Daiichi Enters Shutdown Phase

摘要

Nine months after the Fukushima Daiichi nuclear power plant was devastated by the earthquake and tsunami in March, the Japanese government says the plant has entered a “cold shutdown” period and decommissioning process which is expected to take more than 30 years. A plant enters a cold shutdown phase when temperatures at the bottom of the reactor pressure vessels (RPV) and inside the primary containment vessels (PCV) remain below 100° Celsius, and radiation within the boundaries of the site are capped below 1 millisievert per year. Operator Tokyo Electric Power (Tepco) said the current release of radioactive materials from the PCVs is 0.1 millisievert/yr. The embattled utility began efforts in April to bring the 6-unit plant under control by the end of the year (IOD Apr.19’11).