Design of electrical feedouts for hard-core components in nuclear power plants

Abstract

Hard-Core Components (HCCs) have become a key element in the defense-in-depth strategy for nuclear safety, particularly in scenarios involving extreme events such as seismic activity, fires, or total loss of power. This paper presents the conceptual design and qualification considerations for electrical feedouts—specifically, the penetrations that ensure the structural and functional integrity of power and signal transmission across containment barriers under severe conditions. The study emphasizes innovative design features such as bellows, service loops, and advanced fire barriers, which minimize the mechanical stress transmitted to containment walls and enhance system resilience. Through a combination of mechanical, thermal, and seismic design strategies, the proposed feedouts contribute to maintaining containment integrity and electrical functionality during beyond-design-basis events. This work constitutes a significant step forward in the development of reliable and qualified electrical penetrations as part of the HCC framework in modern nuclear facilities.