be studied. The spatial
characteristics of a region will vary for each hazard being studied. For example, the region being
investigated for groundwater effects of a nuclear power plant may be substantially different from theregion being investigated for effects due to atmospheric releases.
registered user (usager inscrit)
A person who has received confirmation under subsection 19(3) from the Commission that their use of a
package has been registered. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
Registrar (registraire)
The Registrar of the Commission. (Sources: Canadian Nuclear Safety Commission Rules of Procedure;
Canadian Nuclear Safety Commission By-laws)
Note: The Canadian Nuclear Safety Commission Rules of Procedure further state that the Registrar is
appointed under section 16 of the NSCA.

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regulation (règlement)
The “operational” part of a law. In Canada, a regulation is made under a specified Act, the means bywhich Parliament makes laws. A regulation commonly deals with matters such as what is meant bycertain terms used in the Act, procedures and processes that must be followed or standards that must be
met in order to comply with the Act. Often referred to as delegated legislation or subordinate legislation, a
regulation is not made by Parliament but by someone to whom Parliament has delegated the authority tomake it. The Commission has the authority under the Nuclear Safety and Control Act (NSCA) to makeregulations, with the approval of the Governor in Council, for matters related to its mandate.
regulatory hold point (point d’arrêt réglementaire)
A commissioning activity that requires approval of the Canadian Nuclear Safety Commission in order forcommissioning to proceed.
regulatory scrutiny (contrôle réglementaire)
A regulator’s enforcement option to focus efforts on specific areas of non-compliance. This scrutiny may
include:• increasing the frequency of inspections or of meetings with the licensee• adding more reporting requirements• broadening the scope of inspections• modifying inspection techniques/strategies (for example, root-cause analysis, augmented inspections)
regulatory undertaking (travail réglementaire)
Outage work required by a code or a standard that is referenced in a licence (mandatory work) or otherwork that was committed by the licensee to the CNSC through formal correspondence (committed work)
including:• periodic inspection program (PIP) inspections in the last outage of a PIP cycle• PIP work that is required to allow the extension of an existing disposition that will expire before thenext planned outage
related experience (expérience pertinente)
For certification purposes, the experience a person has gained in performing duties related to those of theposition being sought.
reliability (fiabilité)
The ability of a structure, system or component to perform, in accordance with its defined specifications,
its required function under given conditions for a defined time period or upon demand.
reliability-centred maintenance (RCM) (entretien axé sur la fiabilité)
A series of orderly steps for identifying system and subsystem functions, functional failures and dominantfailure modes; prioritizing them; and selecting applicable and effective preventive maintenance tasks toaddress the classified failure modes.
reliability monitoring (surveillance de la fiabilité)
Direct monitoring of reliability parameters of a structure, system or component (for example, failure
frequency, downtime due to the maintenance activities, or outage rate).
reliability targets (objectifs de fiabilité)
The reliability goals to be achieved by the plant systems. The purpose of these targets is to compare themwith actual plant performance, in order to identify deviations from expected performance.

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remediation (remise en état)Any measures that may be carried out to reduce the radiation exposure due to contamination of land areas
through actions applied to the contamination itself (the source) or to the exposure pathways to humans.
Note: Often remediation is used to restore land areas to conditions suitable for limited use under
institutional control.
remote control (télécommande)
For exposure devices, a device that enables the sealed source assembly to be moved to and from aworking position by the operator while at a safe distance from the exposure container. Note: The remotecontrol includes the control mechanism and also, where applicable, the control cable, control cable sheathand necessary connections and attachments. Also called control mechanism; cranking mechanism; drive
mechanism.
removal site (site d’extraction)
A place at which uranium is removed from its place of natural deposit by means of surface activities forthe purpose of evaluating a potential ore body. (Source: Uranium Mines and Mills Regulations)repair (réparation)
Any activity that allows a failed or degraded structure, system or component to function as per original
design; repair may be permanent or temporary.
replacement (remplacement)
For reactor facilities, the substitution of a structure, system or component (SSC) with an identical SSC orwith an SSC that has been approved as equivalent through an equivalency process.
representative nuclear criticality accident (accident de criticité nucléaire représentatif)
A postulated nuclear criticality accident that is used to demonstrate compliance with the CNSC criticality
safety requirements on the mitigation of nuclear criticality accident consequences.
requalification training (formation de requalification)
See continuing training.
residual heat (chaleur résiduelle)
The sum of heat originating from radioactive decay, fission in the fuel in the shutdown state, and the heatstored in structures, systems and components.
response (R) (réponse [R])With respect to dosimetry, the result of a dose measurement under defined conditions divided by theconventionally true dose that would be received under those conditions.
OR
See emergency response.
response unit (unité d’intervention)
With respect to nuclear security, a team that comprises members of the onsite nuclear response force at anuclear facility and is assigned to mount an effective intervention there.
responsible designer (concepteur responsable)
An organization to which the design authority has assigned responsibility for the design of specific partsof a nuclear facility.

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responsible health physicist (spécialiste principal en radioprotection)
See senior health physicist.
restricted area (zone à accès restreint)
An area to which public access is controlled in order to protect individuals from exposure to radiation andradioactive materials. Also called controlled area.
retained waste (déchets conservés)With respect to nuclear material accounting, a subset of Group 1A nuclear material that has been
identified as unrecoverable and is stored in the material balance area. This Group 1A nuclear material
may be transferred to retained waste upon approval of CNSC staff. After transfer, the only reporting
requirement is to provide an inventory listing upon request.
RIR (RAR)
risk increase ratio; see importance measuresrisk (risque)
The chance of injury or loss, defined as a measure of the probability and severity of an adverse effect(consequence) to health, property, the environment or other things of value; mathematically, risk is theprobability of occurrence (likelihood) of an event multiplied by its magnitude (severity).
risk achievement worth (RAW) (rapport d’augmentation du risque [RAR])
See importance measures.
risk assessment (évaluation du risque)An assessment of the radiological risks associated with normal operation and potential accidents
involving a nuclear substance or licensed activity. A risk assessment will normally include consequenceassessment and associated probabilities.
risk decrease ratio (RDR) (rapport de réduction du risque [RRR])
See importance measures.
risk increase ratio (RIR) (rapport d’augmentation du risque [RAR])
See importance measures.
risk-informed approach (approche en fonction du risque)An approach to decision making that includes risk insights as one of the factors in determining a course ofaction.
risk reduction worth (RRW) (rapport de réduction du risque [RRR])
See importance measures.
risk-significant radioactive sources (sources radioactives à risque élevé)
Any radionuclide identified as a Category 1 or Category 2 radioactive source in table 1 of annex I of theInternational Atomic Energy Agency’s Code of Conduct on the Safety and Security of Radioactive
Sources [8].
root-cause analysis (RCA) (analyse des causes fondamentales)
An objective, structured, systematic and comprehensive analysis for determining the underlying causes ofa situation or event.

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routine bioassay (essai biologique courant)
Any bioassay that involves collecting and analyzing samples or taking measurements on a body atscheduled intervals, or at predetermined times, during normal operations.
RPPE (EPIR)
radiation personal protective equipment
RRW (RRR)
risk reduction worth; see importance measures
RSDS (FSR)
radiation safety data sheets (associated with the Workplace Hazardous Materials Information System)
RSO (RRP)
See radiation safety officer.

S
SA (SA)satisfactory; see safety performance rating methodology
sabotage (sabotage)
Any deliberate act or omission, directed against a nuclear facility or nuclear substances, that:(a) endangers or is likely to endanger the health and safety of any person; or(b) results or is likely to result in contamination of the environment.
(Source: Nuclear Security Regulations)
SAD (distance depuis l’axe de la source)
source axis distancesafeguarded nuclear material (matières nucléaires visées par les garanties)
Source material and special fissionable material under IAEA Safeguards (Safeguard Agreement between
Canada and the IAEA (INFCIRC/164), Subsidiary Arrangements, and Additional Protocol
INFCIRC/164/Add 1) that have reached the stage of the nuclear fuel cycle, as described in article 34(c),of suitability for fuel fabrication or for isotopic enrichment. Note: Nuclear material at or beyond thisstage is subject to all safeguards procedures specified in the Safeguards Agreement. In Canada, this is also
called Group 1 nuclear material.
safeguards (garanties)
A verification system that is established in accordance with a safeguards agreement. (Sources: General
Nuclear Safety and Control Regulations; Class I Nuclear Facilities Regulations)safeguards agreement (accord relatif aux garanties)
Means(a) the IAEA Agreement and any arrangement between Canada and the IAEA made under thatagreement; and(b) any agreement to which Canada is a party for the establishment in Canada of a verification system inrespect of nuclear substances, prescribed equipment or prescribed information, and any arrangements
made under such an agreement.
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safeguards and non-proliferation SCA (DSR Garanties et non-prolifération)
A safety and control area (SCA) that covers the programs and activities required for the successful
implementation of the obligations arising from the Canada/International Atomic Energy Agency (IAEA)
safeguards agreements, as well as all other measures arising from the Treaty on the Non-Proliferation of
Nuclear Weapons. This SCA is one of the 14 within the CNSC SCA Framework.
safeguards equipment (équipement de garanties)
Equipment that is used in accordance with a safeguards agreement. (Source: General Nuclear Safety andControl Regulations)safe operating envelope (SOE) (paramètres d’exploitation sûre [PES])
The set of limits and conditions within which a nuclear power plant must be operated to ensurecompliance with the safety analysis upon which the reactor operation is licensed and that can bemonitored by or on behalf of the operator and can be controlled by the operator. See also operational
limits and conditions.
safe shutdown state (SSS) (état d’arrêt sûr)A state in which a facility is not operational and the fundamental safety functions can be ensured andmaintained stable for a long time. For nuclear reactors, a safe shutdown state is characterized by reactor
subcriticality and the presence of core cooling. For all facilities, radioactive discharges are within limits,and the integrity of the barriers to releases is maintained. See also guaranteed shutdown state; shutdown
state.
safety analysis (analyse de la sûreté)
A systematic evaluation of the potential hazards that is associated with the conduct of a proposed activity
or facility and that considers the effectiveness of preventive measures and strategies in reducing theeffects of such hazards.
OR
With respect to deterministic safety analysis, analysis by means of appropriate analytical tools that
confirms the design basis for the items important to safety and ensures that the overall nuclear facility
design is capable of meeting specified acceptance criteria.
safety analysis program (programme d’analyse de la sûreté)
Activities to plan, execute, verify and document safety analyses; to identify and act upon research andexperience; to train analysts; and to preserve knowledge. The safety analysis program includes interfaces
with other programs to ensure that a safety analysis.
safety analysis SCA (DSR Analyse de la sûreté)
A safety and control area (SCA) that covers maintenance of the safety analysis that supports the overall
safety case for the facility. Safety analysis is a systematic evaluation of the potential hazards associatedwith the conduct of a proposed activity or facility and considers the effectiveness of preventive measuresand strategies in reducing the effects of such hazards. This SCA is one of the 14 within the CNSC SCA
Framework.
safety and control area (SCA) (domaine de sûreté et de réglementation [DSR])
A technical topic used by the CNSC to assess, review, verify and report on regulatory requirements andperformance across all regulated facilities and activities. The SCAs cover:• management system• human performance management• operating performance118

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REGDOC-3.6, Glossary of CNSC Terminology

safety analysis
physical design
fitness for service
radiation protection
conventional health and safety
environmental protection
emergency management and fire protectionwaste management
securitysafeguards and non-proliferation
packaging and transport

safety assessment (évaluation de la sûreté)
An assessment of all aspects relevant to safety of the siting, design, construction, commissioning,
operation or decommissioning of a nuclear facility.
safety case (dossier de sûreté)
An integrated collection of arguments and evidence to demonstrate the safety of a facility and the meetingof all applicable regulatory requirements. A safety case will normally include a safety assessment, but
could also typically include information (such as supporting evidence and reasoning) on the robustness
and reliability of the safety assessment and the assumptions made therein.
safety-critical position (poste essentiel sur le plan de la sûreté)With respect to fitness for duty, a position certified or authorized by the CNSC that requires workers tomake decisions and take actions that have a direct and immediate impact on nuclear safety and security ofa high-security site.
safety culture (culture de sûreté)
The characteristics of a work environment, such as values, rules and common understandings, that
influence worker perceptions and attitudes about the importance that the organization places on safety.
See also security culture.
safety culture assessment (évaluation de la culture de sûreté)
A periodic evaluation of safety culture using a defined framework and method for data collection,
analysis, interpretation and reporting.
safety function (fonction de sûreté)
A specific purpose that a structure, system or component must accomplish for safety, including thosefunctions necessary to prevent accident conditions and to mitigate their consequences.
safety goal (objectif de sûreté)
The objective of protecting reactor facility staff, the public and the environment from harm, by
establishing and maintaining effective defences against the release of radiological hazards. For example, anuclear power plant’s probabilistic safety goals can be expressed in terms of frequency of severe coredamage or of radionuclide releases.

