CSA N290.6-09 pdf download – Requirements for monitoring and display of nuclear power plant safety functions in the event of an accident.
N286 series of Standards: Note: The CSA N286 series of Standards has been superseded by CSA N286-05. However, because some Standards, Codes, and legislation still cite the requirements of these superseded Standards, they are referenced in N290.6. N286.0-92 (withdrawn) Overall quality assurance program requirements for nuclear power plants N286.1 -00 (withdrawn) Procurement quality assurance for nuclear power plants N286.2-00 (withdrawn) Design quality assurance for nuclear power plants N286.3-99 (withdrawn) Construction quality assurance for nuclear power plants N286.5-95 (withdrawn) Operations quality assurance for nuclear power plants N289 series of Standards: N289.1 -08 General requirements for seismic design and qualification of CANDU nuclear power plants CAN3-N289.2-M81 (R2008) Ground motion determination for seismic qualification of CANDU nuclear power plants CAN3-N289.3-M81 (R2008) Design procedures for seismic qualification of CANDU nuclear power plants CAN3-N289.4-M86 (R2008) Testing procedures for seismic qualification of CANDU nuclear power plants CAN/CSA-N289.5-M91 (R2008) Seismic instrumentation requirements for CANDU nuclear power plants N290 series of Standards: N290.1 3-05 Environmental qualification of equipment for CANDU nuclear power plants
3 Definitions
The following definitions apply in this Standard:
Accessible area — an area of a nuclear power plant, the normal environment of which is such that safe
access is allowed to authorized personnel during power production.
Authority having jurisdiction (AHJ) — the regulatory organization, office, or agency responsible for
approving or accepting design, equipment, materials, installation, or procedures according to applicable
Codes and Standards.
Availability — the fraction of time that a component or system is able to function. Availability can also
mean the probability that a component or system will be able to function at any time.
Buffer — the part of an instrumentation circuit that links different systems or components in such a way
that a fault in one system or component cannot affect the proper operation of the other system or
component.
Common-cause failure — a concurrent failure of two or more structures, systems, or components due
to a single specific event or cause, such as natural phenomena (earthquakes, tornadoes, floods, etc.),
design deficiency, manufacturing flaws, operation and maintenance errors, human-induced destructive
events, and others.
Note: This definition is taken from CNSC RD-337.
Cross-link failure — a failure that results in one or more devices in a system not functioning in their
intended manner.
Note: A cross-link failure is caused by
(a) an influence from within the system or from other systems (e.g., generated interference among redundant channels
that could not have been reasonably foreseen in the design process); or
(b) the consequential or causal influence of the initiating event itself (e.g., the effect of missiles generated by a
loss-of-coolant accident that could strike and damage post-accident monitoring and display equipment).
Design basis accident (DBA) — accident conditions for which a nuclear power plant is designed
according to established design criteria and for which damage to the fuel and the release of radioactive
material are kept within regulated limits.
Beyond design basis accident (BDBA) — accident conditions that are less frequent and more
severe than a design basis accident.
Note: A BDBA might or might not involve core degradation.
Functional independence — the property of a system that ensures that the operating characteristics of
the components making up the system are not influenced, beyond acceptable limits, by the normal or
abnormal behaviour of other systems.
Information chain — an arrangement of interconnected components that measures and displays a
variable.
Note: In the context of this Standard, an information chain might not be coincident with a special safety or process system
channel; however, this does not preclude the use of special safety or process system components for an information chain.
Isolation device — a component that functionally separates, in a defined manner, one part of a system
from other parts of the system or from other systems.
Main control room — the location from which the generating station is normally controlled.
Mission time — the period of time over which a system or piece of equipment is required to perform a
type of function to successfully meet its design requirements, following the initiation of a design basis
accident.
Note: Types of functions include active, passive, and not-fail.
Physical independence — the separation of the components of a system from other systems by a
suitable distance and/or by a suitable physical barrier.
Note: Physical independence generally provides protection against common-cause or cross-link failures. It can also assist in
the achievement of functional independence for some types of inter-system influences.
Plant characteristic — a distinguishing property of a nuclear power plant that can be measured or
inferred from monitored variables.
Note: Typical plant characteristics are reactivity, steam generator water inventory, reactor coolant temperature, and reactor
coolant pressure.CSA N290.6-09 pdf download.
