, , , , , , ,

Pressure inside the Fukushima Daiichi nuclear power plant‘s No. 2 reactor fell early Tuesday after relief valves were opened, but the fuel rods remain exposed, Tokyo Electric Power Co. said, according to Nikkei.com.

The pressure was relieved about 1:10 a.m. Tuesday local time (12:10 p.m. Monday ET), about two hours after safety valves closed inexplicably, fully exposing the fuel rods, Kyodo Newsreports.

The utility said the latest pressure reading suggests that there is some seawater left to cool the reactor.

The No. 2 reactor shut down at 2:48 p.m. Friday, two minutes after the magnitude 9 quake struck off the northeast coast of Japan. The reactor’s control rods are fully inserted, and the utility does not believe that reactor coolant has leaked into the containment vessel. But temperatures and pressure rose Saturday, forcing the plant operator to vent radioactive steam.

Earlier, a Japanese nuclear official said it appears the fuel rods in three of the plant’s six reactors appear to be melting.