How the Fukushima Daiichi Accident Changed (or not) the Nuclear Safety Fundamentals?

Abstract

In this chapter, the fundamentals of nuclear safety that the Fukushima Daiichi accident did and did not change will be discussed. While the most basic strategy of defense-in-depth principle is still valid, some problems have emerged after Fukushima, preparedness for all-hazards and multiple disasters, and importance of the administration of emergency response. From this observation, enhancing the resilience of nuclear systems is a critical issue after Fukushima. The safety enhancement measures considered in nuclear facilities will be reviewed referring to the elementary characteristics of systems resilience, and a new framework will be proposed for dealing with unsafe events, where unsafe events are classified into three categories.

Hybrid Disasters—Hybrid Knowledge

“…These studies have tackled questions coming from very different disciplinary fields, from the physical, engineering, social, and political sciences to the humanities, using multiple methodological approaches anchored in diverse epistemologies within academia [17,39], (Guarnieri, Sato, Pecaud, this issue), and beyond when engaging with the more operational level of technical expertise [40,41], this volume) and policy-making [42,43].…”

Optimization and performance of metafoundations for seismic isolation of small modular reactors

“…This sequence of events triggered the Fukushima Dai‐ichi disaster with the hydrogen explosion in the reactor buildings—Unit #1 and #3—and around the torus—Unit #2—due to insufficient cooling provided by the emergency diesel generators caused by a lack of power supply (IAEA, 2016; Synolakis & Kânoğlu, 2018). As a result, the damage at the Fukushima NPP entailed intensive research and engineering efforts to include safe shutdown earthquakes (SSEs), not foreseen in the original design (Furuta & Kanno, 2017; Park & Seol, 2016). This justifies the need to consider other earthquake levels stronger than those used in the SSE, that is, 0.3 g, at least at the simulation level.…”

Seismic assessment of small modular reactors: NuScale case study for the 8.8 Mw earthquake in Chile

“…Fukushima's disaster outcomes have led to intensive research and engineering efforts to include beyond design-basis accidents not considered in original constructions or projects [3][4][5][6][7]. Several key issues have been also identified in both the actual safety culture in the nuclear industry [8][9][10] and limitations to the actual severe accidents management strategies [11][12][13].…”