32 Ill. Adm. Code 351.1020
Storage Precautions
Section 351
Section 351.1020 Storage
Precautions
a) Each source of radiation, except accelerators, shall be
provided with a storage and/or transport container. The container shall be
provided with a lock, or tamper seal for calibration sources, to prevent
unauthorized removal of, or exposure to, the source of radiation.
b) When in storage, sources of radiation shall be isolated from
flammable or explosive substances.