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

satisfactory; see safety performance rating methodology

Any deliberate act or omission, directed against a nuclear facility or nuclear substances, that:

1. endangers or is likely to endanger the health and safety of any person; or
2. results or is likely to result in contamination of the environment.

(Source: Nuclear Security Regulations )

source axis distance

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 this stage is subject to all safeguards procedures specified in the Safeguards Agreement. In Canada, this is also called Group 1 nuclear material.

A verification system that is established in accordance with a safeguards agreement. (Sources: General Nuclear Safety and Control Regulations ; Class I Nuclear Facilities Regulations )

Means

1. the IAEA Agreement and any arrangement between Canada and the IAEA made under that agreement; and
2. any agreement to which Canada is a party for the establishment in Canada of a verification system in respect of nuclear substances, prescribed equipment or prescribed information, and any arrangements made under such an agreement.

(Sources: General Nuclear Safety and Control Regulations ; Class I Nuclear Facilities Regulations )

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.

Equipment that is used in accordance with a safeguards agreement. (Source: General Nuclear Safety and Control Regulations )

The set of limits and conditions within which a nuclear power plant must be operated to ensure compliance with the safety analysis upon which the reactor operation is licensed and that can be monitored by or on behalf of the operator and can be controlled by the operator. See also operational limits and conditions.

A state in which a facility is not operational and the fundamental safety functions can be ensured and maintained 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.

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 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 the overall nuclear facility design is capable of meeting specified acceptance criteria.

Activities to plan, execute, verify and document safety analyses; to identify and act upon research and experience; to train analysts; and to preserve knowledge. The safety analysis program includes interfaces with other programs to ensure that a safety analysis.

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 associated with the conduct of a proposed activity or facility and considers the effectiveness of preventive measures and strategies in reducing the effects of such hazards. This SCA is one of the 14 within the CNSC SCA Framework.

A technical topic used by the CNSC to assess, review, verify and report on regulatory requirements and performance across all regulated facilities and activities. The SCAs cover:

• 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

An assessment of all aspects relevant to safety of the siting, design, construction, commissioning, operation or decommissioning of a nuclear facility.

An integrated collection of arguments and evidence to demonstrate the safety of a facility and the meeting of 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.

With respect to fitness for duty, a position certified or authorized by the CNSC that requires workers to make decisions and take actions that have a direct and immediate impact on nuclear safety and security of a high-security site.

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.

A periodic evaluation of safety culture using a defined framework and method for data collection, analysis, interpretation and reporting.

A specific purpose that a structure, system or component must accomplish for safety, including those functions necessary to prevent accident conditions and to mitigate their consequences.

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, a nuclear power plant’s probabilistic safety goals can be expressed in terms of frequency of severe core damage or of radionuclide releases.

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 occurrences and design-basis accidents are not exceeded. The safety group may include certain safety and safety support systems and any interacting process system.

Measures taken that result in more effective implementation of the safety objectives of a nuclear power plant.

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 of doses or risks for comparison with criteria, or of other quantities (such as concentrations or fluxes of radionuclides or hazardous substances) that are considered to more reliably indicate impact and which can be compared with protective limits set by legislation or regulation.

Limits on operational parameters within which a nuclear facility has been shown to be safe.

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 to radiological releases.

Data that is sensitive to and/or signals changes in the safety performance of systems or programs that maintain the licensing basis of a nuclear facility.

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 progress on 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 compliance within 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 are promptly 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 marginally ineffective. 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 a high 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.

Observable attributes of safety that reflect an organization’s safety-related values and behaviours that each worker is expected to exhibit consistently on the job.

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 accordance with 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 under normal 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 that can 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 with the 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., through flooding or mechanical damage).

See also systems important to safety.

A position that has a role in the operation of a high-security site, where impaired performance could result in a significant incident affecting the environment, the public, the health and safety of workers and others at 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 high-security site.

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, a situation, 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 public

A system designed to support the operation of one or more safety systems.

A system provided to ensure the safe shutdown of a nuclear reactor or the residual heat removal from the core, or to limit the consequences of anticipated operational occurrences and design-basis accidents.

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.

See severe accident management (SAM) program.

severe accident management guidelines; see severe accident management (SAM) program

See systematic approach to training.

See safety performance rating methodology.

See station blackout.

See safety and control area.

See scatter radiation.

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.

severe core damage frequency

Has the meaning assigned by the definition “surface contaminated object (SCO)” in the IAEA Regulations. (Source: Packaging and Transport of Nuclear Substances Regulations, 2015 )

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 high level whether the model sensitivity to changes in input values is realistic.

See secondary control room.

See thyroid screening.

shutdown

shutdown cooling system

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 the conditions 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 )

Means a sealed source that is designed to be used in an exposure device, and includes the components that are permanently attached to the sealed source. (Source: Nuclear Substances and Radiation Devices Regulations )

A room where operations personnel can monitor the safety of a reactor facility and execute basic safety functions to maintain or place the reactor facility in a safe state following any incident that renders the main control room unavailable.

