The Committees of Duke University and Duke University Medical Center have adopted a number of policies and procedures to ensure the proper procurement, distribution, use and disposal of radioactive material and radiation-producing equipment. This chapter outlines important general radiation safety practices and procedures that must be implemented by all Authorized Users.
All Authorized Users are responsible for strict adherence to standard radiation safety practices and procedures in their individual laboratories and clinical areas. The Radiation Safety Division will assist Authorized Users in developing satisfactory written procedures pertinent to their specific requirements. In general, the following guidelines regarding the safe storage, control, and use of radioactive material will apply.
Each Authorized User shall:
When an Authorized User ends his/her affiliation with Duke University or desires to terminate his/her radiation license, any laboratory space controlled by that user must be decommissioned (cleaned out by the Authorized User and checked by the Radiation Safety Division) before the area can be returned to non-radiation use or occupied by another Authorized User. Any Authorized User who anticipates terminating his or her Authorization shall notify the Radiation Safety Officer of the termination in writing or via electronic mail no less than thirty (30) days prior to the anticipated date of termination.
The specific contamination survey requirements for each laboratory are outlined in the authorization documentation of the responsible AU. Laboratories using low-energy (<250 keV) beta emitters (e.g. 3H [tritium], 14C, 35S) and other nuclides as specified by the Radiation Safety Officer must perform periodic removable contamination (wipe) surveys. Records of these surveys shall be available for review by Radiation Safety Division personnel. The frequency of the wipe surveys will depend upon the materials being used in the individual laboratories, as specified in the written procedures for each laboratory and approved by the Radiation Safety Division.
The responsible AU must ensure that areas producing wipe test results in excess of the action limits specified in Table 2 are decontaminated. When documenting the results of wipe tests, the removable activity should be expressed in net disintegrations per minute (DPM) in an area equal to 100 cm2.
Table 2. Action Levels for Laboratory Contamination
| Net DPM on wipe* | Action to be taken by laboratory personnel |
| less than 220 | No action required |
| 220-11,000 | Clean area (see "Decontamination" below); repeat wipe(s) |
| 11,000-110,000 | Clean area; repeat wipe(s), notify RSO to verify clean-up |
| >110,000 | Cease radioactive material use. Notify RSO. Commence immediate cleanup under RSO supervision. |
* Wipe area 100 cm2 minimum.
Preparations for decontamination shall begin promptly. The user will determine the extent and hazard of contamination prior to commencing clean up. The individual responsible for the contamination is expected to perform the necessary clean up. The AU shall inform the Radiation Safety Division of all contamination incidents exceeding the notification level specified in Table 2 above. The Radiation Safety Division will oversee the associated decontamination process.
Procedures that might produce airborne radioactivity shall be conducted in a hood, glove box, or other suitable closed system. Such airborne radioactivity hoods must undergo an annual certification of airflow.
The air concentrations of radioactive material due to potential discharges from fume hoods or the accelerator facilities will be evaluated by the Radiation Safety Division. Where indicated, appropriate control methods such as activated charcoal filters will be employed to ensure regulatory compliance.
The administration of radioactive material to research animals and the irradiation of research animals must be approved by the Institutional Animal Care and Use Committee and the Radiation Safety Division.
Research laboratories must submit all radioactive material orders to the Radiation Safety Division using the web-based ordering facility specified by the Radiation Safety Officer (see the Radiation Safety Web Site for details). Clinical areas (Radiation Oncology, Nuclear Medicine, etc.) may order directly from the supplier.
Clinical areas (Radiation Oncology, Nuclear Medicine, etc.) may receive radioactive material directly from the supplier. All other shipments of radioactive material shall be addressed to and received at the centralized location designated by the Radiation Safety Officer. Contact the Radiation Safety Officer for any special case requiring an exception to this policy. Also contact Radiation Safety if anyone other than Radiation Safety staff deliver radioactive packages to the laboratory (except for the exceptions noted above). Radiation Safety will accept in-coming radioisotope shipments only during normal business hours Monday through Friday, excluding holidays. An Authorized User requiring radioactive material delivery outside of regular hours must contact the Radiation Safety Division in advance to make special arrangements.
Radiation Safety staff will deliver radioactive material only to the requesting Authorized User or their designee. Upon receipt, the Authorized user is responsible for ensuring completion of the following tasks:
Authorized Users shall complete their Radioisotope Inventory Reports within the intervals specified by the Radiation Safety Officer. The Inventory Reports must also include the amount(s) of radioactive material discharged into the sanitary sewer, if any.
Radioisotope Inventory Reports shall be submitted to the Radiation Safety Division using an on-line (Web-based) Radioactive Materials Inventory Reporting System that is maintained by Radiation Safety for that purpose. Radioactive materials shipments will be entered into the Inventory Reporting System by the Radiation Safety Division upon delivery. Authorized Users will be responsible for using the system to periodically update their holdings. Failure to update holdings within the maximum time intervals specified by the Radiation Safety Officer may result in suspension of ordering privileges or withholding of material. Acceptable time intervals for submission of inventory updates for unencapsulated and encapsulated radioactive materials will be stated on the Web site.
