IEEE P344/D27

IEEE P344/D27 is an approved IEEE draft recommended practice focused on seismic qualification of Class 1E equipment for nuclear power generating stations. It addresses how safety-related electrical and control equipment may be evaluated for earthquake resistance, helping engineers and purchasers understand expected performance under seismic conditions. As an inactive draft later replaced by 344-2004, it remains a useful reference for nuclear engineering teams working with legacy qualification records, design reviews, and technical documentation.

About IEEE P344/D27

This technical document provides guidance for qualifying Class 1E equipment intended to support nuclear plant safety functions during and after seismic events. IEEE P344/D27 is centered on recommended practice rather than a product specification, so its value lies in the qualification approach, test expectations, and engineering judgment used to assess equipment capability. In the nuclear power context, that can include how equipment is selected, analyzed, tested, and documented to demonstrate seismic robustness consistent with safety requirements.

Where is IEEE P344/D27 used?

IEEE P344/D27 is typically used in nuclear power generating stations where safety-related systems must remain functional after earthquake loading. It is relevant to Class 1E equipment such as control devices, protective relays, instrumentation, and related electrical assemblies that support plant safety functions. The standard may also be used during procurement, qualification testing, and design verification activities when engineers need a common basis for evaluating seismic performance and maintaining traceable technical records for nuclear engineering applications.

Importance in practice

In practice, IEEE P344/D27 helps reduce uncertainty in seismic qualification by giving stakeholders a shared framework for assessment and documentation. That matters for compliance reviews, equipment acceptance, and long-term plant reliability, especially when safety systems must be defended against seismic risk. Using a consistent recommended practice can support clearer procurement language, more repeatable testing, and better design control. For organizations handling legacy nuclear equipment, IEEE P344/D27 can also help interpret older qualification evidence against recognized engineering expectations.

• Seismic qualification for Class 1E equipment
• Recommended practice for nuclear power stations
• Safety-related design and test review
• Legacy reference; replaced by 344-2004