A radioactive leak has been reported at a nuclear research reactor in southern Norway, authorities have said.
The leak was detected at the Institute for Energy Technology (IFE) in Halden.
The reactor sustained a leak of radioactive iodine, the Norwegian Radiation Protection Authority (NRPA) said.
In a statement, the NRPA said the discharge occurred "due to a technical failure during treatment of the fuel in the reactor hall".
The incident is not expected to harm the environment outside the reactor, it added.
According to the NRPA, the incident happened yesterday afternoon.
The authority says it is looking into why it was not informed until earlier today.
Radioactive iodine, also known as I-131, is used in small doses to treat thyroid cancer.
It has also been used to treat over-active thyroid disorders.