NUCLEAR’S NEXT CHAPTER | COVER STORY


as European energy security concerns intensified, but extending the license was the easy part. The harder challenge was confronting the reality that much of the plant’s electrical switchgear had become obsolete, with spare parts increasingly unavailable and maintenance progressively more difficult. ENGIE’s Belgian subsidiary Electrabel thus brought in an ABB Electrification Service team for a rigorous, consultative assessment of the entire installed base. Their role was to assess how to ensure the plant’s electrical infrastructure could support another decade of safe, reliable operation and to determine what a sustainable path to get there actually looks like.


The case against ripping and replacing The answer, more often than not, is not to tear everything out and start over. That instinct, the clean-slate impulse, is understandable, but it is usually wrong for nuclear, because full replacement of electrical systems in an operating plant means extended shutdowns, cascading redesign of cabling and civil structures, requalification of every interface, and costs that can spiral well beyond any reasonable business case. In a plant providing baseload power to a national grid, prolonged downtime fast becomes a strategic vulnerability. At Doel 4, a targeted approach was executed: six


switchboards were retrofitted with new circuit breakers, three replaced entirely with new units, and a total of 76 circuit breakers swapped out using the latest vacuum interruption technology. The intervention was deliberately surgical. Retrofit where the existing infrastructure could support it, replace only where obsolescence or safety demanded it. The results speak to a principle the nuclear industry would do well to embrace more broadly: more than half of the electrical equipment in a typical installation (the metal cabinets, steel plates, busbars) can continue to serve reliably for extended periods if the active components inside them are modernised, properly monitored, and maintained. Fundamentally, this is sound engineering which carries benefits that extend well beyond cost. It supports the circular economy by keeping materials in use and reducing resource dependency, it minimises downtime and disruption, and it addresses the very real spatial constraints of working inside a facility designed decades ago with no thought of future reconfiguration. Doel is far from an isolated case. In Canada, Bruce


Power, one of the world’s largest operating nuclear generating stations, selected ABB to supply advanced excitation technology to help extend the life, reliability, and efficiency of eight generating units, drawing on UNITROL systems that reflect close to five decades of experience in the nuclear sector. In both projects, the underlying philosophy is identical: extend the productive life of critical assets through targeted, intelligent modernisation rather than wholesale replacement.


Why data matters more than hardware Like many other industries, the evolution of service for nuclear plants is increasingly becoming about data, too. Nuclear environments impose unique constraints that few other industries face. Access is restricted, radiation exposure must be strictly minimised, inspection


At Doel 4 a targeted approach was executed using retrofit where the existing infrastructure could support it and replacement only where necessary. Source: Tractebel


windows are narrow, and regulatory oversight is rightly unrelenting. Traditionally, all of this has meant conservative, time-based maintenance schedules, replacing components at fixed intervals regardless of their actual condition, because the consequences of an unexpected failure are simply unacceptable. For decades, this approach was the best available option. But as plants age, it is an approach that is becoming


increasingly inadequate. Components degrade at different rates depending on operating conditions, load profiles, and environmental factors, which means that treating every asset as if it ages on the same schedule leads to unnecessary replacements on one hand and undetected degradation on the other. Neither outcome is acceptable. Digital monitoring of electrical assets, tracking health,


performance, and energy efficiency in real time, allows operators to shift from calendar-based replacement to condition-based intervention. You service what needs servicing, when it needs it, with full visibility into degradation trends and failure probabilities. The result is better uptime, lower lifetime costs, and higher safety margins. Remote inspection technology is pushing this


transition further still. In radiologically controlled areas, where human access is inherently limited and every minute of exposure matters, automated systems can perform inspections, collect condition data, and assess equipment states without putting workers at unnecessary risk. These capabilities are already in use at a growing number of facilities, and they are advancing rapidly. As the global fleet ages and the regulatory bar continues to rise, demand for non- intrusive, data-rich assessment will only intensify.


Building for the engineer of 2060 If a plant is going to operate for 80 or 100 years, its electrical and control infrastructure will almost certainly need to be modernised multiple times over that lifespan. The instrumentation and control systems installed today will eventually become the legacy systems of 2060; the switchgear qualified now will need to be reassessed by the mid-2040s; the digital platforms deployed now will require capabilities that cannot yet be fully anticipated. This means the first modernisation must be designed with the second and third ones already in mind. Architectures should be open, modular, and capable of


www.neimagazine.com | May 2026 | 17


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