FAQs for Radiation Safety

You can find most answers to questions regarding radiation safety in the University of Kentucky Radiation Safety Manual. A copy of the manual should be available in laboratories belonging to Authorized Users of radioactive material. If you do not have a copy in your laboratory and should have, contact the Radiation Safety Office at 3-6777.

  1. How do you fill out a waste ticket to notify Radiation Safety to pick up radioactive waste?
      All radioactive waste to be picked up by Radiation Safety must have a waste ticket. To learn how to complete the ticket to the website Radioactive Waste Pickups.

  2. How do you complete the monthly radioactive material inventory form?
      Monthly inventories are required from all Authorized Users. Go here to learn how to complete the form.

  3. What type of shielding and how much do I need for a particular radioisotope?
      A table providing shielding information can be found here.

  4. Why do only certain individuals need to wear dosimetry?
      Dosimetry is issued to an individual based on the likelihood that individual will receive greater than 10% of the occupational exposure limit. The policy for wearing dosimetry may be found in Chapter 9 of the Radiation Safety Manual or at the website titled Obtaining a Film Badge.

  5. What are the requirements for separating waste?
      Primarily waste must be separated according to waste type (i.e. liquid, solid, liquid scintalation vials, animal carcass). In add it is important to separate waste according whether it contains long-lived or short lived material. The requirements for separating waste may be found in Appendix G of the Radiation Safety Manual or the website titled Radioactive Waste Pickups.

  6. How do I perform a wipe test?
      Go here to learn how to perform a wipe test.

  7. Why do I need to perform wipe tests when I have not used radioisotopes for so long?
      All active Authorization require, at a minimum, monthly wipe tests. If you are not actively using radioactive material in your laboratory you should consider going on inactive status or closing out your authorization. If you go on inactive status, you only need to perform wipe tests on a quarterly basis. While if you close out your laboratory you do not need to perform wipe tests at all.

  8. How do I complete the scintillation drum sheet for a multi-user laboratory?
      The authorized user responsible for the room should have their name at the top of the sheet designated the Authorized User. Multiple users list their name on the form next to the radioisotope and activity that they are adding to the drum. These individuals may be other Authorized Users or their staff.

  9. Why do we only track radioisotope in the original vial?
      The purpose of the tracking is to document the disposition of the activity of the order. The vial has been assigned a shipcode by the Radiation Safety Office. If you were to aliquot several substocks from one shipcode for use at a later date, the activity on hand in the aliquots would remain in your inventory. Using the subtraction system of inventorying with our database, the activity in the aliquots remains in the Authorized User's account until it has been assigned to a waste stream via the radioactive materials monthly inventory form.

      When the total activity of the vial has been disposed, the shipcode will be deleted from your account.

      If a significant activity of the materials will remain in samples in the laboratory, the shipcode may be active for some time.

  10. How do I know if I had an over exposure?
      If you receive an exposure in excess of the ALARA Notification Levels you will be notified in writing. See Chapter 9 of the Radiation Safety Manual for the notifcation levels. If you exceed the occupational limits for exposure you and your supervisor will be notified immediately by the Radiation Safety Officer.

  11. Why do our meters work so much better than their meters?
      The annual calibration done on all meters at UK ensures that the dose rate reading from a specific source is within +/- 10% of the standard. Contamination detection is not that simple.

      The reading from a GM meter is proportional to the number of ionizing events counted in the gas filled chamber of the instrument and is also affected by the voltage setting of the meter. The pancake detectors we use are more expensive, but they also have a larger window than an end window. Therefore more counts from a given source are detected by the larger face. Newer instruments would be closer to the ideal voltage set at the factory, which could change with age, and lower the efficiency. All of our instruments are relatively new.

      Therefore, the size of the detector, the thickness of the window, and the operating voltage all can effect how well a meter performs.

Radiation Safety