TOKYO (AP) -- A former U.S. nuclear regulatory chief said Tuesday that leaks of contaminated water at the crippled Fukushima plant had been known since early in the crisis and have worsened because Japan acted too slowly.
Gregory Jaczko said that U.S. and Japanese officials knew leaks would occur when massive amounts of water were used to cool molten reactors at the Fukushima Dai-ichi plant after a major tsunami hit in March 2011.
Jaczko said he was surprised how long it took Japan to start tackling the problem.
"It's been known for a long time that this would be an issue," he told a news conference in Tokyo. "My biggest surprise is to some extent how it's been allowed to deteriorate, a little bit, and how it's almost become a surprise again that there are contamination problems, that there is leakage out into the sea."
When the plant was in critical condition with three reactor cores melted and in dire need of cooling water, Jaczko said Japanese and U.S. officials disputed how much water should be put in because of the imminent leaks of radiation contaminated water and measures needed to contain that problem.
He said the Japanese government was concerned that the flooding those reactor vessels and reactor buildings with cooling water "would lead to greater leakage of ground water," whereas the NRC emphasized the need to keep reactors cool and under control to minimize the airborne contamination.
But the "focus was lost" on the need to keep addressing the radioactive water problem, apparently delaying action on mitigating the problem, he said.
Japanese officials confirmed for first time in July that contaminated ground water has been leaking into the Pacific from soon after the accident.
Leaders of the opposition Democratic Party of Japan, which was in power during the crisis, acknowledged last week that a plan to build a seawall to block contaminated water leaks into the sea has been put off for nearly two years after plant operator Tokyo Electric Power Co. allegedly resisted the plan for financial reasons.
The public has grown worried about the recent string of underground water leaks into the ocean and from storage tanks holding contaminated water used to cool the reactors.
The government is funding the development of more advanced water treatment equipment and paying for a costly ice wall to surround the reactor and turbine buildings and prevent them from contaminating outside groundwater.
Jaczko, who resigned as chairman of the U.S. Nuclear Regulatory Commission last year, was in Tokyo at the invitation of a Japanese anti-nuclear citizen's group.
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