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safety group (groupe de sûreté)
The set of structures, systems and components designated to perform all actions required for a particular
postulated initiating event, and to ensure that the specified limits for anticipated operational occurrencesand design-basis accidents are not exceeded. The safety group may include certain safety and safety
support systems and any interacting process system.
safety improvements (améliorations de la sûreté)
Measures taken that result in more effective implementation of the safety objectives of a nuclear power
plant.
safety indicator (indicateur de sûreté)
A quantity used in assessments to measure the performance of provisions for protection and safety. Safety
indicators can illustrate calculations of dose or risk quantities used to show the possible magnitude ofdoses or risks for comparison with criteria, or of other quantities (such as concentrations or fluxes ofradionuclides or hazardous substances) that are considered to more reliably indicate impact and which canbe compared with protective limits set by legislation or regulation.
safety limits (limites de sûreté)
Limits on operational parameters within which a nuclear facility has been shown to be safe.
safety margin (marge de sûreté)
A margin to the value of a safety variable for a barrier or system at which damage or loss would occur.
Safety margins are considered for those systems and barriers whose failure could contribute toradiological releases.
safety performance indicator (SPI) (indicateur de rendement en matière de sûreté)
Data that is sensitive to and/or signals changes in the safety performance of systems or programs thatmaintain the licensing basis of a nuclear facility.

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safety performance rating methodology (méthode d’attribution des cotes de rendement en matière desûreté)The CNSC’s methodology for rating licensees’ safety performance. This methodology relies on multiple
sources of input derived primarily from CNSC staff findings. These findings are based on regulatory
activities such as inspections, compliance assessment, field rounds, and follow-ups on licensee progresson enforcement actions.
The CNSC applies rating levels as follows:
Satisfactory (SA): The licensee meets all of the following criteria:• Performance meets CNSC staff expectations.
• Licensee non-compliances or performance issues, if any, are not risk-significant.
• Any non-compliances or performance issues have been, or are being, adequately corrected.
Below expectations (BE): One or more of the following criteria apply:• Performance does not meet CNSC staff expectations.
• The licensee has risk-significant non-compliance(s) or performance issue(s).
• Non-compliances or performance issues are not being adequately corrected.
Unacceptable (UA): One or both of the following criteria apply:• The risk associated with a non-compliance or performance issue is unreasonable.
• At least one significant non-compliance or performance issue exists with no associated corrective
action.
The rating levels above replace the following:• Fully satisfactory (FS): Safety and control measures implemented by the licensee are highly
effective. In addition, compliance with regulatory requirements is fully satisfactory and compliancewithin the safety and control area (SCA) or specific area exceeds requirements and CNSC
expectations. Overall, compliance is stable or improving, and any problems or issues that arise arepromptly addressed.
• Satisfactory (SA): Safety and control measures implemented by the licensee are sufficiently
effective. In addition, compliance with regulatory requirements is satisfactory. Compliance within the
SCA or specific area meets requirements and CNSC expectations. Any deviation is minor, and any
issues are considered to pose a low risk to the achievement of regulatory objectives and CNSC
expectations. Appropriate improvements are planned.
• Below expectations (BE): Safety and control measures implemented by the licensee are marginallyineffective. In addition, compliance with regulatory requirements falls below expectations.
Compliance within the SCA deviates from requirements or CNSC expectations to the extent that there
is a moderate risk of ultimate failure to comply. Improvements are required to address identified
weaknesses. The licensee is taking appropriate corrective action.
• Unacceptable (UA): Safety and control measures implemented by the licensee are significantly
ineffective. In addition, compliance with regulatory requirements is unacceptable and is seriously
compromised. Compliance within the SCA is significantly below requirements or CNSC
expectations, or there is evidence of overall non-compliance. Without corrective action, there is ahigh probability that the deficiencies will lead to unreasonable risk. Issues are not being addressed
effectively, no appropriate corrective measures have been taken, and no alternative plan of action has
been provided. Immediate action is required.
safety-related attributes (attributs liés à la sûreté)Observable attributes of safety that reflect an organization’s safety-related values and behaviours thateach worker is expected to exhibit consistently on the job.

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safety-related systems (SRS) (systèmes liés à la sûreté [SRS])As defined in the CSA Group publication CSA-N285.0-08, General requirements for pressure-retaining
systems and components in CANDU nuclear power plants [9]:those systems and their related components and supports that, by failing to perform in accordancewith the design intent, have the potential to impact the radiological safety of the public or nuclear
power plant personnel. Those systems and their components involve• the regulation (including controlled startup and shutdown) and cooling of the reactor core undernormal conditions (including all normal operating and shutdown conditions)• the regulation, shutdown and cooling of the reactor core under anticipated transient conditions
and accident conditions, and the maintenance of the reactor core in a safe shutdown state for an
extended period following such conditions• limiting the release of radioactive material and the exposure of plant personnel and/or the public
to meet the criteria established by the licensing authority with respect to radiation exposure
during and following normal, anticipated transient conditions and accident conditions
Notes:
1) The term “safety-related system” covers a broad range of systems, from those having very
important safety functions to those with a less direct effect on safety. The larger the potential
radiological safety effect due to system failure, the stronger the “safety-related” connotation.
2) “Safety-related” also applies to certain activities associated with the design, manufacture,
construction, commissioning, and operation of safety-related systems and to other activities thatcan similarly affect the radiological safety of the public or plant personnel, such as environmental
and effluent monitoring, radiation protection and dosimetry, and radioactive material handling(including waste management). The larger the potential radiological safety effect associated withthe performance of the activity, the stronger the “safety-related” connotation.
3) Certain failures of other systems can adversely affect a safety-related system (e.g., throughflooding or mechanical damage).
See also systems important to safety.
safety-sensitive position (poste important sur le plan de la sûreté)
A position that has a role in the operation of a high-security site, where impaired performance could resultin a significant incident affecting the environment, the public, the health and safety of workers and othersat the site, or the safety and security of the facility. This definition applies to all workers who are
regularly required to rotate through or regularly relieve others in safety-sensitive positions. Those who
directly supervise working-level positions, or who may perform the same duties or exercise the same
responsibilities as safety-sensitive positions, are deemed to hold safety-sensitive positions. See also highsecurity site.
safety significance (importance pour la sûreté)
The significance of a situation, event or issue with respect to the impact on meeting the nuclear safety
objectives as defined by the IAEA in document SF-1, Fundamental Safety Principles [10]. In general, asituation, event or issue has safety significance if it denotes a deviation from the safety case accepted in
the licence, in a direction detrimental to safety, such as but not limited to:• reducing margins to (or exceeding) the accepted limits• increasing risk to the health, safety and security of persons and the environment• impairing (by various degrees) the safety systems or the safety functions for accident mitigation• reducing defence in depth• causing radioactive releases and spills of hazardous substances and/or injuries to workers or the
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safety support system (système de soutien en matière de sûreté)
A system designed to support the operation of one or more safety systems.
safety system (système de sûreté)
A system provided to ensure the safe shutdown of a nuclear reactor or the residual heat removal from thecore, or to limit the consequences of anticipated operational occurrences and design-basis accidents.
safety system setting (réglage des systèmes de sûreté)
The setpoint for a parameter for which a safety system is automatically actuated in the event of
anticipated operational occurrences or accident conditions, in order to prevent one or more safety limits
from being exceeded.
SAM (GAG)
See severe accident management (SAM) program.
SAMG (LDGAG)
severe accident management guidelines; see severe accident management (SAM) program
SAT (ASF)
See systematic approach to training.
satisfactory (SA) (satisfaisant [SA])See safety performance rating methodology.
SBO (PET)
See station blackout.
SCA (DSR)
See safety and control area.
scattered radiation (rayonnement diffusé)
See scatter radiation.
scatter radiation (rayonnement diffusé)
Radiation that, during passage through a substance, has been changed in direction. It may also have been
modified by a decrease in energy. Also called scattered radiation.
SCDF (FDGC)
severe core damage frequency
SCO (SCO)
Has the meaning assigned by the definition “surface contaminated object (SCO)” in the IAEA
Regulations. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015)
scoping assessment (évaluation d’établissement de la portée)An assessment that uses simplified mathematical models to quickly estimate the likely results that will be
predicted by more detailed assessment models. A scoping assessment can also be used to assess at a highlevel whether the model sensitivity to changes in input values is realistic.
SCR (SCA)
See secondary control room.

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screening (thyroid) (dépistage [thyroïde])See thyroid screening.
SD (arrêt)shutdown
SDCS (CRA)
shutdown cooling systemsealed source (source scellée)
A radioactive nuclear substance in a sealed capsule or in a cover to which the substance is bonded, where
the capsule or cover is strong enough to prevent contact with or the dispersion of the substance under theconditions for which the capsule or cover is designed. (Sources: Class I Nuclear Facilities Regulations;Class II Nuclear Facilities and Prescribed Equipment Regulations; Nuclear Substances and Radiation
Devices Regulations)sealed source assembly (assemblage de source scellée)
Means a sealed source that is designed to be used in an exposure device, and includes the components thatare permanently attached to the sealed source. (Source: Nuclear Substances and Radiation Devices
Regulations)secondary control room (SCR) (salle de commande auxiliaire (SCA))
A room where operations personnel can monitor the safety of a reactor facility and execute basic safetyfunctions to maintain or place the reactor facility in a safe state following any incident that renders themain control room unavailable.
secondary side (côté secondaire)
The system that transports heat from the primary heat transport system to the ultimate heat sink. See also
primary side.
secondary trip parameter (paramètre de déclenchement secondaire)
See primary and backup (secondary) trip parameter.
secured position (position de blocage)
The condition of an exposure container and sealed source assembly when the sealed source is fully
shielded and its movement is restricted within the exposure container. Note: In the secured position, theexposure container need not be locked.
security culture (culture de sécurité)
The characteristics of a work environment, such as the values, rules and common understandings, that
influence workers’ perceptions and attitudes about the importance that the organization places on security.
Note: Security culture is an element of safety culture. See also safety culture.
security interview (entrevue de sécurité)
An interview conducted by a qualified investigator representing a licensee, in which information iscollected to confirm or deny adverse information.
security monitoring room (SMR) (local de surveillance)
A security monitoring room referred to in section 15. (Source: Nuclear Security Regulations)
Note: Section 15 explains that this room comprises video surveillance and recording devices for security
purposes.

