Utilities are swiftly moving to beef up their defenses against tsunami in light of the accident at the Fukushima No. 1 nuclear power plant.
Utilities are swiftly moving to beef up their defenses against tsunami in light of the accident at the Fukushima No. 1 nuclear power plant.
Moves were already under way before the industry minister instructed electricity companies Wednesday to develop emergency safety measures to protect reactors from tsunami.
The Nuclear and Industrial Safety Agency (NISA), the nation's nuclear industry regulator, is expected to evaluate progress of plant operators' anti-tsunami work within a month.
The Ministry of Economy, Trade and Industry called for three steps: deployment of firefighting vehicles and mobile power sources to cool reactors and storage pools holding spent fuel rods; establishment of procedures to respond to an emergency; and implementation of emergency drills based on such procedures.
All 54 commercial reactors and the prototype fast-breeder reactor Monju--except for 10 reactors at the Fukushima No. 1 and No. 2 nuclear power plants--are subject to the instruction.
Fourteen of the plants have been shut down for scheduled maintenance. NISA will likely have to sign off on the operators' emergency steps before the plants can resume operations.
According to a survey of nine nuclear reactor operators by The Asahi Shimbun, all have either deployed new power-source vehicles or made arrangements for their deployment.
The crisis at the Fukushima No. 1 plant was put in motion when the emergency electricity source to cool cores and spent fuel storage pools was disabled by the tsunami.
Kansai Electric Power Co., which operates nuclear plants in Fukui Prefecture, said it has arranged for 22 power-source vehicles.
It will add 21 portable diesel generators and 70 pumps, the utility said.
Tokyo Electric Power Co., operator of the embattled Fukushima No. 1 plant, reported it has begun to make buildings housing nuclear reactors and buildings that pump seawater to cool generators water resistant at its Kashiwazaki-Kariwa plant in Niigata Prefecture.
Chubu Electric Power Co. said power-source vehicles and generators are now available at the Hamaoka nuclear power plant in Omaezaki, Shizuoka Prefecture.
The company is also considering construction of barrier walls more than 12 meters high.
The utilities' defenses against temblors are drawn up based on central government anti-quake guidelines.
But measures against tsunami were for the first time incorporated into the 2006 guidelines, the first revision in 28 years.
Safety precautions for the 54 commercial reactors in service and Monju were in line with the old guidelines.
NISA is evaluating the utilities' proposed safety rules based on the revised guidelines, but screenings of only five reactors and Monju have been completed.
At the Fukushima No. 1 plant, 12 of 13 emergency diesel generators were knocked out by the 14-meter-high plus tsunami.
TEPCO was prepared for a tidal surge of only 5.7 meters.
Hokkaido Electric Power Co. was theoretically best prepared, factoring in a possible tsunami of 9.8 meters high.
NISA officials acknowledged Wednesday they had not expected a 15-meter tsunami.
Earlier, TEPCO submitted to NISA an interim report on revised safety measures for the Fukushima No. 1 plant.
Although the utility was instructed to take into account a massive tsunami, which had hit the northeastern region at intervals of 450 years to 800 years, at a gathering of experts in 2009, it failed to finalize the report.
While utilities are actively crafting anti-tsunami steps, their focus is limited to deployment of mobile power sources and adding watertight features to buildings. They are not at present looking at radical redesigns or measures.
As a result, local governments hosting nuclear plants appear far from reassured by the ministry's instruction.
"Those safety precautions came too late," said a Niigata prefectural official dealing with nuclear power stations.
The official also raised doubts about the ministry's call for the deployment of power-source vehicles, calling it a stopgap measure.
Chubu Electric has been unable to restart the No. 3 reactor at its Hamaoka nuclear plant, which has been idle for checks since November.
The operator secured emergency power vehicles before the central government issued the instruction.
It also plans to build a breakwater more than 12 meters high and locate emergency generators upland from the plant. The company also held emergency drills Tuesday to prepare for resuming nuclear power generation.
But Shizuoka Governor Heita Kawakatsu suggested Wednesday it is difficult to accept the plant's reopening. "We have not been given details of damage (at the Fukushima No. 1 plant) and the central government's policy," he said. "No matter how much they stress safety of nuclear plants, they cannot eliminate public concern."