On 9/26/2013, Tepco announced reactor5 and 6 pump up 6,000 tones of seawater from the plant port per hour. The water is used to cool down the reactors, and it’s discharged to the outside of the plant port.
In the presentation to IOC, Japanese prime minister Abe stated the contaminated water is completely blocked in Fukushima nuclear plant port, but it turned out to be false.
(cf, JP PM Abe to IOC “Contaminated water is completely blocked”→Tepco “Tritium can’t be blocked” [URL])
From Tepco’s own report published this August, it was 7,000 m3/hour instead of 6,000 tones/hour.