A local nuclear engineer who is also a UMass-Lowell professor said this week that the situation with the damaged nuclear plants on the East Coast of Japan is changing so fast it's hard to know exactly what's happening or how it will end.
"It's a dynamic situation," Dr. Gilbert Brown said Monday afternoon. He noted then that it appeared the nuclear power plants damaged by the earthquake and ensuing tsunami had been stabilized by workers on the ground pumping in seawater to cool down the radioactive fuel rods.
He said then that it appeared power company employees had stemmed a full-blown meltdown.
But all that changed Monday night, when there was a third explosion in one reactor followed by a fire at another reactor at the 40-year-old General Electric model Fukushima I Nuclear Power Station.
It appears now that the fuel rods may have experienced some melting, meaning that a meltdown is, indeed, in progress.
The question, Brown said yesterday, is how far it will go and what will happen if there is a full meltdown.
"It's still a challenge for the guys trying to keep water in the vessel and keep the containment building intact," Brown said. "It's obvious there's been a lot of fuel damaged."
In addition, varying amounts of radiation have been detected in and around the power plant, while the evacuation zone has been expanded. As of 1:30 p.m. Eastern Standard Time, Japanese government officials were ordering everyone within 12.5 miles of the plant to leave immediately, while those within 20 miles were ordered to stay indoors to reduce exposure to radiation. But many people are simply fleeing the area, according to news reports from the scene.
Low levels of radiation have been detected in Tokyo, 150 miles south of the plant, as well as at a U.S. military base south of Tokyo. Some 700 nuclear plant workers have been pulled from the site, although about 50 remained behind.