Two bottles containing 336 grams of natural uranium have been found at a Niigata Prefecture high school, where they sat in a storeroom for more than 60 years, the prefecture said Friday.
According to the prefectural government, the bottles were found Aug. 21 in the chemistry storage room at Kashiwazaki High School in central Niigata.
They were believed to be part of a batch of chemicals a university in Tokyo had sent to the high school to keep during World War II.
The prefectural government measured the radiation in the bottles and said it posed no dangers to people or the environment.
The high school checks its chemicals every year, but the uranium was believed to have been overlooked because the labels had faded.
The high school plans to apply for permission to keep the uranium -- in a locked container.
According to law on nuclear reactors, storage of natural uranium of 300 grams is considered nuclear-fuel material and requires government permission.
"We have no means to dispose of" the uranium, a prefectural official said.
"We have to keep it under close guard."
