Officials of Tokyo Electric Power Co. are racing to install purification equipment for the tons of water contaminated with radiation that have accumulated at the crippled Fukushima No. 1 nuclear power plant over concerns that it will leak out either into groundwater or the ocean.
Officials of Tokyo Electric Power Co. are racing to install purification equipment for the tons of water contaminated with radiation that have accumulated at the crippled Fukushima No. 1 nuclear power plant over concerns that it will leak out either into groundwater or the ocean.
TEPCO officials want to complete the installation by June 15 and begin purification of the water, which will be stored in tanks and recycled to cool the reactors.
As of the end of May, there was a total of 105,100 tons of contaminated water that had accumulated at the Fukushima No. 1 plant reactors.
Left as is, it would have only been a matter of time before the water leaked outside the plant.
TEPCO officials put together a plan to pump out the contaminated water from the turbine and other buildings in the plant, lower the level of radiation of the water through the purification process and reuse that water to cool the reactors. The purification equipment plays a key role in TEPCO's work schedule to achieve a circulating water cooling system.
"Once the equipment begins operating, the amount of water pumped into the reactors and the amount of contaminated water will be reduced," said TEPCO official Junichi Matsumoto.
The contaminated water will be purified through a five-step process.
Because the contaminated water also contains oil from the equipment at the plant, the first step will be to separate the oil from the contaminated water.
The next step involves using zeolite to absorb the radioactive cesium in the water, and a special solution will be mixed in for the third step to allow cesium and strontium to precipitate.
At the conclusion of that third step, the levels of radiation in the supernatant water will theoretically be reduced to one-thousandth to one ten-thousandths of the original level.
Because the supernatant water also contains seawater, there will be a need to desalinate it by using a reverse osmosis membrane to prevent the salt from damaging metal parts in the plant.
The desalinated water will be vaporized in the final step to reduce its volume.
The contaminated water in the No. 1 to No. 4 reactors will be purified using this equipment. The purified water will then be stored in tanks to prevent the contaminated water from overflowing within the plant grounds.
TEPCO workers are also rushing to complete the installation of pumps to the reactors. Fresh water is now being pumped in from a dam in Okuma, Fukushima Prefecture, but once the pumps are connected, the stored water will be reused to cool the reactors in the plant.
The purification equipment is being installed near the underground central waste processing facility where about 13,000 tons of contaminated water has been collected.
Once the equipment has been installed, plans call for it to purify a total of 250,000 tons of water by the end of the year.
While there were some initial reports that purifying the contaminated water would cost 20 trillion yen ($249.24 billion), TEPCO officials estimate that the system now being installed will cost a total of 53.1 billion yen to construct and process the 250,000 tons of water. That translates into a cost of 210 yen to purify a liter of contaminated water.