Transfer of radioactive material between Authorized Users, or between a User and an outside facility, are permitted as long as such transfers are in compliance with Duke University's license conditions and any other applicable regulatory requirements. Transfer of radioactive material to another institution requires an NRC or Agreement State license to possess that material by the receiving institution, and oversight by the Radiation Safety Officer of the receiving institution. The Radiation Safety Division must be notified before any transfers take place, either between Duke Authorized Users or with outside facilities.
The transportation or shipment of radioactive material on campus and to other institutions, including the Duke University Marine Laboratory, Duke laboratories in the Research Triangle Park and the Durham Veterans Affairs Medical Center, must comply with both State of North Carolina and United States Department of Transportation (USDOT) regulations. Unless specifically exempted by the Radiation Safety Officer, all radioactive shipments and transport within or from Duke University must receive prior approval from Radiation Safety. In addition:
Radioactive material, in any amount, must always be disposed of as radioactive waste and never placed in the normal solid waste stream. Small amounts of radioactivity may be discharged into the sanitary sewer (i.e. sink drain) in the course of cleaning glassware and laboratory apparatus. However, discharge to sewer should not be used as a primary means of radioactive waste disposal. Instead, liquid waste should be handled as described below. Authorized Users shall record, via their monthly inventory report, their discharge of radioactive material into the wastewater stream.
The Environmental Programs Division of the Occupational and Environmental Safety Office handles radioactive waste management for Duke University and Medical Center. Radioactive waste is collected in waste barrels provided by Environmental Programs. Authorized Users are responsible for ensuring that all their personnel working with isotopes understand the waste segregation and packaging procedures. Direct questions to the Environmental Programs Division at (919)684-2794 or env.progs@mc.duke.edu.
Segregate radioactive waste by physical form (dry solids, aqueous liquids, animal carcasses, scintillation vials, mixed wastes, and lead containers) and, within some of the physical forms, by half-life as follows:
Green: half-life < 30 days, i.e. 32P, 33P, 131I, and 51Cr.
Yellow: half-life between 30 days and 90 days, i.e. 125I and 35S.
Blue: half-life > 90 days, i.e. 3H, 14C, and 45Ca
Green: half-life < 30 days, i.e. 32P, 33P, 131I, and 51Cr.
Yellow: half-life between 30 days and 115 days, i.e. 125I, 35S, 113Sn
Blue: half-life > 115 days, i.e. 3H, 14C, and 45Ca
Dry solids consist of sharps, paper, plastic, glass, metal (not lead), and other assorted laboratory wastes without significant liquid content. Collect waste by half-life category and seal in plastic tear-resistant disposal bags provided by the laboratories. Remove excess air in plastic bags before sealing to minimize volume. Seal these bags with tape or twist tie and place them in a dry waste barrel lined with a second sealed bag (provided by OESO). Collect sharps (e.g. needles, razor blades, Pasteur pipettes, and broken glass) in a puncture resistant (sharps) container; the sharps container may then be placed in a dry waste barrel. Sharps containers must also be sealed in a plastic bag to control contamination. Sharps containers are available at the stockrooms and may be placed in dry waste or carcass barrels.
For laboratories using isotopes from only one half-life category or with extra space to accommodate multiple barrels, an alternate procedure (consolidated waste) eliminates the extra packaging of dry waste. These laboratories are allowed to use a separate barrel for each half-life category and may directly add dry waste to the barrel without packaging it separately first. However, when the barrel is full, the plastic bag lining the barrel must be sealed and labeled according to the procedures described under VII.D.6.c and VII.D.6.d.
Aqueous liquids are solutions involving water as the only solvent, with pH between 3 and 10. Radioactive aqueous liquids must be collected in plastic containers (with size appropriate to the quantity generated) by half-life category and sealed with lids such that the liquids will not leak. The OESO provides one-gallon plastic containers for liquid disposal but will allow laboratories to use other containers that meet approval with Radiation Safety and Environmental Programs personnel. The one gallon liquid waste containers provided by the OESO can be filled to a level no higher than four inches below the mouth of the container and must remain in an upright position at all times. These containers can be obtained at the Nanaline Duke Stockroom. Each collection container must be maintained in a catch basin capable of holding the total volume of liquid in case of leakage or spillage. Small amounts of liquids can be discarded in sealed tubes with dry waste as long as the volume of liquid does not exceed 25 milliliters for the entire barrel. Potentially contaminated gloves worn during procedures must be removed and treated as dry waste. Note: The use of clay absorbent is prohibited.
