According to the NRC, decay in storage records must include the date that the radioactive material was?

The correct choice highlights that the records for decay in storage must include the date that the radioactive material was disposed of. This is an important aspect of regulatory compliance in nuclear medicine and radiation safety. The U.S. Nuclear Regulatory Commission (NRC) emphasizes maintaining accurate records to ensure that the handling, storage, and disposal of radioactive materials are conducted safely and in accordance with established guidelines.

In this context, having the disposal date recorded is crucial as it helps in tracking the material's lifecycle and ensures that any remaining radioactivity is properly managed following disposal. This also aids in compliance with regulations regarding the safe handling of radioactive waste, as disposal practices are governed by specific timelines and protocols to minimize exposure to personnel and the environment.

While the other options might seem relevant to the management of radioactive materials, they do not reflect the specific requirement for records regarding decay in storage, which focuses on the end-of-life management of the radioactive materials rather than their initial handling or usage.