Partially used irradiated fuel from the Finnish Reactor 1 (FiR1) in Espoo, Finland, has been transported to the USA for use in a similar TRIGA Mark II research reactor operated by the US Geological Survey in Denver, Colorado. Dismantling of the Finnish reactor, which was shut down in 2015, is scheduled to begin at the end of 2022.

The fuel, purchased by Finland in the 1960s and 1970s, still has "a remarkable remaining utility value", VTT Technical Research Centre of Finland said. The USGS required additional fuel to continue operating its reactor, but the production of suitable fuel has been suspended for several years.

The contract for the supply of Finnish used fuel was concluded last November. VTT has now delivered the fuel to the USGS. The transport of fuel by road and sea was conceived and implemented by Washington, DC-based Edlow International, and was supervised by the Finnish Radiation and Nuclear Safety Authority (STUK) and US authorities.

The use of the Finnish fuel in the US reactor will enable the USGS to continue operating it for several years. VTT noted that at the end of operation, the USA will take responsibility for the final disposal of the fuel.

Arranging used fuel management abroad is an exception permitted by the Finnish Nuclear Energy Act, VTT noted. Before sending the fuel, Finland received a report from the US authorities on their commitment to the management of the fuel. When the USGS ceases to use its reactor, it will deliver the used fuel to the Idaho National Laboratory. The US Department of Energy will take responsibility for the fuel through a procedure that meets VTT's previous plans.

"The removal of used fuel is an important milestone in the decommissioning of the research reactor," said VTT Senior Scientist Markus Airila. "Next, we will focus on the final planning of and preparation for dismantling. The project creates new expertise in Finland, for which there is also international demand."

The FiR1 water-cooled, pool-type TRIGA Mark II research reactor was commissioned by the Helsinki University of Technology in 1962. The reactor was originally built for research and education and was later also used for isotope production and radiotherapy. Operational responsibility for the reactor was transferred to VTT in 1971. Although licensed to operate until 2023, VTT decided in 2012 to stop the use of FiR1 for financial reasons. The reactor - with a thermal capacity of 250 kW - ran for the last time on 30 June 2015. In 2017, VTT submitted an application for permission from the Council of State to decommission the reactor.

VTT announced the dispatch of the used fuel in a letter to the Finnish Ministry of Economic Affairs and Employment today, and excluded used fuel from its decommissioning licence application.

In April 2020, Finnish utility Fortum was awarded a contract by VTT to decommission FiR1. The contract followed the signing in December 2018 of a letter of intent by Fortum and VTT to cooperate in the decommissioning of the reactor. It will be the first nuclear reactor to be decommissioned in Finland.