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security SCA (DSR Sécurité)
A safety and control area (SCA) that covers the programs required to implement and support the security
requirements stipulated in the regulations, the licence, orders, or expectations for the facility or activity.
This SCA is one of the 14 within the CNSC SCA Framework.
seiche (seiche)
An oscillation of an enclosed or semi-enclosed body of water in response to an atmospheric,oceanographic or seismic disturbing force. In the Great Lakes area, a seiche could mean any sudden risein the water of a harbor or a lake, whether or not it is oscillatory.
senior health physicist (SHP) (spécialiste principal en radioprotection)
The person in a nuclear facility who is responsible for interpreting the regulations, policies andprocedures that apply to radiation protection and for providing procedure-related approvals whererequired. Also called authorized health physicist; responsible health physicist.
sensitivity analysis (analyse de sensibilité)
In a deterministic safety analysis, a quantitative examination of how the behaviour of a system varies
with change (usually in the values of the governing parameters). In a probabilistic safety assessment, theprocess of assessing the impact that a variation in the probability of an event or a change in a modellingassumption would have on the probabilistic safety assessment results.
serious illness or injury (maladie ou blessure grave)With respect to reporting requirements, an injury or illness incurred, or possibly incurred, as a result of
the licensed activity. This term includes an injury or illness resulting in lost time or lost days beyond thedate of injury and is any of the following conditions:• requires hospitalization• places life in jeopardy• produces unconsciousness• results in substantial loss of blood• involves the fracture of a leg or arm, but not a finger or toe• involves the amputation of a leg, arm, hand, or foot, but not a finger or toe• consists of burns to a major portion of the body
• causes the loss of sight in an eye• causes paralysis• causes permanent hearing impairment
Note: “Possibly incurred” refers to the cause of the injury and not the potential for injury. A death isclassified as a fatality, not as a serious injury.
serious process failure (défaillance grave de système fonctionnel)
With respect to reporting requirements for CANDU nuclear power plants (NPPs), a failure of a process
structure, system or component that leads to a systematic fuel failure or a significant release from the NPPor that could lead, in the absence of action by any special safety system, to a systematic fuel failure or asignificant release from the NPP.
service life (durée de vie)
The period from initial operation to final withdrawal from service of a structure, system or component.

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servicing (entretien)
In respect of radiation devices, means any maintenance of a device, including installation, repair or
dismantling, other than maintenance that(a) constitutes routine operating procedures as indicated in the manufacturer’s operating manual for thedevice; or(b) is authorized in the licence issued in respect of the possession or use of the device.
(Source: Nuclear Substances and Radiation Devices Regulations)OR
In respect of Class II prescribed equipment, means any maintenance of the equipment, including
installation, repair or dismantling, other than any installation, repair or dismantling that constitutes routine
operating procedures(a) as indicated in the manufacturer’s operating manual for the equipment; or(b) as authorized in the licence issued in respect of the possession or use of the equipment.
(Source: Class II Nuclear Facilities and Prescribed Equipment Regulations)
Note: Sealed source installation or replacement, as well as any repair that could expose the sealed source,
reduce the shielding around the sealed source, or affect the drive control for radiotherapy, is considered asservicing.
servicing, installation and dismantling of devices containing radioisotopes (entretien, installation etdémontage d’appareils contenant des radio-isotopes)
The possession of radiation devices for the purpose of servicing, installation or dismantling. The term isused as a licence use type.
setback (baisse contrôlée de puissance [BCP])
With respect to CANDU nuclear power plants, a system designed to automatically reduce reactor power
at a slow rate if a problem occurs. The setback system is part of the reactor-regulating system.
severe accident (accident grave)
An accident more severe than a design-basis accident and involving severe fuel degradation in the reactor
core or irradiated fuel storage.
severe accident management guidelines (SAMG) (lignes directrices pour la gestion des accidents
graves [LDGAG])
See severe accident management (SAM) program.
severe accident management (SAM) program (programme de gestion des accidents graves [GAG])
A program that establishes both of the following:• the actions to be taken to prevent severe damage to the reactor core, to mitigate the consequences of
the core damage (should it occur), and to achieve a safe, stable state of the reactor over the long term
• the preparatory measures necessary for implementation of such actions
SGECS (SRUGV)
steam generator emergency cooling systemshift manager (SM) (gestionnaire de quart [GQ])
See plant shift supervisor.
shift supervisor (SS) (chef de quart [CQ])
See plant shift supervisor.

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shift turnover (changement de quart de travail)Transfer of information and responsibilities between individuals or work units, one of which is relieving
the other. Shift turnover activities may include, but are not limited to, discussions of the status of plant
equipment, and the status of ongoing activities, such as extended tests of safety systems and components.
shipper/receiver difference (écart entre expéditeur et destinataire)With respect to nuclear material accounting, the difference between the quantities of nuclear material in abatch, as stated by the shipping material balance area (MBA) and as measured at the receiving MBA.
SHP (spécialiste principal en radioprotection)
See senior health physicist.
shutdown state (état d’arrêt)A subcritical reactor state with a defined margin to prevent a return to criticality without external actions.
See also guaranteed shutdown state; safe shutdown state.
shutoff rod (SOR) (barre d’arrêt [BA])One of a set of neutron-absorbing rods that are inserted into a reactor core when needed to stop (shut offor shut down) the nuclear reactor.
shutter (obturateur)
A system inside a radiation device, between the shielded and unshielded position of the sealed source, that
may be operated manually, electrically or pneumatically.
shy bladder (vessie timide)
The inability to provide a urine sample as a result of a physiological or psychological medical condition.
shy lung (insuffisance pulmonaire)
The inability to provide a sufficient amount or volume of breath to permit a valid alcohol test as a resultof a physiological or psychological medical condition.
SI (SI)
International System of Units (Système international d’unités)significant change (changement important)
In the context of certification of radiation devices or Class II prescribed equipment, a change in theequipment’s characteristics, principles of operation and specifications that could reasonably be expected
to affect the safety or effectiveness of the equipment or the safety of the facility in which it is operated,such as:• a change in the intended use of the device, including any new or extended use (teletherapy machineused as an irradiator)• a change or upgrade of software that allows the machine to work in a different mode or energy leveloutside of the original certification (for example, intensity-modulated radiation therapy (IMRT),
flattening filter free, higher dose rates)• a retrofit for a new head or collimator that would allow a different mode of operation producing
higher leakage rates• an increase of activity of the sources• a change in the model name or machine configuration such that it does not correspond with thecertificate, or significant changes to device labelling – it is important for the machine to be
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sievert (Sv) (sievert [Sv])
The International System of Units (SI) unit of equivalent dose and effective dose, equal to
1 joule/kilogram.
significant release (rejet important)A release of radioactive material that results in an effective dose, received by or committed to a typicalmember of the critical group, in excess of 0.5 millisievert.
signing authority (signataire autorisé)
A person designated by the applicant authority to act on behalf of the applicant in communications with
the CNSC.
simple administrative (nuclear) criticality safety control (contrôle administratif simple desûreté-criticité [nucléaire])
See administrative (nuclear) criticality safety control.
simulator (simulateur)See full scope simulator.
single failure (défaillance unique)
A failure that results in the loss of capability of a component to perform its intended function(s), and any
consequential failure(s) resulting from that single failure.
single-failure criterion (critère de défaillance unique)
The criterion used to determine whether a system is capable of performing its function as per design in thepresence of a single failure.
SIS (SIS)
See systems important to safety.
site (emplacement)
With respect to nuclear facilities, the area where one or more nuclear facilities and all associated support
structures and systems are located. See also exclusion zone.
ORsite (site)
With respect to safeguards, an area delimited by Canada in the relevant design information for a facility,
including a closed-down facility, and in the relevant information on a location outside facilities where
nuclear material is customarily used, including a closed-down location outside facilities where nuclear
material was customarily used. The site is limited to locations with hot cells or where activities related toconversion, enrichment, fuel fabrication or reprocessing were carried out. Note: The site includes all
installations, co-located with the facility or location, for the provision or use of essential services,
including: hot cells for processing irradiated materials not containing nuclear material; installations forthe treatment, storage and disposal of waste; and buildings associated with specified activities identified
by Canada under article 2.a(iv) of the Protocol Additional to the Agreement Between Canada and theInternational Atomic Energy Agency for the Application of Safeguards in Connection with the Treaty on
the Non-Proliferation of Nuclear Weapons [11].
site characterization (caractérisation du site)
The distinguishing characteristics, qualities, physical features and environment of the piece of land on
which a nuclear facility or activity is located.

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site evaluation (évaluation de l’emplacement)
The processes and methodologies used to determine whether the characteristics of a site and thesurrounding region are appropriate for the construction, operation and future decommissioning andabandonment of a nuclear facility regulated under the Nuclear Safety and Control Act.
site personnel (personnel sur le site)
All persons working on the site of a nuclear facility, either permanently or temporarily.
site preparation (préparation de l’emplacement)
The act of establishing basic infrastructure to support the future construction and operation of a nuclear
facility regulated under the Nuclear Safety and Control Act.
siting (choix de l’emplacement)
The process of selecting a suitable site for a facility, including appropriate assessment and definition of
the related design bases.
situation (situation)
Conditions, circumstances or configurations that occur, are discovered or that may lead to an event. Thisdefinition applies to event reporting.
skill (compétence)
A mental and/or physical activity that requires a measurable degree of proficiency. The terms “skill” and“ability” are often used interchangeably.
skin (peau)
The layer of cells within the skin that are 7 mg/cm2 below the surface. (Source: Radiation Protection
Regulations)slapdown (impact secondaire)
The secondary impact resulting from a package initially impacting on a corner or an edge.
sleep debt (manque de sommeil)
The difference between the amount of sleep an individual needs and the amount of sleep that theindividual actually obtains.
SM (GQ)
shift manager; see plant shift supervisor
small modular reactor (SMR)
See reactor facility.
small reactor (petit réacteur)See reactor facility.
smart buyer (acheteur éclairé)
An organization that has a clear understanding and knowledge of the product or service being supplied. In
the context of nuclear safety, the organization knows what is required, fully understands the need for a
vendor’s services, specifies requirements, supervises the work and technically reviews the output before,
during and after implementation.

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SMR (version de maintenance systématique [VMS] or local de surveillance or petit réacteur modulaire[PRM])
scheduled maintenance releaseOR
See security monitoring room.
ORsmall modular reactor; see reactor facility
SNF (combustible nucléaire épuisé)
spent nuclear fuel; see used nuclear fuelSOE (PES)
See safe operating envelope.
soluble neutron absorber (absorbeur de neutrons soluble)
Any neutron absorber easily dispersed in liquid, solution or suspension, used:• specifically to reduce the reactivity of a system and for which reactivity credit is taken in the nuclear
criticality safety evaluation of the systemor• to compensate for excess reactivity in the reactor core during operation or when the reactor is shut
down
solution (solution)
With respect to nuclear criticality safety, liquid containing dissolved material or a suspension of thatmaterial in the liquid. This includes aqueous (water-based) solutions but excludes those where thehydrogen is replaced by either deuterium or tritium.
SOR (BA)See shutoff rod.
somatic effect (effet somatique)A radiation-induced health effect that occurs in the exposed person.
source changer (changeur de source)
An apparatus used to store, transport and exchange sealed source assemblies for use in exposure devices.
source data (données de base)With respect to safeguards, those data, recorded during measurement or calibration or used to derive
empirical relationships, that identify nuclear material and provide batch data. Source data may include,for example, weight of compounds, conversion factors to determine weight of element, specific gravity,
element concentration, isotopic ratios, the relationship between volume and manometer readings, and therelationship between plutonium produced and power generated. See also batch data.
source holder (porte-source)
For exposure devices, a holder, or attachment device, by means of which a sealed source or simulated
source can be directly included in the exposure container or fitted at the end of the control cable.
Note: A source holder may be either an integral part of the sealed source assembly or a part that can bedismantled for replacement of the sealed source.

