Tepco to curb toxic water leaks with tanks


Tokyo Electric Power Co. on Wednesday started pumping groundwater into tanks before it passes through the crippled Fukushima No. 1 nuclear plant and gets highly contaminated.

Pumped from wells, the water will first be stored in tanks, where its level of contamination will be checked. Once its safety is confirmed by analysis, which is expected to take about a month, Tepco will release the water into the Pacific Ocean.

The so-called groundwater bypass system is a key measure to slow the pace of increase of highly radioactive water accumulating at the plant. Local fishermen have OK’d the dumping of groundwater on condition that it passes stringent safety criteria.

About 400 tons of groundwater a day is seeping into the basements of reactor buildings and mixing with water used to cool three reactors that suffered meltdowns in the 2011 disaster, adding to the total volume of highly radioactive water at the plant.

Although Tepco is installing more tanks to avoid running out of storage space, it also wants to stop the total volume of radioactive water from further increasing. With the groundwater bypass system, Tepco says it can reduce the amount of water seeping into the reactor buildings by up to 100 tons per day.

  • Chandrakant Kulkarni

    Lot of confusion!..
    “About 400 Tons of groundwater——-Tepco says——by up to 100 Tons per day.”
    Means, about 300 Tons of water per day is not taken care of.
    Well, then what about water ‘stored in tanks’? As per my extremely limited knowledge, radioactivity is not like some chemical that has mixed into water. If water stored in tanks possesses radioactivity, it will continuously emit radiations to everything surrounding the storage tanks.
    Suppose, water belonging to some storage tanks indicates high / medium / low % contamination, how will it then be ‘purified’?
    The illustrative diagram shows ‘water tapping & pumping wells’ near to mountains- with an assumption that: like surface water streams, groundwater also follows ‘high altitude to low altitude’ flow pattern.
    Many times, the aquifer (=water bearing porous rock layer ) may be sloping in a reverse direction-as compared to surface topography.
    Moreover, pumping ‘uncontaminated’ water from wells ‘away from reactors’ may itself attract contaminated water in the proximity of reactors by virtue of the most natural ‘draw-down effect’. (This natural phenomenon is described under the topic: “Ground Water Hydraulics” in many text-books on hydro geology.)