1. 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.
a. Determine the employee's exposure for 1 year.
b. Calculate the exposure rate if the employee was moved to a distance of 3 feet from the
radiation source.
c.
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. [u for lead, (662 keV gamma ray) = 1.23cm-¹]