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source material (matière brute)
The following source materials in any form, including ore, concentrate, compound, metal or alloy, orincorporated in any substance, other than medicinals, and in which the concentration of source material isgreater than 0.05 weight %:(a) uranium that contains the mixture of isotopes that occurs in nature;(b) uranium that is depleted in the isotope 235; and(c) thorium.
Note: [The list above] does not include:(a) source material occurring as contaminants in laundry, packaging, shielding or equipment; or(b) depleted uranium used as shielding for Class II prescribed equipment, within the meaning of section 1of the Class II Nuclear Facilities and Prescribed Equipment Regulations, for radiation devices or fortransport packaging.
(Source: Nuclear Non-proliferation Import and Export Control Regulations (Schedule A))
Note: Ore concentrate is considered to be source material. With respect to nuclear material accounting,the term “source material” is not interpreted as applying to ore or ore residue.
source stop (tête d’exposition)
See exposure head.
source term (terme source)
The amount and isotopic composition of material released (or postulated to be released) from a nuclear
facility.
sparging (barbotage)
The act of flowing air, gas or steam through liquid in a vessel.
special bioassay (essai biologique spécial)
See non-routine bioassay.
special fissionable material (produits fissiles spéciaux)[A]s follows:(a) plutonium and all isotopes, alloys and compounds and any material that contains any of thesesubstances; and(b) uranium-233, uranium enriched in the isotopes 235 or 233 and all alloys and compounds and any
material that contains any of these substances.
Note: [The list above] does not include(a) special fissionable material occurring as contaminants in laundry, packaging, shielding or equipment;(b) special fissionable material used as a sensing component in instruments in quantities of four effective
grams or less; or(c) plutonium-238 that is contained in heart pacemakers.
(Source: Nuclear Non-proliferation Import and Export Control Regulations (Schedule A))
Note: With respect to nuclear material accounting, special fissionable material includes Group 1 nuclear
material that contains plutonium-239, uranium-233, uranium enriched in the isotopes 235 or 233, and any
material that contains any of the foregoing. Special fissionable material does not include source material.
special form radioactive material (matière radioactive sous forme spéciale)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
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Note: This material takes the form of an indispersible solid radioactive material or a sealed capsulecontaining radioactive material that meets the requirements for special form radioactive material, as
specified in the IAEA Regulations and for which a certificate of approval from a competent authority has
been issued.
special safety system (système spécial de sûreté)With respect to CANDU nuclear power plants, one of the following systems: shutdown system no. 1,
shutdown system no. 2, the containment system or the emergency core cooling system.
special waste rock (stériles spéciaux)
See mineralized waste rock.
specialist review (examen spécialisé)
See technical assessment.
specific activity (activité spécifique)
The activity per unit mass. (Source: Nuclear Substances and Radiation Devices Regulations)OR
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
spent fuel (combustible épuisé)
See used nuclear fuel.
spent fuel bay (piscine de stockage du combustible usé)
See wet storage bay.
spent nuclear fuel (SNF) (combustible nucléaire épuisé)
See used nuclear fuel.
SPI (indicateur de rendement en matière de sûreté)
See safety performance indicator.
SRS (SRS)
See safety-related systems.
SS (chef de quart)
shift supervisor; see plant shift supervisor
SSC (SSC)
See structures, systems and components.
SSCs important to safety (SSC importants pour la sûreté)
See systems important to safety.
SSD (distance source-peau [DSP])
source skin distance
SSS (état d’arrêt sûr)See safe shutdown state.

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SStrA (ERMCE)
site selection threat and risk assessment
stakeholder (partie intéressée)Any person or group that has an interest in, is affected by, or has an effect on an environment in which alicensed activity occurs, or has a role in decisions made pertaining to that environment. Some examples
are First Nations; licensees and their sector associations; other federal, provincial, territorial, or municipal
governments or agencies; and the public and commercial sectors dependent on the environment underconsideration. The public may include non-government organizations, community groups, and concerned
individuals. Commercial sectors may include commercial fishing, forestry or trapping.
OR
In an emergency, individuals and organizations with whom the CNSC has direct or indirect relationships,
including all CNSC officers and employees, CNSC-authorized representatives and agents, licensees,
special interest groups, non-governmental organizations, other government departments and agencies(including international organizations), the media and the public.
standard source (source-étalon)
A radioactive source characterized for the activity of radionuclides by the National Research Council of
Canada, or another national standardizing laboratory for radioactivity measurements, and issued with acertificate that gives the results of the characterization.
standby safety-related system (système de sûreté en attente)
As specified by a licensee, those poised systems that provide for the ultimate reactor cooling following
design-basis events (such as emergency power supply and emergency water supply).
starting point of safeguards (point de départ des garanties)
One of two conditions that invoke IAEA safeguards under the Canada/IAEA Safeguards Agreement:• when any nuclear material of a composition and purity suitable for fuel fabrication or for isotopic
enrichment leaves the plant or the process stage in which it has been produced• when such nuclear material, or any other nuclear material produced at a later stage in the nuclear fuelcycle, is imported into Canada
Note: The IAEA safeguards in the agreement do not apply to material in mining or ore processing
activities.
station blackout (SBO) (panne d’électricité totale de la centrale [PETC])
A complete loss of alternating current (AC) power from offsite and onsite main generator, standby andemergency power sources. Note that a station blackout does not include failure of uninterruptible AC
power supplies and direct current power supplies. It also does not include failure of alternate AC power.
Also called extended loss of AC power event.
steam generator (générateur de vapeur)
A heat exchanger that transfers heat from primary coolant in order to boil water. Also called boiler.
Note: The water boils, producing steam to drive a turbine. The steam generator tubes separate the reactor
coolant from the rest of the power-generating system.
stepback (recul rapide de puissance [RRP])
With respect to CANDU nuclear power plants, a system designed to automatically reduce reactor power
at a fast rate if a problem occurs. The stepback system is part of the reactor-regulating system.

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stochastic effect (effet stochastique)A radiation-induced health effect, the probability of occurrence of which is greater for a higher radiationdose and the severity of which (if it occurs) is independent of dose. Note: Stochastic effects may besomatic effects or hereditary effects, and generally occur without a threshold level of dose. Examples
include cancer and leukemia.
storage (stockage)
With respect to nuclear substances and radiation devices, possession for storage only.
storage array (réseau de stockage)
With respect to nuclear criticality safety, a regular arrangement of storage cells.
storage bay (piscine de stockage)
See wet storage bay.
storage cell (cellule de stockage)
With respect to nuclear criticality safety, a volume having defined boundaries within which a storage unit
is positioned.
storage pool (piscine de stockage)
See wet storage bay.
storage unit (unité de stockage)
With respect to nuclear criticality safety, a mass of fissile material considered as an entity. The material
may be of any shape, and a unit may consist of separate pieces.
storage with surveillance (stockage sous surveillance)
A planned stage during a decommissioning program in which the remaining contaminated materials,
equipment and site(s) are placed under controlled surveillance for a specified period of time.
Note: Licensing control by the CNSC remains in effect during such periods.
storm surge (vague de tempête)An abnormal rise in water level accompanying a hurricane or other intense storm.
stratum (strate)
With respect to nuclear material accounting, a grouping of items and/or batches having similar physicaland chemical characteristics. For example, items may be grouped according to isotopic composition inorder to facilitate statistical sampling.
stressor (facteur de stress)
An agent or stimulus stemming from pre-service and service conditions that can produce immediate or
gradual aging degradation of a structure, system or component. Some examples are heat, steam,chemicals, radiation, and electrical cycling.
structures, systems and components (SSCs) (structures, systèmes et composants [SSC])
A general term encompassing all of the elements of a facility or activity that contribute to protection andsafety. Structures are the passive elements: buildings, vessels, shielding, etc. A system comprises several
components, assembled in such a way as to perform a specific (active) function. A component is adiscrete element of a system. Some examples are wires, transistors, integrated circuits, motors, relays,solenoids, pipes, fittings, pumps, tanks and valves.

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structures, systems and components important to safety (SSC importants pour la sûreté)
See systems important to safety.
S-tube (tube en S)
See exposure device source path.
subcritical limit (limite de sous-criticité)
The limiting value assigned to a controlled parameter that results in a subcritical system under specified
conditions. The subcritical limit allows for uncertainties in the calculations and experimental data used inits derivation but not for contingencies such as double batching or inaccuracies in analytical
determinations.
subsurface zone location (localisation des zones souterraines)
The release of sand, gel, cement or other material labelled with nuclear substances into a well during
fracturing or cementing operations to determine the depth and extent of a fractured or cemented zone.
This term is used as a licence use type.
success criterion (critère de réussite)
A criterion for a structure, system or component that designates the minimum functional capability andperformance levels required for effectiveness.
supernumerary day shifts (quarts de jour surnuméraires)
Periodic sequences of eight-hour day shifts that are built into a shift worker’s schedule.
supplementary equipment (équipement supplémentaire)
Equipment and instruments that are not installed as part of the original plant design, but are used as anadditional provision to mitigate the consequences of an accident. An example is the emergency mitigating
equipment (EME). Note: The use of EME is covered in the EME guidelines (EMEG).
surveillance (surveillance)
With respect to maintenance of nuclear facilities, activities carried out to confirm compliance with thesafe operating envelope (or with the operational limits and conditions, if applicable), to verify correct
operational states and to detect any abnormal condition before it can impair the ability of the structure,system or component to meet its design intent.
OR
With respect to safeguards, the collection of information through International Atomic Energy Agency(IAEA) inspector and/or instrumental observation aimed at detecting movements of nuclear material orother items, and any interference with containment or tampering with IAEA equipment, samples and data.
See also International Atomic Energy Agency inspector.
suspect item (article suspect)
An item that is suspected to be counterfeit, fraudulent or substandard.
sustainability (durabilité)
The capacity of a thing, action, activity, or process to be maintained indefinitely. (Source: Federal
Sustainable Development Act)sustainable development (développement durable)
Development that meets the needs of the present, without compromising the ability of future generations
to meet their own needs. (Sources: Canadian Environmental Assessment Act, 2012; Canadian
Environmental Protection Act, 1999; Federal Sustainable Development Act)

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Sv (Sv)See sievert.
systematic approach to training (SAT) (approche systématique à la formation [ASF])
A structured approach to training, composed of the following phases:• analysis: identification of training needs and of the knowledge, skills and attributes required toperform a particular job• design: conversion of the knowledge, skill and attribute requirements identified in the analysis intotraining objectives and the production of a training plan
• development: preparation of the training materials to meet the training objectives• implementation: training, using the training materials developed• evaluation: determination of the effectiveness of training in producing competent workers;
evaluation feedback is used as input to the other phases of SAT to ensure continued training
effectivenesssystematic fuel failure (défaillance systématique du combustible)
Fuel that had no known defect prior to an event, but that fails or exceeds the fuel integrity criteria definedin the version-controlled document or in the licensee documents requiring notification of change as aresult of the event.
systematic review (examen systématique)A review in which specified and appropriate methods are used to identify, appraise and summarize studies
addressing a defined question.
systems important to safety (SIS) (systèmes importants pour la sûreté [SIS])
Systems of a reactor facility associated with the initiation, prevention, detection or mitigation of any
failure sequence and that have an impact in reducing the possibility of damage to fuel, associated releaseof radionuclides or both.
OR
With respect to reliability programs for a reactor facility, those structures, systems and components of the
facility that are associated with the initiation, prevention, detection or mitigation of any failure sequenceand that have the most significant impact in reducing the possibility of damage to fuel, associated releaseof radionuclides or both.

