The New York Times reports today that the reactor design used in Japan's Fukushima Daiichi plant -- as well as in 16 other nuclear plants in the U.S. -- has been dogged by safety concerns for decades.
The G.E. Mark 1 reactors use a weaker containment vessel than other types of reactors, the Times reports -- making them cheaper, but also at potentially higher risk of failure. Safety officials, as early as the 1970s, were raising alarms about the potential for an explosion and rupture in the containment units from a buildup of hydrogen.
Of the 16 plants in the U.S. that use the Mark 1 containment system, six are in the Midwest:
For their part, G.E. defends the reactor design, telling the Times "there has never been a breach of a Mark 1 containment system."
UPDATE: Reuters interviewed a G.E. engineer, who said he resigned 35 years ago over concerns about the safety of the Mark 1 containment system.