Control and Security of Radioactive Materials

The MU RSP exists to provide safe work conditions and to meet the regulatory requirements in the control and security of RAM.  In order to ensure control and security of radioactive materials, the following policy is implemented:

  • Prudent laboratory practice appropriate for the non-radioactive work in the laboratory (e.g., NIH and CDC Biosafety in Microbiological and Biomedical Laboratories; Prudent Practices for Handling Hazardous Chemicals in Laboratories; ACS Safety in Academic Chemistry Laboratories) will be followed. 
  • Radioactive materials shall be secured from unauthorized removal or access. 
  • Food and drink shall not be stored or consumed, nor should cosmetics be applied, in the restricted area unless RAM is in the form of sealed sources and no other hazards are present.
  • The restricted area shall include the entire laboratory area (includes rooms to which access can only be made through the laboratory) bounded by walls and a lockable door. 

The Radiation Safety Committee also provides an approved policy regarding the security of RAM and follow-up actions for security violations on the RSC Security Policy page. 

AU’s are responsible for the security of all RAM in their possession including radioactive waste in storage.  NRC regulations allow for the use and storage of radioactive materials in two types of areas:



Transient use areas are areas where radioactive materials are used for infrequent and short periods of time (<8 hours).  All materials must be secured by physical means or by maintenance of a constant line-of-sight. At the end of each work period a documented survey must be performed to confirm that contamination is not present.  These areas do not require posting.  Additional or different conditions may be outlined in the individual authorization.



Restricted Area is any area to which access is controlled by the licensee for purposes of protection of individuals from exposures to radiation and radioactive materials (e.g., labs approved for use or storage of radioactive material). 

Areas where radioactive materials are routinely used or stored are usually designated as restricted areas.  Such areas must have two conspicuous signs at each entryway: first, “RESTRICTED AREA”; and second, “NO EATING, DRINKING, OR SMOKING”.  AU’s may also request the sign, “AUTHORIZED PERSONNEL ONLY”.  If the area is required to be posted because of the amount of radioactive materials, the conventional radiation caution symbol and the words “CAUTION RADIOACTIVE MATERIAL” must also be posted at each entryway.

AU’s are responsible for security of their areas.  If the restricted area is required to be posted for radioactive material, the restricted area must be supervised when unlocked, or the radioactive material (stock, samples and waste) must be locked up or otherwise secured from unauthorized removal.

Certain restricted areas which contain very large quantities of radioactive materials may require additional security measures beyond these listed.



Unrestricted Area = access to facilities not controlled for radiation protection.

Controlled Area = access to facilities controlled for any reason deemed necessary by MU.

All licensed materials that are stored in unrestricted or controlled areas must be secured from unauthorized removal from the place of storage.  Such areas include locked and labeled “CAUTION RADIOACTIVE MATERIAL” refrigerators, freezers, or cabinets in hallways.

All licensed materials that are not in locked storage in unrestricted or controlled areas, must be under constant surveillance and immediate control of an approved RW or AU at all times.

Radiation levels in unrestricted areas shall be such that no member of the public has potential to exceed 2 mRem in any one hour or 100 mRem/yr

NOTE: Anyone who suspects that radioactive material has been lost or stolen shall contact the RSS immediately.

Posting requirements defined in the regulations can be found in 10 CFR 20.1902. MU specific posting requirements can be found in Posting and Labeling.


Page last updated on June 7, 2019.