Radioactive leak reported in Norway

A small amount of radioactive iodine leaked from a nuclear reactor in Norway before it was contained, authorities said Tuesday.

The leak at a reactor at the Institute for Energy Technology about 70 miles from Norway's capital Oslo was caused by a technical problem that occurred when its fuel was being treated, Norway's Radiation Protection Authority (NRPA) said in a statement.

The leak started Monday at 1:45 p.m. local time (7:45 a.m. ET) but was only revealed Tuesday. Authorities were trying to account for the delayed announcement.

Chernobyl disaster: 30 years later

NRPA said the leak, now contained, was not expected to harm the health of the facility's workers or the environment. The reactor — called Halden — was built in 1958. It is used for nuclear safety-related research, mainly on materials and fuel.

In small doses, radioactive iodine, also known as I-131, can be used to treat thyroid cancer. But exposure to large quantities of I-131 can increase the risk for developing leukemia.

On April 26, 1986, an explosion destroyed a nuclear reactor at Chernobyl's Vladimir Ilyich Lenin Nuclear Power Station in the former Soviet Union, now modern-day Ukraine. That incident is widely considered to be the world's worst nuclear catastrophe. Five million people still live on heavily contaminated lands there and hundreds of thousands of people are sick or suffering.