Retirement or Renewal? Decision-making processes for long-term operations of nuclear power plants

A large share of the world's nuclear fleet now operates near or beyond its original design lifetime, calling for making decisions about entering long-term operation (LTO). Remarkably, Nuclear Power Plants (NPPs) that face comparable technical and regulatory conditions often arrive at different outcomes: some enter LTO, while others are permanently shut down. Against this background, we formulated our research question: What are the factors shaping the decision-making process for NPP LTO? We addressed this gap through open interviews with senior utility and vendor leaders in the U.S. context, analyzed via the Gioia method and triangulated with relevant public documents. We identified several promoting and hindering factors for the LTO decision-making process overlooked in the literature, showing their different impact in regulated and deregulated markets. In particular, license renewal (LR) is routinely treated as a real option - a low-cost right rather than an obligation - used to reduce uncertainty while postponing life extension (LE) capital investments until revenue conditions are clearer. Indeed, LE costs are quite predictable while revenues remain uncertain and are fundamentally shaped by market design. Plants in U.S. deregulated markets face uncertain wholesale price cycles and policies, with pressures newly tempered by premium power purchase agreements from data center/AI loads and federal-state incentives in some cases. Human resources create delivery risk due to a lack of skilled workers, especially in temporary endeavours for LE projects. Of note, ageing management plays a key role from a techno-economic perspective, since it evolved from compliance to strategy, creating synergies with LE programs and power uprates. This article provides an option-based view of LR, identifies market design as a first-order moderator of LTO economics, and offers actionable guidance on timing, financing, workforce, and stakeholder engagement.