Why is Japan dumping radioactive water into the ocean?

Radioactive water continued to drain from the damaged Fukushima Daiichi nuclear plant into the Pacific Ocean on Monday, as Japanese officials mounted a desperate effort to find and plug the source of the leak.

On Saturday, the Tokyo Electric Power Company (TEPCO) thought it had discovered the leak’s headwaters – a crack in a concrete pit near reactor No. 2. TEPCO workers poured concrete into the pit to close the breach, but the leak continued.

On Sunday, workers broke through the top of a connecting trench and dumped in a mix of sawdust, newsprint, and absorbent polymers in an attempt to glue the leak shut. That didn’t work either, noted the International Atomic Energy Agency in a Monday update on Fukushima’s status: “Leaking has not stopped.”

Radioactive water

As the Fukushima crisis passes the three-week mark, the thousands of tons of water – used to keep crippled reactors and spent-fuel pools cool – are becoming an increasing concern.

Much of the water evaporates, or else collects inside spent-fuel pools or other secure areas. But in the wake of the March 11 earthquake, water has also escaped from the damaged reactor buildings, flowing into the maintenance tunnels and basements, and then to unknown parts.

The problem now is that TEPCO does not have enough storage tank capacity at the site in which to store contaminated water. That is why the Japanese government Monday authorized Fukushima workers to release 10,000 tons of wastewater containing low-level radioactivity directly into the sea.

Dumping this water should free up space for TEPCO to pump highly contaminated water out of reactor No. 2’s basement and tunnels, potentially putting an end to the leakage problem.

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