Safety_Series_041_1975 - gnssn - International Atomic Energy ...

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82 APPENDIX IV
blowing from NNW and valley breeze from SSW; fohn blows from the
Northern directions and the Atlantic perturbations come from NNW.
The wind rose recorded at the Observatory of the Establishment
shows a dual symmetrical distribution. Figure 10 reports the
percent frequency of the six categories of atmospheric stability
according to Pasquill, associated with the corresponding wind
directions. It will be remarked that category D prevails in the
northern directions, whereas the unstable categories are generally
associated with valley breeze from SW.
On the basis of the radionuclides present in the effluents and
of the characteristics of the environment, the principal critical
pathways of exposure have been identified as given in Table XV.