The system that transports heat from the primary heat transport system to the ultimate heat sink. See also primary side.

See primary and backup (secondary) trip parameter.

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, the exposure container need not be locked.

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.

An interview conducted by a qualified investigator representing a licensee, in which information is collected to confirm or deny adverse information.

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.

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.

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 rise in the water of a harbor or a lake, whether or not it is oscillatory.

The person in a nuclear facility who is responsible for interpreting the regulations, policies and procedures that apply to radiation protection and for providing procedure-related approvals where required. Also called authorized health physicist; responsible health physicist.

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, the process of assessing the impact that a variation in the probability of an event or a change in a modelling assumption would have on the probabilistic safety assessment results.

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 the date 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 is classified as a fatality, not as a serious injury.

With respect to CANDU reactor facilities, a failure that leads or that could lead, in the absence of action by any special safety system, to significant fuel damage or a significant release from the CANDU reactor facility.

The period from initial operation to final withdrawal from service of a structure, system or component.

In respect of radiation devices, means any maintenance of a device, including installation, repair or dismantling, other than maintenance that

1. constitutes routine operating procedures as indicated in the manufacturer’s operating manual for the device; or
2. 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

1. as indicated in the manufacturer’s operating manual for the equipment; or
2. 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 as servicing.

The possession of radiation devices for the purpose of servicing, installation or dismantling. The term is used as a licence use type.

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.

An accident more severe than a design-basis accident and involving severe fuel degradation in the reactor core or irradiated fuel storage.

See severe accident management (SAM) program.

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

steam generator emergency cooling system

See plant shift supervisor.

See plant shift supervisor.

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.

With respect to nuclear material accounting, the difference between the quantities of nuclear material in a batch, as stated by the shipping material balance area (MBA) and as measured at the receiving MBA.

See senior health physicist.

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.

One of a set of neutron-absorbing rods that are inserted into a reactor core when needed to stop (shut off or shut down) the nuclear reactor.

A system inside a radiation device, between the shielded and unshielded position of the sealed source, that may be operated manually, electrically or pneumatically.

The inability to provide a urine sample as a result of a physiological or psychological medical condition.

The inability to provide a sufficient amount or volume of breath to permit a valid alcohol test as a result of a physiological or psychological medical condition.

International System of Units (Système international d’unités)

In the context of certification of radiation devices or Class II prescribed equipment, a change in the equipment’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 machine used as an irradiator)
• a change or upgrade of software that allows the machine to work in a different mode or energy level outside 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 the certificate, or significant changes to device labelling – it is important for the machine to be identifiable in the field

The International System of Units (SI) unit of equivalent dose and effective dose, equal to 1 joule/kilogram.

An event or situation that brought the fuel (>1%) outside of its fitness for service limits.

A release of radioactive material that results in an effective dose, received by or committed to a typical member of the critical group, in excess of 0.5 millisievert.

A person designated by the applicant authority to act on behalf of the applicant in communications with the CNSC.

See administrative (nuclear) criticality safety control.

See full scope simulator.

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.

The criterion used to determine whether a system is capable of performing its function as per design in the presence of a single failure.

See systems important to safety.

See systems important to safety.

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.

OR

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 to conversion, 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 for the 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 the International Atomic Energy Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons  [11].

The distinguishing characteristics, qualities, physical features and environment of the piece of land on which a nuclear facility or activity is located.

The processes and methodologies used to determine whether the characteristics of a site and the surrounding region are appropriate for the construction, operation and future decommissioning and abandonment of a nuclear facility regulated under the Nuclear Safety and Control Act.

All persons working on the site of a nuclear facility, either permanently or temporarily.

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.

The process of selecting a suitable site for a facility, including appropriate assessment and definition of the related design bases.

Conditions, circumstances or configurations that occur, are discovered or that may lead to an event. This definition applies to event reporting.

A mental and/or physical activity that requires a measurable degree of proficiency. The terms “skill” and “ability” are often used interchangeably.

The layer of cells within the skin that are 7 mg/cm² below the surface. (Source: Radiation Protection Regulations )

The secondary impact resulting from a package initially impacting on a corner or an edge.

The difference between the amount of sleep an individual needs and the amount of sleep that the individual actually obtains.

shift manager; see plant shift supervisor

See reactor facility.

See reactor facility.

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.

scheduled maintenance release

OR

See security monitoring room.

OR

small modular reactor (see reactor facility)

spent nuclear fuel; see used nuclear fuel

See safe operating envelope.

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 system or
• to compensate for excess reactivity in the reactor core during operation or when the reactor is shut down

With respect to nuclear criticality safety, liquid containing dissolved material or a suspension of that material in the liquid. This includes aqueous (water-based) solutions but excludes those where the hydrogen is replaced by either deuterium or tritium.

