Planned reference and intervention levels in Finland

STUK, Radiation and Nuclear Safety Authority, P.O. Box 14, 00881 Helsinki, Finland.

Abstract

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.