Ttailings (résidus)
The waste material and water mixture left over after a mill removes the valuable rocks. The rock material
in tailings is usually the size of sand grains or smaller. Note: Tailings that result from uranium milling
contain long-lived radionuclides (such as thorium-230 and radium-226) produced from the decay of
uranium, as well as trace metals like arsenic and nickel. They also contain chemical residues from themilling process.

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tank (citerne)
Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: In the IAEA Regulations, tank means a portable tank (including a tank container), a road tankvehicle, a rail tank vehicle or a receptacle that contains solids, liquids or gases, having a capacity of notless than 450 litres when used for the transport of gases.
tare weight (masse à vide)
The weight of a container and/or packing material without the weight of the material it contains.
task (tâche)With respect to a systematic approach to training, a discrete segment of work that:• has two or more steps• has a definite beginning and end• constitutes a logical and necessary part of the duty and/or job of the individual who performs thisworktask list (liste des tâches)With respect to a systematic approach to training, the list of tasks that make up the requirements in a job
or duty area. The list should also include critical supporting references that provide insight into the scopeand difficulty of the tasks.
TBI (ICT)
total body irradiation
TBq (TBq)
terabecquerel, that is, 1012 becquerels; see becquerel.
teaching points (points à enseigner)With respect to a systematic approach to training, the elements that make up an evaluation objective:
discrete steps, skills, factors or concepts requiring separate demonstration or explanation that the trainee
must master, learn or do.
technical assessment (évaluation technique)An assessment based on available science, technical knowledge and analytical methods, to determine
whether submitted documents and supporting evidence meet legislative and regulatory requirements andexpectations, including codes, standards and best practices. Sometimes informally referred to as a
specialist review, technical review or review.
Technical Instructions for the Safe Transport of Dangerous Goods by Air (Instructions techniques pourla sécurité du transport aérien des marchandises dangereuses)
The document of that name, designated as Doc 9284, published by the International Civil Aviation
Organization, as amended from time to time. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
technical review (examen technique)
See technical assessment.

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technical staff (personnel technique)With respect to nuclear criticality safety, personnel with specific skills and experience who can help
implement CNSC regulatory requirements. Such personnel may include, but are not limited to, criticality
safety, health and safety, and facility process support personnel.
teletherapy machine (appareil de téléthérapie)
A device that is designed to deliver controlled doses of radiation in a collimated beam for therapeutic
purposes. (Sources: General Nuclear Safety and Control Regulations; Class II Nuclear Facilities andPrescribed Equipment Regulations)
temporary repair (réparation temporaire)
A repair that temporarily enables a failed or degraded structure, system or component to function
according to its original design until a permanent repair or replacement can be completed.
temporary storage (stockage temporaire)
Storage during the transportation cycle when a sealed source is unattended.
tenth-value layer (TVL) (couche d’atténuation au dixième [CAD])
The thickness of a shield or an absorber that reduces the radiation level to 10 percent of its initial level.
terabecquerel (TBq) (térabecquerel [TBq])
1012 becquerels; see becquerel.
terminal learning objective (TLO) (objectif d’apprentissage final)
A statement that describes the expected performance upon completion of specified training. The statement
includes a description, in operational terms, of what the individual must do, the condition under which theperformance must be completed, and the standard to which the performance must conform.
testing (essai)
For nuclear power plants, the observation or measurement of condition or functional indicators undercontrolled conditions to verify that the current performance of a structure, system or component conforms
to acceptance criteria.
therapeutic nuclear medicine (médecine nucléaire thérapeutique)
The administration of unsealed sources (nuclear substances) to humans for therapeutic purposes related totheir healthcare. Therapeutic nuclear medicine also includes the processing of radiopharmaceuticals andlaboratory studies that are part of the therapy.
thermography (thermographie)
A diagnostic technique that uses a thermograph to record the heat produced by different components.
thermoluminescent dosimeter (TLD) (dosimètre thermoluminescent [DTL])
A type of dosimeter used to monitor exposure to radiation. A TLD measures ionizing radiation exposure
by measuring the intensity of visible light emitted from a crystal in the detector when the crystal is heated.
The intensity of light emitted is dependent on the radiation exposure.

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threat and risk assessment (TRA) (évaluation de la menace et du risque [EMR])
An evaluation of the adequacy of an existing or a proposed physical protection system designed tosafeguard against(a) intentional acts that could pose a threat to the security of a high-security site; and(b) the exploitation of weaknesses in the physical protection measures of a high-security site.
(Source: Nuclear Security Regulations)
three-way communication (communication avec confirmation du message)
A method of verbal communication designed to reduce potential communication error. The initiator sends
a message, the receiver of the message repeats the message back to the initiator, and the initiator thenprovides confirmation to the receiver that the repeated message is correct.
thyroid burden (activité thyroïdienne)
The quantity of a radionuclide that has been deposited in the thyroid.
thyroid screening (dépistage thyroïdien)
The monitoring of workers for the purpose of detecting the presence of radioiodine deposited in the
thyroid as an indication of radioiodine intake. Note: Thyroid screening is not intended for quantitative
dose assessment.
TI (IT)
See transport index.
TIE (IET)
See toxicity identification and evaluation.
time-based maintenance (entretien en fonction de la durée)See periodic maintenance.
time-based overhaul (remise en état basée sur la durée)
An overhaul that is performed based on a set time period.
time-based preventive maintenance (entretien préventif basé sur la durée)
Maintenance performed on equipment in accordance with a set time period (predefined) or given amountof operation.
time-limited assumptions (TLA) (hypothèses limitées dans le temps)
Assumptions used in certain safety or design analyses specific to a facility or to a structure, system orcomponent (SSC) and that are based on an explicitly specified facility or SSC life. Some TLA examples
are metal fatigue calculation; pressurized thermal shock analysis; radiation-induced deformation andembrittlement; thermal aging; loss of material; and equipment qualification of electrical equipment,
instrumentation and control equipment, and cables.
tissue weighting factor (wT) (facteur de pondération tissulaire [wT])
The multiplier of the equivalent dose to an organ or tissue for the purpose of determining the effective
dose. The tissue weighting factors account for the different sensitivities of different organs and tissues tothe induction of stochastic effects of radiation.
TLA (hypothèses limitées dans le temps)
See time-limited assumptions.

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TLD (DTL)
See thermoluminescent dosimeter.
TLO (objectif d’apprentissage final)
See terminal learning objective.
TNA (ABF)
training needs analysis
total communications blackout (coupure complète des communications)
A situation where forms of electronic communications, such as traditional, cell and satellite phones, andWeb-based communications, are unavailable.
toxic (toxique)
See CEPA toxic.
toxicity identification and evaluation (TIE) (identification et évaluation de la toxicité (IET))
A process that identifies the toxic components of an effluent or ambient medium by chemicallymanipulating the effluent or medium and testing the resulting material.
TP (paramètre de déclenchement)
See trip parameter.
TRA (EMR)
See threat and risk assessment.
tracer studies (étude à partir de traceurs)
The field use of nuclear substances for industrial, environmental or research purposes other thansubsurface tracer studies.
trained and qualified (formé et qualifié)
Having a specified level of knowledge, skills, attitudes and experience to meet job performancerequirements.
trainee characteristics (profil des stagiaires)
The target population for whom the proposed training is intended as well as relevant information about
the trainees concerned, such as the aptitudes, special skills, education, previous related training andpersonal data (such as age). Defining trainee characteristics is a component of a training system.
trainee evaluation (évaluation des stagiaires)
The assessment of progress made by participants during an instructional program (formative evaluation)and of their achievement at the end of the program (summative evaluation).
training (formation)
A combination of activities with the purpose of providing the knowledge, skills and attitudes toindividuals or teams in order to allow performance of activities in an effective and efficient manner and to
identified criteria. Also called instruction.
training development plan (plan d’élaboration de la formation)
A document that describes how the output of the analysis and design phases is intended to be used during
the development to meet the requirements of the terminal learning objectives and enabling objectives.

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training plan (plan de formation)
See training development plan.
training program (programme de formation)
A structured collection of courses required for achieving a qualification or certification to perform work.
Also called instructional program.
training system (système de formation)
A series of training-related processes and procedures that provides the basis for the analysis, design,development, implementation, evaluation, documentation and management of training programs andcourses.
transaction (transaction)
Any action involving an import or an export.
transfer (transférer)Move nuclear material, both domestic (between Canadian material balance areas) and foreign (imports
and exports). Note: This definition applies specifically to nuclear material accounting.
OR
Change possession of a nuclear substance or radiation device from one licensee to another where both arelocated within Canada.
OR
Move a nuclear substance or radiation device from one location to another, where both places are locatedwithin Canada.
OR
See export or import.
transit (transit)
The process of being transported through Canada after being imported into and before being exported
from Canada, in a situation where the place of initial loading and the final destination are outside Canada.
(Sources: General Nuclear Safety and Control Regulations; Nuclear Non-proliferation Import and Export
Control Regulations; Packaging and Transport of Nuclear Substances Regulations, 2015)transport (transport)
The handling, carrying or storage in transit and receipt at the final destination of packages. Transport
includes normal and accident conditions encountered in carriage and in storage during transit.
transport index (TI) (indice de transport [IT])Has the same meaning as in the IAEA Regulations. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Note: The TI is a number assigned to a package, overpack, freight container, or to unpackaged LSA-I or
SCO-I, used to provide control over radiation exposure.
transuranic element (élément transuranien)
Any chemical element that has an atomic number greater than 92 (the atomic number of uranium).
trending (établissement des tendances)
With respect to nuclear criticality safety, the extrapolation of data from periodic non-destructive
measurements of a control Raschig ring’s physical and chemical properties, and from certain properties ofthe vessel, to predict changes with time in the properties measured.