Radioactive animal carcasses and their associated bedding, excreta, tubes, etc. must be bagged and sealed in 3 mil plastic bags (Baxter catalog number 8825, Convertors® Gusset Tubing Bags are recommended for large carcasses). Sharps must be collected in sharps containers and be disposed of as dry radioactive waste. Sharps containers are acceptable in carcass barrels, as long as they are not contained within the same bag as the carcass. If possible, do not put more than 50 pounds of material in a bag. Waste packages are then labeled with radioactive tag, labeled with a barcode label color-coded for the appropriate half-life category and refrigerated in a lined 30 gallon plastic drum (all provided by OESO).
Authorized Users are encouraged to investigate and implement the use of biodegradable liquid scintillation fluids. These materials are typically non-toxic, have high flash points and do not require a fume hood for storage or use. Compared to toluene-based scintillation fluids, biodegradable "cocktails" are less hazardous and can contribute significantly to efforts to reduce the volume of radioactive waste. Scintillation vials should be collected in containers provided by OESO. Before vials are placed in a waste container they must be removed from the carton and have all the caps tightened. Scintillation vials do not have to be segregated by half-life categories. Vials containing biological material must be handled as carcass waste, due to their tissue content. In-vitro vials can be handled as dry waste.
For the purpose of this policy, mixed wastes are those wastes that contain both radioisotopes and hazardous chemicals. Refer to the Chemical Waste Procedure for Duke University/Medical Center for the definition of Hazardous Chemical Waste. Laboratory personnel must determine if the waste generated by an experiment would be classified as a mixed waste. Examples of mixed waste include: tritiated benzopyrene in ethyl acetate, 32P labeled GTP in chloroform, and 14C labeled acetic acid.
There can be no generation of mixed wastes without the prior written approval of the Environmental Programs Division. NOTE: This requirement specifically excludes solvent based scintillation cocktail fluids used for scintillation counting.
Written approval will typically be given for:
Lead is a hazardous waste regulated by the United States Environmental Protection Agency (EPA) and cannot be discarded in the regular trash or with the radioactive waste. However, it can be recycled. Laboratories have two options for recycling of their lead shielding containers (pigs). These lead pigs can be collected in boxes and returned to the manufacturer, New England Nuclear (NEN), or the pigs can be collected in reusable containers provided by OESO for manufacture of lead bricks for shielding. The details are:
Contact the Environmental Programs Division if you will be creating any radioactive waste that does not fit any of the above categories.
Each waste barrel submitted for disposal must be accompanied by a waste disposal sheet for documenting the half-life category, nuclide(s), activity, and the date each bag of waste was added to the barrel. There are different sheets for dry waste, liquid waste, carcasses and scintillation vials. Please ensure that the sheet matches the physical form of the waste. Laboratories are responsible for keeping an original blank copy of these forms to make photocopies for new waste barrels. The laboratory is also responsible for retaining a copy of the completed form for inventory purposes.
Each bag of waste placed in the barrel must be packaged according to the specifications listed in VII.D.6.b. In addition, each bag must be labeled with the appropriate color-coded barcode label for its half-life category with the matching label placed on the waste disposal form. Note: Treat mixed isotopes as the longer-lived isotope, but document both isotopes and their activity on the disposal form.
For consolidated wastes (all isotopes in the same half-life group) the bag lining the waste barrel is the collection bag. The laboratory must seal this plastic bag with tape and attach one barcode label, color-coded for the appropriate half-life category, on the outside of the bag. This barcode label should be readily visible to the technicians upon pick-up. The matching barcode label must go on the waste collection sheet for that barrel. If there are multiple sheets for one barrel, there must be one barcode label for each sheet accompanying the waste barrel. The waste disposal form must be filled out for each addition to the barrel. The waste disposal form must be kept on or near the barrel to provide a current inventory of the barrel contents.
If a laboratory has properly packaged the waste, upon pick-up the OESO technician will sign and retain the disposal form for each barrel that is removed. Laboratory personnel are responsible for providing a blank disposal form for all new barrels.
Laboratory personnel in each work area will be responsible for requesting pickups of their radioactive waste. Requests are made by calling the radioactive waste pickup line at (919)684-3210. Pick-ups will occur within one business day of a request (this excludes weekends and Medical Center holidays); however, waste containers will not be removed if forms lack the appropriate information or the waste is packaged incorrectly. The technicians will notify laboratories of any problems with the waste or disposal forms when they occur. If the laboratory has questions or needs to solve a waste related problem, they should call Environmental Programs staff at (919)684-2794.
Because of differences in shielding and handling requirements, Environmental Programs processes hot barrels differently than standard pickups. Environmental Programs defines a hot barrel as any barrel for which the exposure rate is greater than 2 mR/hr as measured at one meter from the unshielded barrel.
To have a hot barrel picked up, Environmental Programs must be notified 24 hours in advance. Call (919)684-2794 and ask for the radioactive waste manager. We will need to know the isotope, activity, waste type, and number of barrels. You will be given a 2 hour time window during which the waste will be picked up the following workday. Additional information on OESO policy on radioactive waste can be found in the Radioactive Waste Section of the Duke University Safety Manual.
| Top of Chapter | Next Chapter | Manual Home |