If your facility is licensed to work with radioactive material, at least one sink was designated for radioactive waste disposal when the license application was submitted. This sink should be posted and a log to track the radioactive material disposed of down the drain should be maintained. These are very basic facts, but is anyone checking those sink logs?
The sink logs, which are completed by the approved user each time they dispose of radioactive material down the drain, should be checked on a regular basis by a member of your safety team. A sink calculation to determine the allowable daily discharge of the isotopes in use must be conducted, and the limits should be clearly posted by all sinks designated for radioactive waste disposal. On a monthly basis, it would be prudent to walk through the use areas and check all of the logs to verify that the daily discharges are within these set limits. Reviewing the log for compliance is important, and it will also keep you updated on the sink disposal practices. As research evolves, there may be a need to modify the sink calculations to increase the allowable daily discharge of one isotope in use, and decrease a limit for an isotope no longer being actively used.
Do not just put up a sink log to track disposal, and never verify compliance. Be proactive in reviewing the logs to keep updated on the program and verify compliance.