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tribology (tribologie)
The systematic study of friction and its effects.
trip (déclenchement)
See reactor trip.
trip parameter (TP) (paramètre de déclenchement)
A measurement of a variable that is used to trigger a safety system action when the trip parameter set
point is reached.
trip parameter set point (valeur seuil de déclenchement)
The trip parameter value at which activation of a safety system is triggered.
tritium (T or 3H) (tritium)
A radioisotope (symbol T or 3H) of the element hydrogen, composed of one proton and two neutrons.
trusted third party (tierce partie de confiance)
A private organization or agency that is in partnership with the Canadian Police Information Centre (orequivalent) for the purposes of conducting name-based criminal record verifications.
OR
A private organization or agency contracted by a licensee for the purposes of conducting reference
verifications.
TVL (CAD)
See tenth-value layer.
Type I inspection (inspection de type I)
A systematic, planned and documented process to determine, through objective evidence, whether alicensee program, process or practice complies with the regulatory requirements as expressed in thecompliance criteria associated with the inspection. Also called audit; evaluation.
Type II inspection (inspection de type II)
A planned and documented activity to verify the results of licensee processes and not the processes
themselves. Type II inspections are typically routine (item-by-item checklist) inspections and rounds ofspecified equipment and/or facility material systems, or of discrete records, products or outputs fromlicensee processes.
Type A (type A)
In respect of a package, means that the package is designed in accordance with the applicablerequirements of the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
Type B (type B)
In respect of a package, means that the package is classified as either a Type B(U) or a Type B(M)package in accordance with the IAEA Regulations and is designed in accordance with the applicablerequirements of those Regulations. (Source: Packaging and Transport of Nuclear Substances
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Type C (type C)
In respect of a package, means that the package is designed in accordance with the applicablerequirements of the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
Type H(M) (type H[M])
In respect of a package, means that the package has a type code of H(M) in accordance with the IAEA
Regulations and is an excepted package, Type IP-1 package, Type IP-2 package, Type IP-3 package orType A package that is designed to contain more than 0.1 kg of uranium hexafluoride that is non-fissile
material or is fissile-excepted radioactive material. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Type H(U) (type H[U])
In respect of a package, means that the package has a type code of H(U) in accordance with the IAEA
Regulations and is an excepted package, Type IP-1 package, Type IP-2 package, Type IP-3 package orType A package that is designed to contain more than 0.1 kg of uranium hexafluoride that is non-fissile
material or is fissile-excepted radioactive material. (Source: Packaging and Transport of Nuclear
Substances Regulations, 2015)
Type IP-1 (type IP-1)
In respect of a package, means that the package is designed in accordance with the applicablerequirements of the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
Type IP-2 (type IP-2)
In respect of a package, means that the package is designed in accordance with the applicablerequirements of the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)
Type IP-3 (type IP-3)
In respect of a package, means that the package is designed in accordance with the applicablerequirements of the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations, 2015)

U
U (U)
See uranium or use factor.
UA (IN)
unacceptable; see safety performance rating methodology
UL (UL)
Underwriters Laboratories (UL) is a global independent safety science company offering expertise acrossfive key strategic businesses: product safety, environment, life and health, university, and verification
services.
ULC (ULC)
Underwriters Laboratories of Canada (ULC) is an independent product safety testing, certification andinspection organization.

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ultimate heat sink (source froide d’ultime secours)
A medium into which the transferred residual heat from nuclear fuel can always be accepted, even if allother means of removing the heat have been lost or are insufficient. This medium is normally a body ofwater or the atmosphere.
unacceptable (UA) (inacceptable [IN])See safety performance rating methodology.
uncertainty analysis (analyse d’incertitude)
The process of identifying and characterizing the sources of uncertainty in an analysis, evaluating theirimpact on the analysis results, and developing, to the extent practicable, a quantitative measure of this
impact.
uncertainty in the bias (incertitude liée au biais)
A measure of both the accuracy and the precision of the calculations and uncertainty of data.
unconditional clearance level (niveau de libération inconditionnelle)
In respect of a bulk quantity of material, except for surface contaminated material, in which theradioactive nuclear substance is uniformly distributed, means an activity concentration that(a) in respect of a radioactive nuclear substance set out in column 1 of Schedule 2, is the corresponding
activity concentration set out in column 2;(b) in respect of a radioactive nuclear substance that is not set out in column 1,(i) is 1 Bq/g, if the atomic number of the substance is equal to or less than 81,(ii) is 1 Bq/g, if the atomic number of the substance is greater than 81 and the substance, or its shortlived radioactive progeny, does not emit alpha radiation, and(iii) is 0.1 Bq/g, if the atomic number of the substance is greater than 81 and the substance, or its
short-lived radioactive progeny, emits alpha radiation; or(c) in respect of more than one radioactive nuclear substance – except for thorium-232, uranium-235,
uranium-238 and their radioactive progeny mentioned in paragraph 4.3 of the IAEA Safety Standard
RS-G-1.7 – is the quotient obtained by dividing the total activity concentration by the sum of
quotients obtained by dividing the activity concentration of each radioactive nuclear substance by its
corresponding activity concentration as referred to in paragraph (a) or (b).
(Source: Nuclear Substances and Radiation Devices Regulations)
Note: Bq/g means becquerels/gram.
unified uranium (uranium unifié)
A category of uranium, used for nuclear material accounting and reporting purposes under the Safeguards
Agreement, through which all uranium (natural, depleted and enriched) is included in a single (unified)account.
unirradiated thorium (thorium non irradié)
As defined in the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances
Regulations 2015)
Note: In the IAEA Regulations, unirradiated thorium means containing not more than 10-7 grams ofuranium-233 per gram of thorium-232.
unit 0 operator (opérateur de la tranche 0)
The person in a multi-unit nuclear power plant (NPP) who is responsible for operating and monitoring agroup of safety and process systems common to all reactor units from the main control room unit 0
panels, in accordance with the NPP licence, policies and procedures.

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unsealed source (source non scellée)
A source other than a sealed source. (Source: Nuclear Substances and Radiation Devices Regulations)
Note: These nuclear substances are in a physical form where dispersion of the radioactive material ispossible during use or handling. Usually a liquid, they may also be in solid, powder or gaseous form.
Unsealed sources are commonly used in medical diagnostic and therapeutic treatments, as well as inlaboratory research applications. Also called open source.
update training (formation de mise à jour)See continuing training.
upper subcritical limit (USL) (limite supérieure de sous-criticité [LSSC])
The maximum allowed value of the calculated effective multiplication factor (keff) or of a singleparameter subcritical limit, under both normal and credible abnormal conditions, including allowance forthe bias, uncertainty in the bias, and an administrative margin of subcriticality.
uprate (augmentation de puissance)
The action of increasing a nuclear power plant’s output capacity.
uranium (U) (uranium)
See depleted uranium, enriched uranium or natural uranium.
uranium concentrate (concentré d’uranium)
A product with a high abundance in uranium obtained by physical and chemical treatments, requiring
further refinement before it is suitable for nuclear use. Uranium concentrate from a mill is upgraded byrefining and converting it to uranium trioxide (UO3), and subsequently into uranium dioxide (UO2) (usedin Canada) and uranium hexafluoride (UF6) (exported). Also called yellowcake.
uranium ore concentrate (concentré de minerai d’uranium)
See uranium concentrate.
urine specimen collector (personne chargée du prélèvement des échantillons d’urine)
A trained person who instructs and assist workers at a urine collection site, receives the specimen
provided by each worker and performs an initial inspection of that specimen, and initiates and completesa custody control form for that specimen.
usability (capacité d’utilisation)
The extent to which a product can be used by specified users, to achieve specified goals, witheffectiveness, efficiency and satisfaction in a specified context of use.
use (utiliser)
Manipulate or handle nuclear substances and radiation devices; operate radiation devices. Note: Thisdefinition applies to nuclear substances and radiation devices.
used fuel pool (piscine de combustible usé)
See wet storage bay.

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used nuclear fuel (combustible usé)
Used fuel assemblies removed from a reactor after several years use and treated as waste. Also called
irradiated nuclear fuel; spent fuel. Note: In Canada, “irradiated nuclear fuel” or “used nuclear fuel” is amore accurate term for “spent fuel” (a term used internationally and in some Canadian reports with thesame meaning in this definition, to align with international agreements and conventions), because
discharged fuel is considered a waste material even when it is not fully spent.
use factor (U) (facteur d’utilisation [U])The fraction of the total workload during which a radiation field is present at a particular location. Thisfactor (≤1) is multiplied by the workload and occupancy factor at that location, to derive the maximum
personal dose any single person would be expected to receive.
use type (type d’utilisation)
The purpose for which a licence has been issued.
USL (LSSC)
See upper subcritical limit.
U.S. NRC (U.S. NRC)
See U.S. Nuclear Regulatory Commission.
U.S. Nuclear Regulatory Commission (U.S. NRC) (Nuclear Regulatory Commission des États-Unis[NRC des États-Unis])
The agency of the U.S. federal government responsible for regulating commercial nuclear power plants
and other uses of nuclear materials through licensing, inspection and enforcement of its requirements.

Vvalidated computational technique (technique de calcul validée)With respect to nuclear criticality safety, a calculation technique that has been validated in conformancewith the CNSC’s guidance for nuclear criticality safety.
validation (validation)
The process of checking or proving the accuracy of a model, method or procedure against expected
requirements.
OR
For human factors, the process of determining the degree to which a human–machine system design andsupporting mechanisms facilitate the achievement of overall safety and operational goals.
OR
For emergency preparedness, an evaluation using performance-based tests to determine whether the
integrated design of a system (equipment, procedure and personnel elements) meets performancerequirements and acceptably supports safe operations.

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valued component (VC) (composante valorisée [CV])Environmental features that may be affected by a project and that have been identified to be of concern by
the proponent, government agencies, Aboriginal peoples or the public. (Source: Practitioners Glossary
for the Environmental Assessment of Designated Projects Under the Canadian Environmental Assessment
Act, 2012 [1])Note 1: The value of a component not only relates to its role in the ecosystem, but also to the value
people place on it. For example, it may have been identified as having scientific, social, cultural,
economic, historical, archaeological or aesthetic importance. For the purposes of [the Canadian
Environmental Assessment Act (CEAA 2012)], valued components are selected in relation to section 5 of
CEAA 2012 and taking into account direction provided by the responsible authority, or in the case of an
EA by review panel, by the [Canadian Environmental Assessment Agency] or the Minister [ofEnvironment and Climate Change]. (Source: Practitioners Glossary for the Environmental Assessment of
Designated Projects Under the Canadian Environmental Assessment Act, 2012 [1])Note 2: VCs are selected from the abiotic and biotic information collected as part of the baselinecharacterization. They may be surrogate organisms rather than actual plant or animal species (forexample, a theoretical benthic feeding fish species), communities (for example, a benthic
macroinvertebrate community) or specific species (for example, an endangered species), but may also
include significant ecological features of the environment, such as wetlands.
valued ecosystem component (VEC) (composante valorisée de l’écosystème [CVE])
See valued component.
VC (CV)See valued component.
VEC (CVE)
See valued component.
vehicle (véhicule)
Means any means of air, water or land transport, and includes railway equipment within the meaning
assigned to that expression by subsection 4(1) of the Railway Safety Act. (Source: Nuclear Safety andControl Act)vehicle portal (sas pour véhicule)
A structure situated on the perimeter of a protected area that is enclosed on the sides and consists of two
movable gates, separated by a space sufficiently large to accommodate land vehicles having an
operational requirement to enter the area. (Source: Nuclear Security Regulations)vendor/contractor (fournisseur/entrepreneur)
A person who is either contracted by a licensee to develop or deliver training, or who delivers training toa licensee’s staff with the intent that a required qualification would be granted upon completion of the
training.
verification (vérification)
The act of reviewing, checking or inspecting to confirm that specified requirements have been met.
OR
For human factors, the process of demonstrating that equipment and systems have been designed as
specified, and that adherence to human factors guidelines has been maintained.

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verified positive drug test (test de dépistage de drogues positif)
With respect to fitness for duty, a drug test result issued by a laboratory accredited by the Substance
Abuse and Mental Health Services Administration, and which has undergone review by a medical review
officer who has determined that it is a positive test result for which no legitimate medical explanation has
been provided. See also accredited laboratory; medical review officer.
version-controlled document (document contrôlé)With respect to reporting requirements for nuclear power plants, a document that is subject to version
control due to its inclusion in the licence conditions handbook. Note: Such documents include regulatory
documents or Canadian and international standards as referenced in the licence (and may include
documents or Canadian and international standards that require transition). Version-controlled documents
may also include key licensee documents, such as documents requiring consent of change (as per alicence condition). Each version-controlled document includes a unique identifier that can be clearlyreferenced.
vessel (colonne [ou réservoir])Any seagoing vessel or inland waterway craft used for carrying cargo.
OR
With respect to nuclear criticality safety, a container designed to hold a solution, including any volume
within which criticality control is provided by Raschig rings.
violation (violation)
Failure to comply with:• a provision of the Nuclear Safety and Control Act (NSCA) or the regulations made under the NSCA
• an order or decision made under the NSCA
• a licence term or condition
vital area (zone vitale)
An area inside a protected area containing equipment, systems, devices or a nuclear substance, thesabotage of which would or would likely pose an unreasonable risk to the health and safety of persons
arising from exposure to radiation. (Source: Nuclear Security Regulations)
VSLORC (perte très lente de contrôle de la réactivité)
very slow loss of reactivity control

W
WANO (WANO)
See World Association of Nuclear Operators.
waste management SCA (DSR Gestion des déchets)
A safety and control area (SCA) that covers internal waste-related programs that form part of the facility’s
operations up to the point where the waste is removed from the facility to a separate waste management
facility. This area also covers the planning for decommissioning. This SCA is one of the 14 within the
CNSC SCA Framework.

