Norway Reactor Incident Not Cause Of Europe Iodine Releases, Says France’s IRSN

12 Apr (NucNet): An incident at the Halden Boiling Water Reactor (HBWR) in southeast Norway at the end of October 2016 resulted in limited release of radioactivity into the environment, but was not responsible for atmospheric measurements of iodine detected in several European countries since January 2017, France’s Radioprotection and Nuclear Safety Institute (IRSN) said in an information note published on11 April 2017. IRSN said the Halden release, provisionally classified at Level 1 of the International Atomic Energy Agency’s International Nuclear and Radiological Event Scale (INES), concerned the period from October to November 2016 and could not therefore be the cause of radioactive iodine at trace levels detected in Europe in early 2017. The HBWR, a research reactor operated by the Institute for Energy Technology, was commissioned in 1959 and has a maximum thermal output of 25 MW. In the early afternoon of 24 October 2016, while the unit was shut down for maintenance, an incident during handling operations of a test assembly led to the release of radioactive substances. Small amounts of radioactive iodine were detected in the atmosphere in several European countries in January 2017. Radiation monitors in Finland, Norway, Poland, the Czech Republic, Germany, France and Spain all detected a small amount of an Iodine-131 isotope, nuclear regulators said. The largest concentrations were measured in Poland, but even those levels were “very far” from concentrations which could potentially have any effect on human health. IRSN said preliminary reports showed the iodine was first found in the second week of January 2017 in northern Norway. The origins of the iodine findings remain unknown. Iodine-131 isotopes are used for medical purposes and are manufactured in a number of countries. Iodine-131 is produced in nuclear power reactors as a fission product and is also used as a tracer in drilling industries.