Leakage of Coolant Water from Nuclear-Powered Submarine USS Houston
August 5, 2008
- In the afternoon of August 1, the Government of the U.S. gave the Ministry of Foreign Affairs the following information concerning a leakage of coolant water from the nuclear-powered submarine USS Houston.
(1) The U.S. Government provides the Government of Japan with this information from the viewpoint that on issues concerning the safety of nuclear-powered vessels, the Government of the U.S. shares all information with the Government of Japan and thus achieves accountability.
(2) A weeping of coolant water was confirmed during a regular inspection of the submarine now being conducted in Hawaii. It is unknown when the weeping started.
(3) The total amount of radioactivity released into the sea during the recent navigation was less than one half of a micro curie (or 0.0000005 Curie), or less than the quantity of naturally occurring radioactivity in one bag of common lawn and garden fertilizer. The amount of radioactivity involved is extremely small, and poses no risk to human health or the environment.
- The Government of Japan requested the U.S. Government to confirm that
the total amount leaked would have no risk to human health or the environment.
The U.S. Government then reconfirmed this. The Government of
Japan also requested the U.S. Government to provide any new information
promptly.
- When a U.S. nuclear vessel calls at a Japanese port, the Ministry of
Education, Culture, Sports, Science and Technology monitors radioactivity
on a round-the-clock basis. During the monitoring that was done in
March and April when USS Houston called at Japanese ports, no unusual amount
of radioactivity was detected.
- This morning, the above information was notified to Nagasaki Prefecture, Sasebo City, Okinawa Prefecture, and other local governments.
Related Information (Japan-U.S. Security Arrangements)
Related Information (Japan-U.S. Relations)
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