Yes. When a Principal Investigator is granted approval to use radioactive material by the Yale University Radiation Safety Committee, certain limits are authorized. The maximum amount to be ordered at in one day is stated as part of the approval. The maximum amount allowed to be in the possession of one Principal Investigator at one time is also stated. The total amount of radioactive material in all individual laboratory rooms used by that PI is summed. This total, including waste and experiments in progress in the labs, must not exceed the authorization limits. See your individual PI for information about the specific limits in your research group.