Probabilistic safety assessment for nuclear power plants
|Publication Date:||1 January 2017|
Reactors and other potential sources
This standard provides the requirements and guidance for the preparation and maintenance of a PSA at a water-cooled NPP. The radiation sources of concern include both
a) water-cooled power reactors; and
b) other potential sources of radioactive releases to the environment.
1) This Standard may be used to provide guidance for nuclear facilities other than NPPs.
2) "Other potential sources" include, for example, wet storage bays and dry used fuel storage facilities.
3) Systems that only contain radiation during post-accident conditions (eg, ECI recovery), are not considered in the identification of radiation sources. The source of radiation of those systems is the reactor, which is considered already as a source.
New and existing reactors
This Standard applies to both new and existing water-cooled NPPs.
1) "Existing NPPs" refers to NPPs initially licensed before 2017.
2) "New NPPs" refers to NPPs initially licensed after 2016.
3) The requirements for a new NPP might be different than the requirements for an existing NPP. This Standard notes where the requirements might be different.
Single and multi-reactor facilities
This Standard applies to NPPs with one or more water-cooled power reactors.
1) The requirements for a single-reactor NPP might be different than the requirements for a multi-reactor NPP. This Standard notes where the requirements might be different.
2) Provisions related to the risk aggregation and whole-site PSA are provided in Clauses 13 and Annex I.
Level 1 PSA and Level 2 PSA
This Standard addresses both Level 1 PSA and Level 2 PSA.
This Standard applies to both specific PSAs and whole-site PSAs.
1) A specific PSA might assess only a single hazard for a single source at a NPP. A whole-site PSA assesses all sources and all hazards.
2) Some parts of this Standard apply only to specific PSAs. For example, Annexes C to H apply only to specific hazards for power reactors. This Standard notes where requirements apply only to specific PSAs.
This Standard does not address and does not apply to malevolent acts.
Note: In Canada, malevolent acts are addressed separately under the CNSC Nuclear Security Regulations.
In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the standard.
Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.
Notes to tables and figures are considered part of the table or figure and may be written as requirements.
Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.
In this Standard, "shall be considered" or "shall consider" means that the user evaluates the impact and documents any decisions.