Number 39 April, 2001
The temporary radwaste container* such as the trash can, cardboard box, or plastic bag you use on or next to your benchtop must meet certain criteria. It must have a label or tape identifying the contents as radioactive, and it cannot be a red or orange biohazard bag. No one else may know what is in it; if you walk away from it, someone could move it or a custodian could empty it into the trash. If someone put an orange bag into the autoclave it could become contaminated. State regulations require that "each container of radioactive waste shall bear a label or tag identifying the contents at all times." Keep a roll of "caution, radioactive material" stickers or tape available for small jobs like this one. Write the nuclide and date on the label. If you can estimate the activity, put that on the label, too. Finally, if you intend to reuse the container for another purpose, it has to be surveyed and documented as clean before reuse. We recommend that you never put rad waste into an ordinary trash can. We recommend that you survey your laboratory trash cans periodically during periods of work with radioactive materials.
Daily operational checks of radiation survey instruments are important because they tell you whether your survey meter is functioning correctly before you use it. The best method is to use a small, long-lived check source counted in the same geometry each time. Other sources can be used such as a thorium lantern-mantle (now in short supply) or a FiestawareTM plate. When no other source is available you can aim the detector at a stock vial or waste container and see if you get a response. If you don't, make sure the instrument is turned on and the batteries are OK and try it again. If you still don't get a response, call us and arrange for getting your instrument repaired.
Survey meter calibration and repair keeps your meter operating at peak performance. ORS provides free calibration service for portable survey meters in University laboratories. We check switches, batteries and high voltage, use an electronic pulser to calibrate the various ranges, and check detector operation with a source of radiation. We provide a copy of the survey report and schedule another calibration for next year. Check the calibration sticker on your instrument; if it is missing or more than a year old, call ORS to arrange for calibration.
Common problems include shorting cables,
punctured tube windows, and leaking batteries. We've also seen meter
window glass fall out and knobs come off. While we can make some minor
repairs, in many cases we will help you get the parts or service you
need from the manufacturer. Make sure the meter has fresh batteries
before you bring it in.
Suppose you saw your doctor walk out of the
examining room wearing disposable gloves! Yuck! Gloves are barrier protection
against toxic chemicals, radioactive materials and pathogens encountered
in research and clinical settings and should not be worn outside the
lab. At the very least, wearing them outside the lab conveys the impression
that the wearer is more concerned about his/her personal safety than
yours. At the worst, the wearer is spreading hazards to unsuspecting
colleagues. No one should hand-carry items that are contaminated on
the outside into public spaces anyway. So, don't touch that doorknob
or elevator button or telephone with a gloved hand. Use sealed secondary
containers that are clean on the outside to transport materials, and
keep a spare pair of gloves in your lab coat pocket.
* These topics last were covered in NUtrino 18, June, 1999, and NUtrino 19, July, 1999.
Use this NUtrino as a training tool. Circulate it among the radiation workers in your group and have them sign and date the training form on the back. File it with your authorization and other radiation safety documents for review during regulatory inspections. Discuss it during laboratory meetings. We have back issues, or you can print them off the Web.