Kw. Nicholson et Mj. Fulker, THE ATMOSPHERE SURFACE EXCHANGE OF RADIONUCLIDES AT THE SELLAFIELD REPROCESSING PLANT, Journal of aerosol science, 25(5), 1994, pp. 807-820
A programme of field measurements has been undertaken in which the dep
osition rates of Pu and Cs have been measured around a nuclear reproce
ssing facility. Dry deposition velocities have been found to be typica
lly in excess of 1 cm s-1 and were highest for Pu. On occasions, bulk
deposition velocities for Pu averaged over a period of several weeks o
r longer were considerably in excess of 10 cm s-1. Such values can onl
y be ascribed to the local resuspension and subsequent deposition of v
ery large particles which have high deposition rates and which would n
ot be efficiently collected by the air samplers used to determine the
deposition velocities. Size fractionation measurements of radionuclide
s confirm a substantial presence of large particles. The overall study
shows that the neat-surface deposition flux is dominated by previous
deposition rather than current atmospheric discharges.