According to Tepco, Cesium-134/137 density reached the highest reading in 3 locations of Fukushima plant port.
The samples were taken on 8/28/2015. Those sampling locations are the center of Fukushima plant port, water intake of Reactor 1 and 2, where are outside of underground wall.
In the center of Fukushima plant port, Cs-134/137 density (79,000 Bq/m3 in Cs-134/137) became as double as the previous highest reading measured at this point this July.
Additionally, Cs-137 was detected for the first time in the North of the plant, where is outside of the port. The density was 800 Bq/m3.
Source: Fukushima Daiichi