After 500 days, Fukushima Reactors Still Spewing Deadly Radiation by DiaNuke.org

TAKASHI SUGIMOTO | Asahi Shimbun

A little more than 500 days after the accident at the Fukushima No. 1 nuclear plant threatened to force the evacuation of the entire Tokyo metropolitan area, the situation is certainly much improved.

The levels of cesium being emitted from the damaged reactors have dropped substantially, core temperatures in the pressure vessels are being kept within targeted levels, and the plant operator has started removing unused nuclear fuel assemblies as an experiment.

However, workers still must overcome a number of issues to make progress toward decommissioning the reactors at the plant, such as dealing with leaking contaminated cooling water, determining the state of the pressure vessels and removing melted nuclear fuel from the reactor cores.

Photo taken from a Kyodo News helicopter on July 18, 2012, shows the wrecked building housing the No. 4 reactor of the Fukushima Daiichi Nuclear Power Station in Fukushima Prefecture. The Tokyo Electric Power Co. removed the same day an unused nuclear fuel assembly from a spent fuel pool at the No. 4 reactor to check the extent of damage to the stored fuel ahead of the start of full removal work planned for next year. (Kyodo)

RADIOACTIVE MATERIALS

According to calculations by Tokyo Electric Power Co., the operator of the Fukushima No. 1 plant, a total of about 10 million becquerels per hour of radioactive cesium was being emitted from the No. 1 to No. 3 reactors as of June. That is about one-80 millionths of the level that was being spewed immediately after the accident. Achieving a state of cold shutdown has meant a decrease in the volume of cesium emitted from the reactors.