Dangers Of General Electric's Mark 1 Reactors Known For 40 Years (GE)

The New York Times reported this week that the Mark 1 nuclear reactors were developed in the 1960s by General Electric GE.

As far back as 1972, there were warnings that, if a Mark 1 reactor's cooling system failed, the fuel rods would overheat and, as a result, the primary containment vessel surrounding the reactor would burst, spilling radiation into the environment. That warning is dangerously close to becoming a premonition, with a containment vessel damaged at the Fukushima Daiichi nuclear plant in Japan.

Soon after GE began production of the Mark 1 reactors, American regulators began identifying weaknesses. Stephen H. Hanauer, then a safety official with the Atomic Energy Commission, said in 1972 that the Mark 1 system should be discontinued because, among other concerns, the smaller containment design is more susceptible to explosion and rupture from a buildup of hydrogen, which may be the case at Fukushima Daiichi.

Also in 1972, Joseph HenGdry, who later became the chairman of the Nuclear Regulatory Commission, said that while the idea of banning Mark 1 systems was attractive, it could also spell “the end of nuclear power” due to the fact that the technology had become so widely accepted.

In the wake of the disaster in Japan, these words now seem ironic, with David Lochbaum, director of the Nuclear Safety Program at the Union for Concerned Scientists, saying in an email on Tuesday that, “Not banning them might be the end of nuclear power.”

In the late 1980s, Mark 1 reactors in the United States were retrofitted with venting systems to help ease pressure in overheating situations, after Harold Denton, an official with the Nuclear Regulatory Committee, said that Mark 1 reactors had a 90 percent probability of bursting if the fuel rods were to overheat and melt in an accident.

It is not known what, if any, modifications were made to the failing Mark 1 reactors in Japan, but the ongoing threat of radiation to the country's population is sure to raise the question of why 40-year-old warnings were all but ignored.