Developments over the last week at the Japanese nuclear plant blacked out by the March earthquake and tsunami include:
TEPCO Anticipates Cold Shutdown By End of Year
Tokyo Electric Power Co. may declare that its three severely damaged reactors at the plant have reached cold shutdown status earlier than planned. A six month update to its “roadmap” to bring the plant under control released Monday indicated that could happen by the end of the year, instead of in January as anticipated. Temperatures within units 1 through 3 have already fallen below boiling. But TEPCO has said it wants to sustain the low temperatures and reduce radiation readings around the plant before confirming cold shutdown status, which is one of the criteria the government will use for lifting evacuation orders.
Temporary Cover Completed For Unit 1
In an effort to protect its damaged reactor building from the elements and help keep contaminated material from escaping, TEPCO recently completed a covering for unit 1. If tests through the end of the month show the steel and polyester structure is effective, the Nuclear Energy Institute reported, TEPCO may install similar covers at units 3 and 4.
Water Treatment System Making Progress, But Another Leak Reported
On Tuesday TEPCO reported 3 metric tons of irradiated water leaked from a rapidly assembled system designed to reduce widespread flooding at the plant.
The Asahi Shimbun quoted TEPCO as saying the water leaked from a cesium absorption unit and was confined to the treatment system site. Kurion makes the absorption units in the system designed by Areva and Veolia Water. After it was put online this spring, the treatment system made halting progress through a series of malfunctions and leaks, the biggest of which released 6 tons in June.
The system had treated about 130,000 tons of water, according to TEPCO’s report. The treated water is now being used to cool the reactors, and water levels in plant basements have declined significantly.