PTAN 2018 Retention of materials

OBJECTIVES OF THE GUIDE

The modification of the order of 30 December 2015 [1] on nuclear pressure equipment introduces, in article 8-1, a new requirement relating to the retention of material from the components* of N1 NPE, in particular those with a high risk of heterogeneity and of certain permanent assemblies between components* of this type.
This requirement was drafted following several recent deviations encountered on components* of reactor vessels and SGs already installed or being manufactured and for which an assessment was rendered difficult due to the lack of sufficient representative material concerning them. This requirement is not an ESR.

The purpose of this guide is to define the principles to be applied by the equipment manufacturer and material manufacturers for the retention of this material, until its transmission to the Operator.
This guide is structured as follows:

• identification of components and permanent assemblies for which the material retention requirement applies (§ 5),
• principles of retention to deploy at the material and equipment manufacturers’:
  • § 6 for mass-produced components,
  • § 7 for sacrificial parts,
  • § 8 for permanent assemblies,
• additional provisions (§ 9).

Two functional diagrams of the component and permanent assembly parts recoverable for material retention are provided in appendix 1.
Any deviation from the application of this guide must be explained and justified by the material or
equipment manufacturer and submitted for approval to the Operator.


[1] Ministerial order of 30 December 2015 on nuclear pressure equipment, amended.