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waste management system (système de gestion des déchets)
A system for collecting, transporting, receiving, treating, processing, storing or disposing of the wastes
that are produced as a result of the licensed activity at a uranium mine or mill. (Source: Uranium Minesand Mills Regulations)
Note: More generally, all licensed nuclear facilities (not only uranium mines and mills) have waste
management systems.
waste nuclear substance activities (activités liées aux déchets de substances nucléaires)
Activities in relation to waste nuclear substances that are not located at a Class I or a Class II nuclear
facility or at a mine or mill. (Source: Canadian Nuclear Safety Commission Cost Recovery Fees
Regulations)waste rock (stériles)
Rock that does not contain any minerals in sufficient concentration to be considered ore, but which must
be removed in the mining process to provide access to the ore. Waste rock includes both mineralized andclean waste rock.
water frequented by fish (eaux où vivent des poissons)
Canadian fisheries waters. (Source: Fisheries Act)
weapon (arme)
Anything that could be used or is capable of being used to jeopardize the security of a nuclear facility or a
nuclear substance or anything, including firearms, that is used, designed to be used or intended for use incausing death or injury to any person or for the purpose of threatening or intimidating any person.
(Source: Nuclear Security Regulations)weight data (données de masse)
The numeric label and the element or isotope weight of an item or batch of nuclear material. Thisdefinition applies to nuclear material accounting.
wet storage bay (piscine de stockage)
A large pool of water where radioactive material (mainly fuel discharged from a nuclear reactor) is cooled
and shielded until it is safe to remove to dry storage. Also called fuel bay; irradiated fuel bay; spent fuelbay; storage bay; storage pool; used fuel pool.
WHMIS (SIMDUT)
Workplace Hazardous Materials Information Systemwipe test (épreuve de contamination par frottis)
An indirect form of contamination monitoring that involves wiping a suspect surface and measuring thenuclear substances collected on the wipe sample.
WL (WL)See working level.
WLM (WLM)
See working level month.

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worker (travailleur)A person who performs work that is referred to in a licence. (Sources: General Nuclear Safety andControl Regulations; Class I Nuclear Facilities Regulations; Class II Nuclear Facilities and Prescribed
Equipment Regulations; Nuclear Substances and Radiation Devices Regulations; Radiation Protection
Regulations; Uranium Mines and Mills Regulations)
Note: This definition applies to contractors and to subcontractors, as well as to workers directly employed
by a licensee.
workers’ representative (représentant des travailleurs)
Means:(a) a person who is a member of the workers’ safety and health committee;(b) the workers’ safety and health representative;(c) where there is no person referred to in paragraph (a) or (b), the workers’ collective bargaining agent;or(d) where there is no person referred to in paragraph (a), (b) or (c), a worker.
(Source: Uranium Mines and Mills Regulations)working level (WL) (unité alpha [WL])
The concentration of radon progeny in 1 m3 of air that has a potential alpha energy of 2.08 x 10-5 J.
(Source: Radiation Protection Regulations)working level month (WLM) (unité alpha-mois [WLM])
The exposure that results from the inhalation of air containing one working level for 170 hours.
(Source: Radiation Protection Regulations)
Note: This unit of measure is used to express the level of exposure to radon decay products.
workload (charge de travail)With respect to Class II prescribed equipment or radiation devices, a parameter that characterizes theamount of use over a defined period and that is directly related to the resulting radiation doses received bypersons occupying adjacent areas over that period. Workload is typically calculated in grays per year atsome reference distance from the source of radiation, for a specified source location.
work package (WP) (ensemble de travaux)
A logical grouping of relatively contiguous tasks aimed at achieving a particular step in the overall
project. For example, in a decommissioning project, the removal of a specific facility component(including, as necessary, its decontamination, disassembly and delivery to a waste segregation area) could
constitute a single work package.
workplace (lieu de travail)Any area within a uranium mine or mill where a worker could reasonably be expected to be in the courseof performing work. (Source: Uranium Mines and Mills Regulations)
Note: More generally, this term also applies to all licensed nuclear facilities.
workplace air sampler (WPAS) (échantillonneur d’air sur le lieu de travail [WPAS])An air sampler, consisting of a filter holder and vacuum pump, mounted in a working area to estimate
breathing zone concentrations of radionuclides.

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World Association of Nuclear Operators (WANO) (Association mondiale des exploitants de centrales
nucléaires [WANO])
A non-profit organization with the mission of maximizing the safety and reliability of nuclear power
plants worldwide by working together with its members to assess, benchmark and improve performancethrough mutual support, exchange of information and emulation of best practice.
WP (ensemble de travaux)
See work package.
WPAS (WPAS)
See workplace air sampler.
wR (wR)See radiation weighting factor.
wT (wT)
See tissue weighting factor.

X-Y-Z
X-ray radiation (rayons X)
Electromagnetic radiation that consists of photons originating from outside an atom’s nucleus.
yellowcake (yellowcake)See uranium concentrate.
Zangger Committee (Comité Zangger)
A multilateral export control regime, formed as the Treaty on the Non-Proliferation of Nuclear Weapons’(NPT) Exporters Committee, that serves as the “faithful interpreter” of article III(2) of the NPT in order toinform the interpretation of nuclear export control policies for treaty members. The Zangger Committee
maintains a “Trigger List” (International Atomic Energy Agency Information Circular 209(INFCIRC/209 [12]), triggering safeguards as a condition of supply) of nuclear items to assist NPT
parties in identifying equipment and materials subject to export controls.

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Appendix A: Acronyms and Abbreviations
ACR (RAC)AECL (EACL)
ALARA (ALARA)
ALI (LAI)
AM (GV)AMP (SAP ou PGV)

annual compliance report
Atomic Energy of Canada Limited
as low as reasonably achievableannual limit on intake
aging managementadministrative monetary penalty
Note: AMP has also been used for aging management program / aging
management plan but is now reserved for administrative monetary penalty
ANO (ONA)
authorized nuclear operator; see reactor operator
ANS (ANS)
American Nuclear Society
ANSI (ANSI)
American Nuclear Standards InstituteAOO (IFP)
anticipated operational occurrence
ASDV (VDVA)
atmospheric steam discharge valve
ASME (ASME)
a professional association, founded as the American Society of MechanicalEngineers
BATEA (MTEAR)
best available technology and techniques economically achievable
BDBA (AHD)
beyond-design-basis accident
BDBE (SHD)
beyond-design-basis earthquake
BDBT (MHD)beyond-design-basis threat
BDCP (PCSE)
by-difference correction principle
BE (IA)
below expectations; see safety performance rating methodology
BEAU (BEAU)
best estimate and uncertainty (BEAU) method
Bq (Bq)becquerel
BWR (REB)
boiling water reactor
CANDU (CANDU)
CANada Deuterium Uranium
CASA (ESAC)
criticality accident sequence assessment
CCF (DCC)
common-cause failure
CCME (CCME)
Canadian Council of Ministers of the Environment
CEAA 2012 (LCEE 2012) Canadian Environmental Assessment Act, 2012
CEDO (OAEA)
certified exposure device operator
CEPA (LCPE)
Canadian Environmental Protection Act, 1999
CFSI (CFSI)
counterfeit, fraudulent and suspect items; see also counterfeit item,
fraudulent item and suspect item
CHF
critical heat flux
Ci (Ci)curie; see becquerel
CM
configuration management or corrective maintenance
CMD (CMD)
Commission member document
CNS (CSN)
Convention on Nuclear Safety
CNSC (CCSN)
Canadian Nuclear Safety Commission
COPC (CPP)
contaminant of potential concern
CRDM
control rod drive mechanism
CRNC (VNCJ)
criminal records name check152

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CRO (OSC)CSA (CSA)
CSC (CSC)CSDV (SEVC)CSI (CSI)
CVC (CVC)
D (D)DA (AD
DAC (LDCA)
DBA (AD)DBE (SR)DBT
DCF (FCD)
DEC (CAD)
DGR (DGP)
DIL (NED)DO
DRL (LRD)E (E)
EA (EE)ECCS (SRUC)EFPD (JEPP)
EFPH (HEPP)EHRS (SEUC)
EIR (RIE)
EIS (EIE)
Ekg (kgE)
ELAP (PPACA)
EME (EAU)EMS (SGE)
EO
EPR (EPE)EPREV (EPREV)EPS (AEU)
EQ (QE)ERA (ERE)ERO (OIU)
ESC (CSU)
ESWS (SSUAE)eV (eV)
FAI (MPF)
FERP (PFIU)
FFDFINAS (FINAS)REGDOC-3.6, Glossary of CNSC Terminology

control room operator; see reactor operator
Canadian Standards Association; now called CSA Group
criticality safety control; see nuclear criticality safety control
condenser steam discharge valve
criticality safety index
compliance verification criteria
absorbed dose
derived activity
derived air concentration
design-basis accident
design-basis earthquake
design-basis threat
dose conversion factor
design extension conditions
deep geological repository
derived investigational level
designated officer
derived release limit
effective dose
environmental assessment
emergency core cooling system
equivalent full-power day
equivalent full power hour.
emergency heat removal system
event initial reportenvironmental impact statement
effective kilogram
extended loss of AC power
emergency mitigating equipment
environmental management systemenabling objective
environmental protection review
Emergency Preparedness Review (an IAEA service)
emergency power supply
environmental qualification
environmental risk assessment
emergency response organization
emergency support centre
emergency secondary water supply systemelectron volt
Fukushima action item
Federal Emergency Response Plan
fitness for duty
fuel incident notification and analysis system

