668 Chapter 11. Dosimetry and Radiation Protection
14.A radiation worker works for 4 hours a day for 5 days in the radiation envi-
ronment depicted in the previous exercise. If, on the average, he remained at
adistanceof2mfrom the source during the whole time, determine the total
dose he would have received. Should this worker be allowed to keep working
in radiation environments?15.Estimate the thickness of lead required to decrease the exposure rate from a
cobalt-60 source by 99%. Assume the attenuation coefficient to be 0.6cm−^1.