Draft Details

Designation:CSA N285.4
Contact name:Robert Reipas
Review start date:Mar 8, 2023
Review end date:May 7, 2023
Contact email:thuy.ton(at)csagroup.org
Draft Scope/Description:


This Standard defines requirements for the periodic inspection of pressure retaining systems, components, and supports that form part of a CANDU nuclear power plant.

Periodic inspection (see Annex A for additional guidance) is considered to include the fluid boundary portions of components and piping, including their supports that comprise

a) systems containing fluid that directly transports heat from nuclear fuel and other systems whose failure can result in a significant release of radioactive substance;

b) systems essential for the safe shutdown of the reactor or the safe cooling of the fuel, or both, in the event of a process system failure; and

c) other systems or components whose failure could jeopardize the integrity of the systems described in Item a) or b), or both.

In addition, for components exposed to conditions beyond the known experience base, and where such components constitute part of a vital system, the components may be considered suitable for inclusion in the periodic inspection program, as supplementary periodic inspections.


This Standard addresses

a) failure aspects;

b) classification of areas subject to periodic inspection;

c) provision for access;

d) examination methods and procedures;

e) personnel qualifications;

f) frequency of periodic inspection;

g) responsibilities;

h) documentation;

i) records;

j) evaluation of periodic inspection results;

k) dispositioning; and

l) repair, replacement, and modification requirements.


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 (nonmandatory) to define their application.

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