Work to restore key equipment at the Fukushima No. 1 nuclear plant's crippled reactors continued Thursday, despite reports of smoke rising from reactors No. 1 through 4.

The lights were turned back on in the central control room of reactor 1 at 11:30 a.m., following Tuesday's news that the lighting was back in the reactor 3 control room.

Workers were preparing to test-run possibly by late Thursday a cooling pump to inject fresh water into reactor 3, instead of seawater that could damage components.