INVESTIGADORES
VELASCO Ricardo Hugo
artículos
Título:
Temporal attenuation of gamma dose rate in air due to radiocesium downward mobility in soil
Autor/es:
VELASCO, HUGO
Revista:
HEALTH PHYSICS
Editorial:
LIPPINCOTT WILLIAMS & WILKINS
Referencias:
Lugar: Philadelphia; Año: 2020
ISSN:
0017-9078
Resumen:
Chernobyl and Fukushima Dai-ichi Nuclear Power Plant accidents have evidenced thatradiocesium deposited on the ground was one of most important pathway contributionto the air dose rate. 134 Cs contributes more significantly in the first period of 2-3years. Instead 137 Cs external exposure may remain relevant for decades. Thecontribution to the air dose rate attributable to these radionuclides is maximum at thedeposition time and then usually decreases over time. The dose rate temporalreduction is consequence of both the radionuclide physic decay and the radionuclide downward mobility in soil. In this investigation this decreasing behavior of the air dose rate is approached using an empirical attenuation function and its coefficients are computed in terms of the effective diffusion coefficient and downward migration rates of radiocesium in soil. The methodology is tested for different hypothetical scenarios and in real situations including areas affected by the two major accidents at nuclear powerplants.