Edition 18, June 1999

Radiation Safety Monthly Focus: Intermediate or Casual Radwaste Containers

Our Monthly Focus for June concerns those small containers you use to collect radioactive waste at your benchtop. You know, the trash can, the cardboard box, or the plastic bag that is more convenient than hauling the waste over to the radwaste can or moving the radwaste can over to the bench. This issue came up during last year's inspection, when a radiation worker was observed dropping potentially contaminated gloves into a trash can. Although the radiation worker was the only one working in the lab and was using it merely as a transfer container, the inspectors decided there were several things wrong with that. First, the can did not have a label identifying the contents as radioactive. Second, it was not a standard radwaste container, which itself is not prohibited but caught the eye of the inspector. Third, it was nicely lined with an orange biohazard bag, which is not permitted for radioactive waste.

The fundamental problem is that no one else knows what is in that unlabeled container. The radiation worker could walk away and someone could move it to another part of the lab. A custodian could empty it into a trash bin (you can imagine the pleasures of dumpster diving with a survey meter looking for that 250 microcuries of P-32). And, perish the thought, someone could put that orange bag into the autoclave and contaminate the autoclave.

The rule about labeling radioactive waste containers is spelled out in section 22.9 of the Radiation Safety Handbook: "Each container of radioactive waste shall bear a label or tag identifying the contents at all times; identifying the nuclide in the container is essential." 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 (such as a trash can) for another purpose, it has to be surveyed and documented as clean before reuse. Better to use one of our standard containers in the first place.

Of Continuing Interest:

Operational checks of radiation survey instruments are important because they will tell you whether your survey meter is functioning correctly before you use it. The best way to check it is with a small, long-lived check source counted in the same geometry each time. Other sources can be used such as the thorium lantern-mantle and the Fiestaware( plate. Finally--and we have it on good authority that this is OK to do in a pinch--you can aim the detector at a known source of activity (say, one of your stock vials) and see if you get a response. If you don't get a response, 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.