Berkeley nuclear engineers say the Fukushima Daiichi power plant, which is now shut down, is about 40 years old.
The 8.9 earthquake caused the reactor to leak radiation in a way that they say they could not have anticipated and caused evacuations of 50,000 people, within six miles of the plant. Japanese engineers are now concerned about cooling the reactor and avoiding more leaks.
"The reactor is guarded by multiple barriers, so this time apparently some of the barriers were broken, but we still have barriers in the system," said Ahn.
He says that's the reason the radioactivity has so far been confined to the control room and not the atmosphere. At this point, Japanese engineers are trying to safely cool the reactor down by first releasing steam which contains some low levels of radioactivity and then slowly pouring coolant into the system.
"They have to do it within a few days at most. So within, maybe over this weekend well see some major results," said Ahn.