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FLORC (PRCR)FNEP (PFUN)
FS (ES)FV (FV)FY (exerice)
GAI (DG)
GAR (REG)
GBq (GBq)
GSS (EAG)GWD (GWj)
Gy (Gy)HAC
HCLPF
HDR (HDD)
HEU (UHE)HEUNL (NULHE)HF (FH)
HFE (IFH)
HOP (RHO)HT (HT)
HTO (HTO)HTSHVL (CDA)HVT (CDA)
H/X (H/X)
IAA (LEI)
IAEA (AIEA)
I&C (IC)ICAO (OACI)ICRP (CIPR)ICRU (CIUMR)IEMP (PISE)IFBIIP (PIMO)IL (NE)IMRT (RCMI)
INES (INES)
INFCIRC (INFCIRC)
INPO (INPO)IPPAS (SCIPP)
IRD (DRI)IRRS (SEIR)IRS (IRS)ISAR (ISAR)REGDOC-3.6, Glossary of CNSC Terminology

fast loss of reactivity control
Federal Nuclear Emergency Planfully satisfactory; see safety performance rating methodology
Fussell-Vesely; see importance measures
fiscal year
generic action item
global assessment report; see global assessment
gigabecquerel, that is, 109 becquerels; see becquerel
guaranteed shutdown state
gigawatt-daysgrayhypothetical accident conditions
high confidence of low probability of failure
high dose rate (HDR) brachytherapy remote afterloader
high-enriched uranium
highly enriched uranyl nitrate liquid
human factors
human factors engineering; see human factors in design
human and organizational performanceequivalent dosehydrogenated tritium oxide; also called tritiated water
primary heat transport systemhalf-value layer
half-value thickness; see half-value layerhydrogen-to-fissile atomic ratio
Impact Assessment Act
International Atomic Energy Agency
instrumentation and control
International Civil Aviation Organization
International Commission on Radiological Protection
International Commission on Radiation Units and Measurements
Independent Environmental Monitoring Program
irradiated fuel bay; see wet storage bay
integrated implementation plan
investigational level
intensity modulated radiation therapy
International Nuclear and Radiological Event Scale
Information Circular (IAEA publication)
Institute of Nuclear Power Operations
International Physical Protection Advisory Service
immediate rapid deployment
Integrated Regulatory Review Service
International Reporting System for Operating Experience
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ISI
ISO (ISO)ISR (EIS)KI (KI)LBB (FAR)
LBLOCA (APRPGB)
LCH (MCP)LCMP (PGV)LDRM (MRFD)
LET (TLE)
LEU (UFE)
LLOCA (APMRP)LLRD (PRLP)
LLW (DFA)
LOCA (APRP)LOE (ELE)LOF
LPOLPSWOS (CESBP)LRF (FGER)LTO
LWR (REO)
MAPS
MBA (ZBM)
MB Code (code MB)
MBq (MBq)
MCR (SCP)MDC (CDM)
MeV (MeV)
MMC (CMM)
MMR (MRM)
MRO (ME)MSDS (FS)MSIV (VIPV)
MTL (NME)MTU (MTU)
MU (UM)
MUF
NCB (OCN)
NCS (SCN)
NCSE (ESCN)NDR (FDN)REGDOC-3.6, Glossary of CNSC Terminology

in-service inspection
International Organization for Standardization
integrated safety review; see periodic safety review
potassium iodide
leak before breaklarge-break loss-of-coolant accident; see loss-of-coolant accident
licence conditions handbook
lifecycle management plan; see aging management program / aging
management plan
low dispersible radioactive material
linear energy transfer
low-enriched uranium
large loss-of-coolant accident; see loss-of-coolant accident
long-lived radioactive dust
low-level waste
loss-of-coolant accident
limit of operating envelope
location outside facilities
last person out
low-pressure service water open systemlarge release frequency
long-term operation
light-water reactor
minimum allowable performance standards
material balance area
measurement basis code
megabecquerel, that is, 106 becquerels; see becquerel
main control roommaterial description code
megaelectron volt
minimum measurable concentration
micro modular reactor; see reactor facility
medical review officer
material safety data sheet
main steam isolation valve
minimum testing level
metric tonne of uranium
monitor unit
material unaccounted for; see inventory difference
National Non-Destructive Testing (NDT) Certification Body
nuclear criticality safety
nuclear criticality safety evaluation
National Dose Registry155

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NDT (END)

non-destructive testing; see also National Non-Destructive Testing (NDT)
Certification Body
nuclear emergency management
Nuclear Emergency Organization
nuclear energy worker
NOA – NO ADVERSE INFO or Notice of Assessment (NOA) –INSUFFICIENT INFO
nuclear power plant
Treaty on the Non-Proliferation of Nuclear Weapons (also referred to as theNon-Proliferation Treaty or the Nuclear Non-Proliferation Treaty)
National Research Council or U.S. Nuclear Regulatory Commission
Nuclear Safety and Control Act
Nuclear Suppliers Group
nuclear security officer
organically bound tritium
on-the-job training
operational limits and conditions
operating policies and principles
operating experiencepassive autocatalytic recombiner; also called passive autocatalytic hydrogen
recombiner
personal air sampler
pressure boundary degradation
pulsed dose rate
Provincial Emergency Operations Centre
positron emission tomography
primary heat transport system
performance indicator
postulated initiating event
potential intake fraction
physical inventory verification
personal protective equipment
physical protection system or preferred power supply
probabilistic risk analysis or probability risk assessment; see probabilistic
safety assessment
power reactor operating licence
primary relief valve
probabilistic safety assessment
preliminary safety analysis reportperiodic safety review
pressurized water reactor
quality management
responserisk achievement worth; see importance measuresroot-cause analysis

NEM (GUN)
NEO (OUN)NEW (TSN)NOANPPNPT (TNP)NRC
NSCA (LSRN)NSG (GFN)NSO (ASN)
OBT (TLCO)
OJT
OLC
OP&P (LCE)
OPEX (OPEX)PAR
PAS (EAP)PBD (DEP)PDR (DDP)
PEOC (CPOU)
PET (TEP)
PHTS (CCP)PI
PIE (EIH)
PIF (FIP)PIV (VSP)
PPE (EPI)
PPS (SPP or AEP)
PRA (EPS)PROL (PERP)PRV (VDV)PSA (EPS)PSAR (RPAS)
PSR (BPS)PWR (REP)QM (GQ)
R (R)RAW (RAR)
RCA

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RCM (MAF)
RCS (SRR)
RDR (RRR)
RIR (RAR)
RPPE (EPIR)
RRW (RRR)
RSDS (FSR)
RSO (RRP)
SA (SA)SAD
SAM (GAG)SAMG (LDGAG)
SAR (RAS)
SAT (ASF)
SBO (PETC)SCA (DSR)SCDF (FDGC)SCO (SCO)
SCR (SCA)
SD (arrêt)SDCS (CRA)
SGECS (SRUGV)SHP
SI (SI)SIS (SIS)
SM (GQ)
SMR (VMS ou PRM)
SNF
SOE (PES)SOR (BA)SPISRS (SRS)SS
SSC (SSC)
SSD
SSS
SStrA (ERMCE)
Sv (Sv)
TBI (ICT)TBq (TBq)
TI (IT)
TIE (IET)REGDOC-3.6, Glossary of CNSC Terminology

reliability-centred maintenancereactor coolant systemrisk decrease ratio; see importance measuresrisk increase ratio; see importance measuresradiation personal protective equipment
risk reduction worth; see importance measuresradiation safety data sheetsradiation safety officer
satisfactory; see safety performance rating methodology
source axis distancesevere accident management (SAM) program
severe accident management guidelines; see severe accident management(SAM) programsafety analysis reportsystematic approach to training
station blackout
safety and control area
severe core damage frequency
surface contaminated object
secondary control room
shutdown
shutdown cooling systemsteam generator emergency cooling systemsenior health physicist
International System of Units (Système international d’unités)systems important to safety
shift manager; see plant shift supervisor
scheduled maintenance release or security monitoring room or small modular
reactor (see reactor facility)
spent nuclear fuel; see used nuclear fuelsafe operating envelope
shutoff rod
safety performance indicatorsafety-related systems
shift supervisor; see plant shift supervisor
structures, systems and components
source skin distancesafe shutdown statesite selection threat and risk assessment
sievert
total body irradiation
terabecquerel, that is, 1012 becquerels; see becquereltransport index
toxicity identification and evaluation

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TLA
TLD (DTL)
TLO
TNA (ABF)TPTRA (EMR)
TVL (CAD)U (U)UA (IN)USL (LSSC)
U.S. NRC (U.S. NRC)
VC (CV)
VEC (CVE)VSLORCWANO (WANO)
WHMIS (SIMDUT)WL (WL)WLM (WLM)WPWPAS (WPAS)wR (wR)wT (wT)REGDOC-3.6, Glossary of CNSC Terminology

time-limited assumptions
thermoluminescent dosimeter
terminal learning objective
training needs analysis
trip parameter
threat and risk assessment
tenth-value layer
uranium or use factor
unacceptable; see safety performance rating methodology
upper subcritical limit
U.S. Nuclear Regulatory Commission
valued component
See valued component
very slow loss of reactivity control
World Association of Nuclear Operators
Workplace Hazardous Materials Information System
working levelworking level monthwork package
workplace air sampler
radiation weighting factor
tissue weighting factor

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References
1. Canadian Environmental Assessment Agency, Practitioners Glossary for the Environmental
Assessment of Designated Projects Under the Canadian Environmental Assessment Act, 2012,
Ottawa, Canada. 2013
2. International Atomic Energy Association (IAEA), Safety Standard RS-G-1.7, Application of theConcepts of Exclusion, Exemption and Clearance, Vienna, 2004.
3. CSA Group, CSA N288.1-014, Guidelines for calculating derived release limits for radioactive
material in airborne and liquid effluents for normal operation of nuclear facilities, 2014.
4. CSA Group, CSA-N289.1-08, General requirements for seismic design and qualification of CANDU
nuclear power plants, Canada, published in 2008, reaffirmed in 2013.
5. CSA Group, CSA N288.6, Environmental risk assessments at Class I nuclear facilities and uranium
mines and mills, Canada, published in 2012, reaffirmed in 20176. IAEA Information Circular 254 (INFCIRC/254), Communications Received from Certain Member
States Regarding Guidelines for the Export of Nuclear Material, Equipment or Technology, Vienna,
Austria
7. Government of Canada, A Framework for the Application of Precaution in Science-based Decision
Making about Risk, Ottawa, Canada, 2003
8. IAEA, Code of Conduct on the Safety and Security of Radioactive Sources, Vienna, Austria
9. CSA Group, CSA-N285.0-08, General requirements for pressure-retaining systems and components
in CANDU nuclear power plants, Canada, 2008.
10. IAEA, Safety Standards Series SF-1 Fundamental Safety Principles, 2006.
11. IAEA, Protocol Additional to the Agreement between Canada and the International Atomic Energy
Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of
Nuclear Weapons, IAEA INFCIRC/164/Add 1, 2000
12. IAEA Information Circular 209 (INFCIRC/209), Communications Received from Members
Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other
Material, Vienna, Austria
13. CSA Group CSA N292.1-16, Wet Storage of Irradiated Fuel and Other Radioactive
Materials, Canada 2016.

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Additional Information•

International Atomic Energy Association, IAEA Safety Glossary, Vienna, 2007•

United States Nuclear Regulatory Commission, Glossary, updated February 2015160

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CNSC Regulatory Document Series
Facilities and activities within the nuclear sector in Canada are regulated by the CNSC. In addition to the
Nuclear Safety and Control Act and associated regulations, these facilities and activities may also be
required to comply with other regulatory instruments such as regulatory documents or standards.
CNSC regulatory documents are classified under the following categories and series:
1.0

Regulated facilities and activities

Series 1.1
1.2
1.3
1.4
1.5
1.6
2.0

Safety and control areas

Series 2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
2.14
3.0

Reactor facilities
Class IB facilities
Uranium mines and mills
Class II facilities
Certification of prescribed equipment
Nuclear substances and radiation devices

Management system
Human performance management
Operating performance
Safety analysis
Physical design
Fitness for service
Radiation protection
Conventional health and safety
Environmental protection
Emergency management and fire protection
Waste management
Security
Safeguards and non-proliferation
Packaging and transport

Other regulatory areas

Series 3.1
3.2
3.3
3.4
3.5
3.6

Reporting requirements
Public and Indigenous engagement
Financial guarantees
Commission proceedings
CNSC processes and practices
Glossary of CNSC terminology

Note: The regulatory document series may be adjusted periodically by the CNSC. Each regulatory
document series listed above may contain multiple regulatory documents. Visit the CNSC’s website forthe latest list of regulatory documents.

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