The progenitor of the BWR line was the 5 MW Vallecitos Boiling Water Reactor (VBWR), brought online in October 1957.
The design garnered world attention in the aftermath of the INES level 7 Fukushima Daiichi nuclear disaster of 11 March 2011.
After the plant became severely damaged in the Tōhoku earthquake and tsunami, loss of reactor core cooling led to three nuclear meltdowns, three hydrogen explosions, and the release of radioactive contamination in Units 1, 2 and 3 between 12 and 15 March.
A reactor after a full-power shutdown may require active cooling of decay heat from long-lived radioactive isotopes for a year or more.
The progenitor of the BWR line was the 5 MW Vallecitos Boiling Water Reactor (VBWR), brought online in October 1957.