Following up this article..23,300 Bq/Kg of cesium from 4km of filter plant
The contamination level of Mizumoto Park turned out to be the same level of “off-limits zone” in Chernobyl.
The contamination level of the park was 23,300 Bq/Kg.
According to Nuclear Safety Commission, it is converted to be 1.4 ~1.5 million Bq/m2.
In Chernobyl, if the area is more contaminated than 1.48 million Bq/m2, it was labelled as off-limits zone, which was the worst level of the pollution.
Because cesium doesn’t choose Mizumoto park intentionally, at least some parts are contaminated as the worst area of Chernobyl.