Surveys for contamination are the primary method of protecting ourselves and members of the public from internal and external exposure. Remember that contamination carries many connotations, and "contamination" is simply the same radioactive material you are using, but in an unwanted place. There is considerable variability from one lab to another in the specific survey methods employed. Therefore, it is important that laboratory personnel periodically review their laboratory's specific policies regarding the frequency and type of survey. You should know how often to perform your surveys and when it is best to perform non-routine surveys.
Frequency of surveys must be in accordance with Section 3.2 of the Radiation Handbook. You must perform daily surveys whenever RAM material is actively being used. Any date gaps or changes in frequency should be documented and referenced back to your use logs. Additional surveys are recommended, for example, immediately following labeling procedures. An additional survey is required after cleaning an area or equipment that was contaminated to show and document that it was cleaned to background levels. Many of these requirements are outlined in your authorization documents for radioactive materials. You should always take the time to survey yourself immediately following use of radioactive isotopes.
Use your portable survey instrument to first survey the lab and then take your smear surveys (both are required). Only H-3 use does not require a survey using a portable survey instrument. The efficiency of how much you pickup from the surface onto your smear is greatly enhanced by slight wetting. For any results of twice background, clean the areas and resurvey. Any printouts for recounts or surveys after cleaning should be attached to your routine survey records for inspection. Please notify the RSO if there are areas that are elevated despite your effort at repeated cleaning. We can also help interpret your counter printout (fax a copy to 516-6309) or conduct a second independent survey of your laboratory at your request.
All packages must be surveyed on receipt and the empty package must be surveyed before release as trash. Our staff surveys the outside and inside of all incoming packages, including the pig and vial holding the material, and verifies all orders prior to delivery.
Be sure to COMPLETELY destroy all package markings and labels by either tearing them off or using a large black permanent marker. This includes all radioactive material labels, the UN2910 limited quantity label, and any DOT hazard classification diamond labels.
First, smear the outside of the pig and check the smear by holding within a centimeter of the probe face. Next, smear the vial and again check the smear by holding toward the face of the probe. You must check your smears of the pig and vial by counting in liquid scintillation for low energy emitters like tritium. Also, be sure to survey the plastic bag if your pig arrived in a sealed plastic bag. You must notify RSO if any results are significant above background.
It is important that you properly survey yourself to check for all instances of potential personal contamination, since having material on you would be the most likely cause for spread of contamination.
The following is a step by step personal contamination survey:
For higher energy emitters, an initial brief over pass can be useful in detecting the location of larger quantities. Otherwise, it is very important that you slowly move the detector face across your skin and clothing in close proximity within about a quarter of an inch (0.5 to 1.0 centimeters). Surveying within a quarter of an inch is important for detecting moderate energy beta like S-35 or C-14. You should also pause for several seconds at the most likely points of contact, fingers, wrists, sleeves, pockets, front line and lapel of lab coat, balls and heals of shoes. You may exit when you are convinced that you are free of personal contamination. Remember that you must notify EHS immediately of any incident involving contamination of personal clothing or skin. In the event of an incident, laboratory members may be called upon by EHS to help survey the area and each other.
