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STUK’s tasks in the research reactor licensing process

STUK’s tasks in the research reactor licensing process

The FiR 1 research reactor and its associated storage facilities have a total of just over 100 fuel rods, for which VTT is responsible for safe handling and final disposal.

The fuel rods used in the research reactor are smaller and less radioactive than fuel rods in reactors of nuclear power plants. The research reactor fuel rod has a length of 70 centimetres and a uranium content of 8 to 12 per cent. The rods used in Finnish nuclear power plants are 3–4 metres long and their uranium content is about 88 per cent.

Some of the reactor structures have also become radioactive during use. VTT is also responsible for these structures, as well as for the proper storage and final disposal of the radioactive waste arising from the dismantling work.

STUK’s task is to review VTT’s decommissioning and waste management plans and to monitor decommissioning and dismantling works on site. STUK also ensures that VTT has the expertise and re-sources needed in the project.

According to STUK Guideline (YVL Guide D.4), VTT has to submit the final decommissioning plan for the research reactor to STUK for approval within two years of the final shutdown of the reactor, i.e. by summer 2017. STUK verifies that the plan meets the decommissioning provisions provided by law, decrees, regulations and YVL Guides. During decommissioning, STUK ensures that the plan is kept up-to-date and that the radiation and nuclear safety requirements are met as the dismantling work progresses and ends.


When the dismantling of the reactor begins, STUK oversees that VTT takes appropriate steps to ensure the radiation and nuclear safety of employees, the environment and members of the public. The grounds for this responsibility are found in the international regulations, the Nuclear Energy Act, as well as in STUK’s own regulations and YVL Guides.

The decommissioning of the reactor is the first of its kind in Finland and also the first time STUK undertakes this particular responsibility. However, STUK’s experience and expertise in the supervision of active nuclear facilities provide a good basis for this undertaking. In the supervision of the dismantling of FiR 1, STUK can also take advantage of the experience gained from similar projects elsewhere in the world. The decommissioning of FiR 1 and the supervision of the project will provide valuable experience that can be utilized when the first nuclear power plants will eventually be decommissioned and dismantled in Finland.

Reactor core loading scheme.
A total of just over 100 fuel rods have been used in the Otaniemi research reactor. In total, the rods contain about 15 kg of uranium.

Finalization of decommissioning

Once VTT has completed the dismantling of the FiR 1 reactor and the radioactive waste is packed and delivered to the intermediate storage site until final disposal, STUK will check that all operations related to the dismantling and waste management have been safely carried out in the Otaniemi area.

VTT will submit to STUK an application for the release of the area and its buildings from regulatory control when the radioactive systems and structures have been dismantled, by 2020 according to the current plan. STUK will check that the buildings in the plant site are clean of radioactive materials in the way stipulated by the Nuclear Energy Act.  When purity has been verified and the area released from supervision, one can set up an office, cafeteria or anything in the place where the reactor used to be.

Resource plan

STUK plans to spend about 300 man-days during 2016–2020 for the regulatory control of the FiR 1 decommissioning. The most resource-intensive years will be 2017 and 2019–2020. In 2017, STUK will be reviewing the application for the operating licence and in 2019–2020 it will be supervising spent fuel maintenance and the dismantling of the actual reactor.

In 2018, VTT will carry out preparatory work mainly for the dismantling of the reactor, including detailed dismantling plans and preparation of the premises for the actual dismantling work and, in con-nection therewith, STUK will carry out its normal regulatory control duties. The costs of the work are borne by the holder of the operating licence, which is VTT.