TEPCO says stabilizing troubled reactors to take at least 6 months
Tokyo Electric Power Co. said Sunday it will take at least six months before the utility can stabilize troubled nuclear reactors at the Fukushima Daiichi power plant, saying that about three months are needed to achieve a ''steady reduction'' in radiation leaks.While announcing for the first time its schedule for bringing the situation under control since the earthquake and tsunami crippled the plant's critical cooling systems on March 11, the utility, known as TEPCO, continued its containment efforts by operating remotely controlled robots inside one of the damaged reactors.
At a news conference in Tokyo, TEPCO Chairman Tsunehisa Katsumata said he is considering resigning from his post at an ''appropriate time'' to take the blame for one of the world's worst nuclear crises, indicating that the company's president, Masataka Shimizu, will also step down.
Under the schedule, the utility aims to bring the damaged Nos. 1 to 3 reactors at the plant in Fukushima Prefecture to a stable condition known as a ''cold shutdown'' in about six to nine months, a situation in which water temperatures inside the reactors have been stably brought below 100 C.
Noting the urgent task of preventing radioactive materials from spewing out of the seaside plant, Katsumata said, ''We will do our utmost to curb the release of radioactive materials by achieving a stable cooling state at the reactors and spent fuel pools.''
The utility said it will work on restoring stable cooling to the reactors and spent fuel pools in about three months, while seeking to control radioactive emissions and curb radiation substantially in an additional three to six months.
TEPCO added it is addressing the immediate challenges of preventing hydrogen explosions at the Nos. 1 to 3 reactors and preventing water contaminated with high-level radiation from the No. 2 reactor from leaking outside the complex.
Prime Minister Naoto Kan, who recently instructed TEPCO to show its schedule for resolving the crisis, told reporters later in the day, ''I feel that we have made a little progress.''
Industry minister Banri Kaieda said the government will review evacuation areas around the plant after the operator brings under control the release of radioactive materials from the plant, which is expected to take six to nine months.
TEPCO also said it will put special covers on the heavily damaged outer buildings of the Nos. 1, 3 and 4 reactors as an emergency measure to prevent radioactive materials from spewing out of the buildings and contaminating the air and soil, with plans to complete the work in roughly six to nine months.
Over the medium term, however, the utility plans to cover the reactor buildings with concrete walls and roofs, it said.
The company said it will pour water into the structures containing reactor pressure vessels for the Nos. 1 and 3 reactors within roughly three months, while putting back into the pressure vessels any water that leaks out in the process.
For the No. 2 reactor, whose containment vessel is feared to have been damaged, the utility plans to seal with sticky cement a part in the vessel that is believed to have been breached. It hopes to begin cooling the reactor within roughly three months in the same manner as the No. 1 and 3 reactors.
At the plant on Sunday, electric power to the cooling system for a pool storing spent fuel taken out of the six reactors was suspended, TEPCO said. The problem is likely to be fixed soon and the suspension would have no major impact on the safety of the pool, it said.
The two robots used at the No. 3 reactor are designed to read temperatures, radiation levels and the levels of oxygen concentration inside the building, a maneuver made necessary due to the fear that workers entering the space would be exposed to high levels of radiation.
Data collected through the maneuver will be used to gauge whether it is safe for workers to enter the building and determine what work will be required to bring the crippled reactor under control.
The utility will consider examining the Nos. 1 and 2 reactors in the same manner, using two U.S.-made robots equipped with moveable arms.
The complex has been crippled by the devastating magnitude 9.0 quake and subsequent tsunami, with the resulting damage causing the spread of radioactive materials and forcing tens of thousands of residents around the plant to be evacuated.
On April 12, the government's Nuclear and Industry Safety Agency raised the severity level of the crisis from level 5 to the maximum level 7 on an international scale, recognizing that it matches the world's worst nuclear catastrophe in 1986 at Chernobyl.
==Kyodo
