Section 5: Radioisotope Safety Regulations and Policies

The Commonwealth of Massachusetts has established regulations to control the use and licensing of radioactive materials and nuclear facilities. The principal regulations on which this Manual is based are provided in 105 CMR 120.00, entitled “Massachusetts Regulations for the Control of Radiation” which are based on the federal regulations 10 CFR Part 20 “Standards for Protection Against Radiation”. Institutions and individual radioisotope users must comply with the applicable requirements of the state regulations.

In addition to this Manual, BU and BMC (BU/BMC), as licensees for the possession and use of radiation sources, recognize their responsibility to evaluate, approve, and establish appropriate policies and procedures for the safe use of radioisotopes and radiation sources. To this end, both institutions appointed the RSO and RSC to evaluate new policies, procedures, or other proposed changes to the radioisotope program.

The guidance established in this Radioisotope Manual shall be followed by all radioisotope users at BU/BMC. Any variance must be reviewed and approved by the RSO.

A radiation source is any radionuclide, X-ray machine, accelerator or other device capable of emitting hazardous ionizing radiation and its use is subject to RSC oversight. Hazardous ionizing radiation is any particulate or electromagnetic radiation capable of producing biological damage through the ionization of an atom.

BU/BMC users shall conform to the safety limits specified in Massachusetts regulation 105 CMR 120 regarding the total radiation exposure allowable in one calendar year. Here, a person’s radiation exposure is referred to as the Total Effective Dose Equivalent (TEDE): the total external and internal doses to an individual, given in units of rem (a formal definition of TEDE is provided in 105 CMR 120.105). Often times a radiation exposure is small enough to be given in terms of millirem (mrem) where 1,000 mrem is equal to 1 rem. Table 1 below presents a Section 5 summary of the maximum radiation exposures (in units of rem/year) that a radiation user is allowed to receive in a single calendar year. While the exposures in Table 1 present the legal limit that a radiation user may receive, BU/BMC strictly adhere to the ALARA principle requiring users to minimize their radiation exposures (see ALARA, Section 2).

Table 1: Occupational Effective Dose Equivalents Limits (rem/year)

BU/BMC have set an administrative limit for the total effective dose equivalent at 375 mrem/quarter. Exemptions to this administrative limit may be granted by the RSO or their designee for specific projects on an as needed basis. Radiation sources normally encountered at BU/BMC are not expected to cause doses above this administrative limit. In fact, exposures are expected to be well below this limit. In addition, members of the public are limited to no more than 0.1 rem/year and 0.002 rem in any one hour from radiation related activities performed at BU/BMC.

To maintain public safety and meet relevant state and federal regulations, all radioisotopes are controlled for the lifetime of the source. Therefore, the BU/BMC Radiation Safety Program has set forth the following controls:

1. Any space or laboratory in which radioisotopes are to be used or stored must first be authorized by the DMPRS/RSO and RSC for the intended use and a PH must accept responsibility for implementing the requirements of this manual.
2. Ordering and purchasing radioisotopes is controlled through the DMPRS. Individuals wishing to purchase a radiation source must comply with Purchase of Radioactive Materials and Devices of this manual.
3. The use or storage of radioisotopes within a laboratory must comply with the conditions and standards presented in Working with Radioactive Materials and Devices of this manual.
4. Disposition of radioisotopes (shipping, or waste handling) must comply with the requirements of Radioactive Waste Management and Disposition of Radioactive Materials and Devices of this manual.