As the March 2011 reactor meltdowns at Tokyo Electric Power Co.'s Fukushima No. 1 power plant demonstrated, loss of power sources for an extended period of time at a nuclear power plant — known as a "station blackout" (SBO) — can lead to catastrophic results. It was recently reported that the Nuclear Safety Commission colluded with Tepco over the nation's SBO-related safety standard about two decades ago.
This revelation and the recent government decision to restart the Nos. 3 and 4 reactors at Kansai Electric Power Co.'s Oi nuclear power plant in Fukui Prefecture only serve to reinforce the widespread belief that the government is continuing to protect the interests of the nuclear power industry even in the wake of the Fukushima disaster.
In 1990, the government issued a safety standard stating that there is no need to take into account SBOs lasting 30 minutes or longer in designing a nuclear power plant. Because preparations for long SBOs had become obligatory overseas, in 1991 the NSC established a working group to consider a revision of the safety standard. The group consisted of five experts and officials from Tepco, Kepco and the then Japan Atomic Energy Research Institute, which had a cooperative relationship with the power companies.