ISO DIS 18195

Description / Abstract: This International Standard is intended to provide a new methodology to Nuclear Power Plant (NPP) designers, fire safety professionals and nuclear safety authorities. This methodology aims to verify the adequacy of the performance of fire barriers in nuclear power plants in order to avoid fire propagation. This method is a potential tool for risk-informed, performance-based assessment.

This method is based on the EPRESSI method developed by EDF in collaboration with Efectis France fire safety laboratory in France for EPR reactors [1].

The document provides:

- Guidelines for determining the thermal effects to consider on fire barriers inside a given room

- Guidelines for determining the global performance of the fire barriers based on standard test characterization

- Guidelines for assessing the need for additional tests to verify the robustness of the solution

Requirements of applicable standards, numerical tools validation and verification (VV), and the expected qualification of fire resistance laboratories are detailed.

The limitations of the method’s applicability and scope are discussed.

The purpose and justification of this International Standard is to describe a new methodology for the verification of the efficiency of fire barriers, which is initially based on a standardized fire resistance test.

The significance of this work relates to the fact that the present methodology will enhance the level of safety by providing more realism to hazards analysis in combination with standardized test data. It completes the standard ISO-fire rating required for justifying the performance.

Maybe the most relevant benefit of this method concerns the determination of the global performance of a barrier in a fire of extended duration compared to the classification given by the ISO-fire rating.