Nuclear materials refers to nuclear materials, which include uranium, plutonium and thorium, as well as other nuclear materials, equipment, installations, data materials and agreements, if they are relevant in terms of the spread of nuclear weapons or are subject to the obligations of international agreements in the nuclear field. Like other uses of nuclear energy, activities related to nuclear materials are basically subject to a permit.
Monitoring of nuclear materials ensures that nuclear materials, nuclear facilities and technology in the field are used peacefully in accordance with permits and notifications. This is aimed at preventing the spread of nuclear weapons. STUK maintains and develops the national control system for nuclear materials, and its goal is to take care of fulfilling the obligations of the international nuclear non-proliferation treaty in Finland.
STUK regularly inspects the nuclear material safeguarding arrangements of nuclear material users, i.e. operators, such as accounting and reporting procedures as well as the organization's operations and guidelines. The operator and STUK must be aware of the location and use of all nuclear materials at all times. With the help of various verification methods, it is verified that the information about nuclear materials is correct and complete. STUK supervises, among other things, the importation, transfers and decommissioning of nuclear materials based on notifications from operators.
At least three times a year, STUK inspects the nuclear substances and materials at nuclear power plants, especially fresh and spent fuel. STUK conducts inspections for other significant users of nuclear material and materials annually, and for operators holding small amounts of nuclear material every two years or less frequently. In addition to its own inspections, STUK participates as an independent inspector and observer in all inspections by the International Atomic Energy Agency (IAEA) and the European Commission in Finland. A few times a year, the IAEA conducts a surprise inspection or a supplementary inspection visit to a place where nuclear material is used in Finland.
In addition to the actual nuclear materials, nuclear material control focuses on research activities related to the nuclear fuel cycle. In accordance with international agreements, STUK reports to the IAEA and the European Commission on the activities of the nuclear sector in Finland.