1.    Radioactive Waste Disposal
2.    Mixed Wastes
3.    Procedures for the Disposal of Radioactive Waste
4.    Incidental Sink Disposal Log

Radioactive Waste Disposal

All radioactive waste is collected and managed by the Environmental Health and Radiation Safety (EHRS) Department.

Radioactive waste must be disposed of in accordance with regulatory requirements and license conditions. Several factors determine the route by which radioactive wastes are disposed. These factors include: half-life, radionuclide, chemical constituents, physical form (liquid or solid), dose rate, etc.

Most wastes that contain radionuclides with half-lives less than 120 days are disposed of by decay-in-storage.

• The minimum holding period for decay is ten half-lives of the longest-lived radionuclide in the waste. Such waste may be disposed of as ordinary trash or biohazard trash if radiation surveys of the waste at the end of the holding period indicate that radiation levels are indistinguishable from background.
• All radiation labels must be defaced or removed from containers and packages prior to disposal.
• Records will be maintained of the radionuclide, date the material was placed in storage, the disposal date, the final survey levels, and the type of material.

Solid radioactive wastes contaminated with radionuclides with half-lives greater than 120 days are disposed of through a contracted radioactive waste disposal service broker.

The following radioactive wastes may be disposed of as non-radioactive waste (deregulated waste):

• Liquid scintillation media (including vials and other items contaminated with liquid scintillation media) containing no more than 0.05 uCi of H-3 or C-14 per gram or per ml of the medium. [These liquids are collected by EHRS for disposal into a designated sink].
• Animal carcasses or animal tissure containing no more than 0.05 uCi of H-3 or C-14 per gram averaged over the weight of the entire animal. [These should be disposed properly as biohazard waste].

Certain liquid radioactive wastes (regulated waste) may be disposed of into the sanitary sewer system. All liquid radioactive waste is collected by EHRS for disposal into a designated sink. Radioactive liquid waste is strictly prohibited from being disposed of into laboratory sinks. (See Information on Incidental Sink Disposal)

• The quantity of radioactive material released into the sewer system must not exceed monthly and annual discharge limits.
• All materials must be aqueous and readily soluble/or dispersible in water.
• pH must be between 5 and 9.
• Accurate records must be maintained of all releases into the sanitary sewerage.

Mixed wastes are radioactive wastes which also contain hazardous waste components regulated under the EPA, Resource Conservation and Recovery Act (RCRA), and the State of Pa. Regulations. Currently, there are very few options for the disposal of mixed wastes, and the options which do exist are very costly.

The EHRS Department is available to help determine whether specific wastes meet the definition of mixed wastes. Whenever feasible, contact the EHRS Department before generating mixed wastes to allow time to determine disposal options or to establish procedures which may prevent a mixed waste from being generated.

Procedures for the Disposal of Radioactive Waste

All radioactive wastes are collected by the EHRS Department. Waste will only be collected if:

• Accompanied by a completed Radioactive Waste Transfer Form;
• Bags or containers have radioactive waste tags attached, labeled with the radionuclide, date, investigator, activity, and any other materials contained in the waste.
• Waste bags and containers must be sealed completely with tape, liquid waste container caps must be tightened. .
• Never mix short half-lived materials that can be decayed in storage (T1/2<120 days) with long half-lived materials, like H-3 or C-14. (H-3 and C-14 may be placed into the same waste container) In other words, separate all radionuclides except H-3 and C-14.
• Never mix EPA hazardous chemicals with radioactive waste. If unavoidable, contact the Environmental Health and Radiation Safety Department before generating these "mixed" wastes to allow time to determine disposal options. It is usually very costly.
• Radioactive liquid waste is strictly prohibited from being disposed of into laboratory sinks. However, the washwater from the rinsing of your glassware, etc. may be put into the laboratory sink, if it is less than 0.1 uCi. However, this must be recorded on an "Incidental Sink Disposal Log" posted by the sink. If activity is greater than 0.1 uCi, collect 1st rinsate into a liquid waste container. Collect liquid waste in proper plastic polyethylene containers available in the Griffith Hall and McNeil Science and Technology Center stockrooms. Tags labeling it as radioactive, with the radionuclide(s), approvimate activity, and other constituents, must be attached while the waste is accumulating and while it is stored in the laboratory. Additionally, all liquid waste must be stored in a secondary container (tub) while stored in the laboratory.
• Dry solid radioactive wastes (usually gloves, paper towels, non-rigid plasticwate, glassware) should be stored in the radioactive labeled boxes containing a yellow radioactive labeled plastic bag, inside a thick 4 mil clear plastic bag. The cardboard boxes must indicate the radionuclide(s). Do not place anything into a yellow radioactive labeled plastic bag that may break through the bag. (i.e., needles, pipettes, slides, any sharps) Yellow sharps containers marked with the radioactive materials label should be used. (Yellow sharps containers may be ordered through the Central Stockrooms) No liquids may be placed into yellow radioactive labeled plastic bags. However, small containers with residual liquids are permitted if the waste also contains sufficient material to absorb twice the volume of the liquid. (Vermiculite poured into the bottom of the bag should be used for this purpose and may be obtained from the Griffith Hall Central Stockroom.)
• Radiation Only-Contaminated Sharps (i.e., pipettes, needles, slides, needles, syringes, rigid plastic, glass plates, etc.) must be placed in a yellow sharps container of sufficient strength and marked with the radioactive materials label. (Yellow sharps containers may be ordered through the Central Stockrooms.) By law, needles whether contaminated or not, must always be placed into a sharps container.
• Liquid infectious wastes that contain radioactive material must be rendered biologically inactive before the EHRS can accept it. You may disinfect with 1 part bleach to 10 parts liquid, or with another appropriate disinfectant. However, never use bleach with radioactive iodine (I-125) or sulfur (S-35) as it can cause volatilization. Additionally, do not use hot water, acids, or acid detergents with I-125 because volatile iodine may also be produced. Contact EHRS for storage and disposal procedures of solid infectious wastes that contain radioactive material.
• Used liquid scintillation fluid in vials may be consolidated into sealable plastic polyethylene containers and stored in secondary containment (tubs). Tags labeling it as radioactive, with the radionuclide(s), approximate activity, and other constituents, must be attached while the waste is accumulating and while it is stored in the laboratory. Otherwise, the vials may be stored in cardboard flats designed to hold the vials upright with each vial tightly sealed. Tape the completed radioactive waste tag to each cardboard flat. Only non-hazardous (no toluene, xylene, etc.) scintillation cocktails shall be utilized. Also, only scintillation vials containing <0.05 uCi/ml of C-14 or H-3 or scintillation vials containing radionuclides approved for decay-in-storage (T1/2<120 days) are approved on our license for research.

No research is presently approved which may generate the following waste categories:

Radioactive animal carcasses;
Scintillation vials containing >.05 uCi/ml of C-14 or H-3;
Scintillation vials containing radionuclides not approved for decay-in-storage.

Incidental Sink Disposal Log

Although radioactive liquid wastes (deregulated or regulated) are prohibited from being disposed of into the drains in the individual laboratories, incidental amounts of radioactive wash water is allowed. (i.e., The first rinse of your container if  < 0.1 uCi)

However, this washwater must be recorded on an Incidental Sink Disposal Log.  The form should be posted near your designated radioactive sink. Activities recorded are your best estimate.  

If activity is greater than 0.1 uCI, collect the 1st rinsate into a liquid waste container.

(See Information on Chemical Waste Disposal)

(See Information on Biohazardous Waste Disposal)