Tokyo Electric Power Co. this week announced plans to cover unit 3 at its damaged Fukushima Daiichi nuclear plant while declining to nail down a restart schedule for reactors at Kashiwazaki-Kariwa.

Recent developments related to the accidents at Fukushima following last year's earthquake and tsunami include:

Unit 3 to Be Covered

On Wednesday, TEPCO announced plans for a structure to shield the roof of unit 3, which was destroyed in a hydrogen blast early in the crisis. Work will begin as soon as crews finish clearing debris from the unit's upper floors, the Asahi Shimbun reported. Unit 1 has already been covered, and work is underway for a similar cover at Unit 4. The design for the 54-meter-tall unit 3 cover will include a steel frame, filtered ventilation and an arched section at its top to accommodate a crane to remove the reactor's fuel.
 
Kashiwazaki-Kariwa nuclear plant improvements. Source: TEPCOWorld's Largest Nuclear Plant to Remain Offline

TEPCO's Kashiwazaki-Kariwa nuclear plant – the largest in the world by total generation capacity – won't be restarting any time soon. Both the utility and the Japanese government that is its majority owner had hoped the restart of Kashiwazaki-Kariwa reactors would cut back TEPCO's mounting fossil fuel costs and help stabilize its finances. But in an interview with Reuters this week, a plant manager said it is too early to discuss when Kashiwazaki-Kariwa will resume electricity production. New walls to protect the plant from tsunamis will not be finished until June, he said, around the time Japan's new nuclear oversight body plans to release revamped regulations for the industry. New walls have been finished around three of the plant's seven reactors so far.

Photo: Kashiwazaki-Kariwa nuclear plant safety upgrades. Source: TEPCO