In Finland, Radiation and Nuclear Safety Authority (STUK) is the competent authority and
the national warning point with respect to bilateral and international agreements. STUK
has drafted proposals for new guides for intervention levels in different phases of an
emergency to be adopted by the Ministry of Interior (MoI) in Finland. These guides are
written separately for early phase and intermediate phase of a radiological emergency.
STUK selected 20 mSv effective residual dose from all exposure pathways during the first
year of an emergency as the reference level. This overall goal has been supplemented with
the following general guidance; if a projected dose without protective measures is during
the first year: (1) higher than 10 mSv, it is necessary to perform protective measures;
radiation expose is dominant in decision making, (2) 1–10 mSv, protective measures are
usually justified but other factors effect decision making, (3) below 1 mSv, the
protective measures may be carried out especially if they are easily feasible; other
factors are dominant in decision making. More specific criteria are given for separate
countermeasures as a projected dose in a certain time period or as an operational
intervention level (OIL) in a quantity which can be directly measured (external dose rate,
magnitude of surface contamination, concentration level) or as a trigger (such as plant
conditions). This paper presents the main intervention levels and criteria to be used in a
radiological emergency for members of the public.