Fukushima: Mark 1 Nuclear Reactor Design Caused GE Scientist To Quit In Protest 35 Years Ago

[Shallah Kali]

http://abcnews.go.com/Blotter/fukushima-mark-nuclear-reactor-design-caused-ge-scientist/story?id=13141287

Thirty-five years ago, Dale G. Bridenbaugh and two of his colleagues at General Electric resigned from their jobs after becoming increasingly convinced that the nuclear reactor design they were reviewing -- the Mark 1 -- was so flawed it could lead to a devastating accident.

Questions persisted for decades about the ability of the Mark 1 to handle the immense pressures that would result if the reactor lost cooling power, and today that design is being put to the ultimate test in Japan. Five of the six reactors at the Fukushima Daiichi plant, which has been wracked since Friday's earthquake with explosions and radiation leaks, are Mark 1s.

"The problems we identified in 1975 were that, in doing the design of the containment, they did not take into account the dynamic loads that could be experienced with a loss of coolant," Bridenbaugh told ABC News in an interview. "The impact loads the containment would receive by this very rapid release of energy could tear the containment apart and create an uncontrolled release."

The situation on the ground at the Fukushima Daiichi plant is so fluid, and the details of what is unfolding are so murky, that it may be days or even weeks before anyone knows how the Mark 1 containment system performed in the face of a devastating combination of natural disasters.

[Skip_In_Boulder]

1. I heard someone on the radio today saying there are 36 of these

Mark 1 reactors in the U.S. The best link I can find right now is this one from the Nuclear Energy Institute which if I count them correctly are 29.

6. How many U.S. reactors use the Mark I containment design used at Fukushima Daiichi Unit 1?

Six U.S. nuclear reactors (Monticello in Minnesota, Pilgrim in Massachusetts, Dresden 2 and 3 and Quad Cities 1 and 2 in Illinois) are the same base design as the Fukushima Daiichi Unit 1 design (BWR-3 design with Mark I containment). Twenty-three U.S. nuclear plants are boiling water reactors (either BWR-2, BWR-3 or BWR-4) and use the Mark I containment: Browns Ferry 1, 2 and 3; Brunswick 1 and 2; Cooper; Dresden 2 and 3; Duane Arnold; Hatch 1 and 2; Fermi; Hope Creek; Fitzpatrick; Monticello; Nine Mile Point 1; Oyster Creek; Peach Bottom 2 and 3; Pilgrim; Quad Cities 1 and 2; Vermont Yankee. Although these are the same basic reactor design, specific elements of the safety systems will vary based on the requirements of the U.S. NRC.

http://www.nei.org/resourcesandstats/documentlibrary/newplants/factsheet/faq---japanese-nuclear-energy-situation/?page=3