World's largest transparent spherical ... Staff members seal the bottom of a water tank with Tyvek material ... The detector is equipped with 20,000 photomultiplier tubes of 20 inches ...

The Fukushima Daiichi Nuclear Power Station, where the release of treated water into the sea has begun, is pictured on Aug. 24, 2023. (Mainichi/Kentaro Ikushima) WASHINGTON (Mainichi) -- U.S ...