Quake cleanup delays reactor core checks

Tokyo Electric Power Co. may not be able to begin reactor core checks of its quake-hit nuclear power plant in Niigata Prefecture until September because it needs to clean up contamination inside one of the seven reactors and remedy other safety woes, company officials said Monday.

In addition to repairing the damage, the utility must also solve a host of problems that emerged after the magnitude-6.8 quake hit the Kashiwazaki-Kariwa nuclear plant July 16, including an inadequate fire-extinguishing system and uncertainty over the plant's ability to withstand earthquakes like the one that struck along the fault the complex apparently sits on.

Restarting the world's largest atomic power complex before the August peak power demand period is not expected.

A prolonged suspension may in turn cause other problems, including an increased release of carbon dioxide from thermal power plants Tepco will have to restart to make up for the shortfall.

To check the core contained in the reactor pressure vessel, Tepco said it must remove radioactive water believed to have leaked from a pool for storing spent fuel rods. Some of the water flowed into the nearby sea.

Since the quake, the water has been left on a floor located above the reactor pressure vessel at one of the seven reactors.

The vessel is filled with cooling water and an underwater camera is needed to inspect control rods and other materials inside.

The utility also has to check whether the crane set up to lift the vessel's lid is working properly.

"We need at least several weeks for these preparations, and the start of checkups will be after mid-August at the earliest and may possibly not be before September," a Tepco official said.

Tepco also needs to confirm how the water leaked into the sea, and repair buckled roads at the plant site as well as damaged fire equipment.

Even after all these problems are fixed, Tepco has to gauge the plant's ability to withstand a strong temblor and gain approval from the central government and local authorities before it can go back online.

"Since the earthquake, our hands are full in dealing with the issues that face us. We have not yet reached the point of deciding in detail about a future timetable," a company official said.