See shutoff rod.

A radiation-induced health effect that occurs in the exposed person.

An apparatus used to store, transport and exchange sealed source assemblies for use in exposure devices.

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 the relationship between plutonium produced and power generated. See also batch data.

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 be dismantled for replacement of the sealed source.

The following source materials in any form, including ore, concentrate, compound, metal or alloy, or incorporated in any substance, other than medicinals, and in which the concentration of source material is greater than 0.05 weight %:

1. uranium that contains the mixture of isotopes that occurs in nature;
2. uranium that is depleted in the isotope 235; and
3. thorium.

Note: [The list above] does not include:

1. source material occurring as contaminants in laundry, packaging, shielding or equipment; or
2. depleted uranium used as shielding for Class II prescribed equipment, within the meaning of section 1 of the Class II Nuclear Facilities and Prescribed Equipment Regulations , for radiation devices or for transport 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.

See exposure head.

The amount and isotopic composition of material released (or postulated to be released) from a nuclear facility.

The act of flowing air, gas or steam through liquid in a vessel.

See non‑routine bioassay.

[A]s follows:

1. plutonium and all isotopes, alloys and compounds and any material that contains any of these substances; and
2. 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

1. special fissionable material occurring as contaminants in laundry, packaging, shielding or equipment;
2. special fissionable material used as a sensing component in instruments in quantities of four effective grams or less; or
3. 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.

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

Note: This material takes the form of an indispersible solid radioactive material or a sealed capsule containing 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.

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.

Includes prohibited and restricted firearms, items and devices that a licensee can only acquire under the authority of the CNSC acting as a public service agency under the Public Agents Firearms Regulations made under the Firearms Act.

See mineralized waste rock.

See technical assessment.

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 )

See used nuclear fuel.

See wet storage bay.

See used nuclear fuel.

See safety performance indicator.

See safety-related systems.

shift supervisor; see plant shift supervisor

See structures, systems and components.

See systems important to safety.

source skin distance

See safe shutdown state.

site selection threat and risk assessment

Any person or group that has an interest in, is affected by, or has an effect on an environment in which a licensed 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 under consideration. 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.

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 a certificate that gives the results of the characterization.

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).

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 fuel cycle, is imported into Canada

Note: The IAEA safeguards in the agreement do not apply to material in mining or ore processing activities.

A complete loss of alternating current (AC) power from offsite and onsite main generator, standby and emergency 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.

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.

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.

A radiation-induced health effect, the probability of occurrence of which is greater for a higher radiation dose and the severity of which (if it occurs) is independent of dose. Note: Stochastic effects may be somatic effects or hereditary effects, and generally occur without a threshold level of dose. Examples include cancer and leukemia.

With respect to nuclear substances and radiation devices, possession for storage only.

With respect to nuclear criticality safety, a regular arrangement of storage cells.

See wet storage bay.

With respect to nuclear criticality safety, a volume having defined boundaries within which a storage unit is positioned.

See wet storage bay.

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.

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.

An abnormal rise in water level accompanying a hurricane or other intense storm.

With respect to nuclear material accounting, a grouping of items and/or batches having similar physical and chemical characteristics. For example, items may be grouped according to isotopic composition in order to facilitate statistical sampling.

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.

A general term encompassing all of the elements of a facility or activity that contribute to protection and safety. 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 a discrete element of a system. Some examples are wires, transistors, integrated circuits, motors, relays, solenoids, pipes, fittings, pumps, tanks and valves.

See systems important to safety.

See exposure device source path.

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 in its derivation but not for contingencies such as double batching or inaccuracies in analytical determinations.

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.

A criterion for a structure, system or component that designates the minimum functional capability and performance levels required for effectiveness.

Periodic sequences of eight-hour day shifts that are built into a shift worker’s schedule.

Equipment and instruments that are not installed as part of the original plant design, but are used as an additional 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).

With respect to maintenance of nuclear facilities, activities carried out to confirm compliance with the safe 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 or other items, and any interference with containment or tampering with IAEA equipment, samples and data. See also International Atomic Energy Agency inspector.

An item that is suspected to be counterfeit, fraudulent or substandard.

The capacity of a thing, action, activity, or process to be maintained indefinitely. (Source: Federal Sustainable Development Act)

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)

See sievert.

A structured approach to training, composed of the following phases:

• analysis: identification of training needs and of the knowledge, skills and attributes required to perform a particular job
• design: conversion of the knowledge, skill and attribute requirements identified in the analysis into training 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 effectiveness

Fuel that had no known defect prior to an event, but that fails or exceeds the fuel integrity criteria defined in the version-controlled document or in the licensee documents requiring notification of change as a result of the event.

A review in which specified and appropriate methods are used to identify, appraise and summarize studies addressing a defined question.

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 sequence and that have the most significant impact in reducing the possibility of damage to fuel, associated release of radionuclides or both.