[en] The radiological monitoring of radioactive effluents from nuclear power plants with DWRs or PWRs during normal operation does not include in general analyses of the contribution of aerosol-borne radionuclides with a half-life period smaller than 8 days. In order to evaluate this contribution to radiation doses, the study investigates all airborne radionuclides emitted from nuclear power plants equipped with an LWR during normal operation. A conservative assessment of emission rates is based on diffusion-model calculations of radionuclide release from fuel elements, assuming non-delayed transport into the surroundings; the study covers rare gases, halogens, alkaline metals, and oxidizing fission products. It is shown that the short-lived aerosol-borne radionuclides mainly are decay products of rare gas isotopes with half-life periods shorter than 3 hrs. Only Rb-88, Rb-89, Rb-90, Cs-138 and Cs-139 account for radiation doses that are worth considering. Rb-88 is the prevailing radionuclide of this type in PWRs, and in BWRs it is Cs-138. The radiation doses of interest are determined by calculating transport factors for γ-submersion as a function of radionuclide half-life periods using a simple, new model, and by calculating the missing dose factors for the various exposure pathways. The radiation dose to the population induced by these aerosol-borne radionuclides is due only to γ- or β-submersion. Since the radioactivity thus released is lower than that of the rare gases, while the dose factors for calculating external radiation exposure are almost identical, the radiation dose contribution from these short-lived radionuclides is only a fraction of that of the rare gases, so that it is justifiable to include this type of exposure in the calculations for assessing radiation exposure emanating from rare gases. This all the more as a direct measurement of these aerosol-borne radionuclides that are completely decayed after 6 hours is very difficult. (orig./HP)