Problem
Your quality control/quality assurance manager has requested your assistance in the testing and repair facility. One of the test procedures utilizes a radiation source that is emitting gamma radiation at a rate of 50 mrem/hour at a distance of 1 foot. This testing is done for approximately 2 hours per day, 2 days per week. The Occupational Safety and Health Administration (OSHA) has a PEL of 1.25 rem per quarter and 5 rem per year.
1) Determine the employee's exposure for 1 year.
2) Calculate the exposure rate if the employee was moved to a distance of 3 feet from the radiation source.
3) Calculate the exposure rate of the employee if a 5 cm lead shield was installed between the source and the detector. The employee is working at a distance of 1 foot from the source. [µ for lead, (662 keV gamma ray) = 1.23cm-1]