A person is immersed in a radiation field produced by a source of 10 Ci of Cs-137. The fountain is located 1.5 m from the workplace of the person in question and is contained in a Pb shield whose thickness is 5,715 cm (2.25 in.).

A) What is the maximum time that the person can stay in their workplace so as not to exceed the dose limit suggested by the international recommendations for POE?

Hints: - Interpolate linearly in the graph of B vs x to find the value of B that

Corresponds to the energy of the Cs-137 for the given Pb thickness. You can rely on the lines already drawn.

- Consider that a year has 254 working days and calculate the daily dose limit. Use that value as the dose limit.

- Consider whole-body exposure and remember that for whole-body exposure the effective dose and the equivalent dose have the same numerical value. - Assume that the human body can be modeled in its entirety as water. Failing that, use the following approximation: 1mR 10Sv. b) Considering an 8-hour workday, what should be the distance between the radiation source and the person's workplace?