Fukushima Daiichi Floods, Show Lack of Preparedness
News reports indicated that groundwater at Fukushima Daiichi had risen so high it broke the surface and flowed into the port as a recent typhoon passed through the area. As TEPCO prepared to close the steel sea wall and freeze the underground frozen wall, NRA stopped the process for a review of the potential for flooding within the reactor building area.
The conclusion was that TEPCO thought they could sufficiently remove excess groundwater with the sump pump subdrain system near the reactor buildings. There were also concerns of the groundwater dropping too low, allowing contaminated water to flow out of the reactor building basements.
With all this review, nobody conceived a need for more water removal capacity. TEPCO ended up employing some sort of makeshift pumps and also using septic tank trucks to pump up water. This lack of anywhere for rainwater to go may have contributed to the water flowing out into the port as it built up on the surface.
Without some major changes at Daiichi this problem of groundwater rising to the surface and flowing into the port or the sea will continue to happen when significant rainfall takes place.
Typhoon rain raises tainted Fukushima plant groundwater to surface
Heavy rain brought by Typhoon Malakas caused contaminated groundwater to rise to ground level at the radiation-hit Fukushima No. 1 nuclear plant Tuesday night, raising fears of tainted water flooding out to the plant’s port area, its operator said.
Tokyo Electric Power Company Holdings Inc. said in a press release that plant workers are doing their utmost to pump up tainted groundwater at the Fukushima compound, while trying to measure the level of radioactive substances contained in the water.
Under normal circumstances, groundwater taken from wells around the damaged reactor buildings at the Fukushima plant is filtered and stored in numerous tanks built on the compound.
Shortly before 10 p.m. Tuesday, groundwater reached the surface level at an observation well near the seawall at the power plant’s port, and at 11:30 p.m. Tuesday, groundwater stood at 3 cm above the surface level, Tepco said.
The well has a far higher wall and the ground around it is paved, the company said, playing down the possibility that any water flowed out of the well.
By 9 a.m. Wednesday, the water level had dropped to 3 cm below the surface.
Meanwhile, some rainwater may have flowed directly into the port before seeping underground, according to the company.
Tepco will continue pumping groundwater around the seawall, located near the damaged No. 1 to No. 4 reactors, and carry out close examinations of water inside the port, the company said.
In order to curb the flow of groundwater into the sea, the company has covered the seawall with water shields and carries out groundwater pumping operations.
Typhoon Malakas itself was downgraded to an extratropical depression at around 9 p.m. Tuesday as it moved along the coast of the Tokai region and swayed toward the Pacific. It was initially forecast to hit the Kanto region in the early hours of Wednesday.
The previous typhoon, Lionrock, earlier this month killed at least 17 people. Before Lionrock, two typhoons had claimed at least two lives in the northeast.
TEPCO: Possible water leak at Fukushima plant during typhoon
Tokyo Electric Power Co. said Sept. 21 it will check for radiation contamination in seawater near its crippled Fukushima nuclear plant after heavy rain from Typhoon No. 16 brought tainted groundwater to the surface.
The water reached the top of wells at the Fukushima No. 1 nuclear power plant, and there is a possibility that some of it spilled into the sea.
“We will analyze the seawater because we cannot determine whether groundwater containing radioactive materials has actually leaked,” a TEPCO official said.
The official added that the company believes most of the water that may have poured into the sea was rainwater that had not seeped into the ground.
The utility constantly monitors groundwater levels in wells around the reactor buildings at the plant to prevent overflows.
TEPCO said groundwater in wells on the seaside area of the nuclear complex reached the surface around 10 p.m. on Sept. 20 amid the heavy rain brought by the approaching typhoon. The water kept rising despite workers’ efforts to lower the level using makeshift pumps and septic tank trucks.
The groundwater level remained the same as of 7 a.m. on Sept. 21 before it finally dropped to about 3 centimeters from the surface two hours later, the company said.
According to TEPCO, about 575 millimeters of rain fell in the area of the nuclear plant from Aug. 1 to Sept. 20.