M. Vladar et al., DERIVED INTERVENTION LEVELS IN THE EARLY-STAGE OF A NUCLEAR ACCIDENT, Journal of radioanalytical and nuclear chemistry, 209(2), 1996, pp. 285-290
A method of determination of derived intervention levels for temporary
evacuation of inhabitants in the case of nuclear accident of VVER NPP
type is described. 21 accidental sequences which may leads to the unc
ontrolled release of radioactive material to the environment have been
analysed. Effective doses for 48, 168 and 732 hours at distance of 5,
15 and 30 km from the source have been assessed on the base of result
s of calculating the kerma rate in air. It has been supposed that moni
toring will be performed 2 hours after finishing the accidental releas
e. The exceeding of 50 mSv intervention level up to 48, 168 and 732 ho
urs might be expected if kerma rate in air (DIL1) exceeds 0.4, 0.2 or
0.2 mGy.h(-1), respectively. Determination of effective doses at dista
nces under consideration also enables to assess the length of zone for
planning the temporary evacuation (DIL2). The zone length at meteorol
ogical situation of Pascquill stability categories D, height of releas
e 25 m and wind speed 2 m.s(-1) may exceed 30 km at the axis of the hy
pothetical track.