Radioactive waste generated on campus is not to be discarded into the regular sanitary waste disposal system. Specific rules, regulations, and guidelines must be followed for the disposal of radioactive waste. Emphasis is placed on segregation of different types of waste according to radionuclide, half-life, chemical form, physical form, or combination thereof. Under the University’s radioactive materials license, radioactive waste with a half-life shorter than 90 days can be held for decay under the decay-in-storage program and safely disposed of as non-radioactive waste once the radioactivity levels have become indistinguishable from background levels. All other radioactive waste must be collected and packaged for disposal to an outside licensed disposal facility. Radioactive waste burial sites charge by the cubic foot, so all radionuclide users are asked to make a conscious effort to minimize the volume of radioactive waste generated in their laboratories. All radioactive waste streams need to have prior approval by the Radiation Safety Division before generation is started. The following guidelines are to be used in the disposal of radioactive waste.NOTE: Waste pickups are decayed to the original receipt date, not the date of pickup. Use the supplied waste forms for detailing all waste pickups.
NOTE: Waste will only be accepted in radioactive containers supplied by the UNM Radiation Safety Division.
A. Solid Dry Waste
Solid dry waste normally consists of absorbent pads, gloves, disposable labware, pipettes and other similar items contaminated with radioactive material. Solid dry waste must not contain liquids, sharps, lead pigs, scintillation vials (even empty vials), chemicals, or biologicals. Waste will be segregated by radionuclide and half-life; < 30 days, 30 to 60 days, 60 to 90 days, >90 days, and transuranics. If more than one waste category exists in a laboratory, the waste containers will be marked as to which radionuclides are to be placed into each specific container. Compliance with such markings is essential. Careful consideration should be given to external dose rates created by gamma and high-energy beta emitters placed into waste storage containers. It may be necessary to shield the material or make arrangements with the Radiation Safety Division for immediate pick-up.B. Aqueous Liquid Waste1. Important Items:
a. No liquids allowed. No liquids of any kind shall be placed in dry waste containers. All vials that contained liquids will be emptied and placed into solid dry waste with no lids attached.
b. No lead items. All lead shall be removed from dry waste and stored separately for pick-up.
c. No broken glass, loose needles or unprotected sharps. Such materials should be placed in a separate plastic container and stored separately for pickup.
d. No flammable, pyrophoric or water reactive materials.
e. No biological material.
f. No viable pathogenic or infectious agents.
g. No organic solvent contaminated items or items capable of generating toxic gases, vapors or fumes.
h. Waste must contain less than 0.1% by weight chelating agents.
i. All waste containers must have an indication of radionuclide and estimated activity.Aqueous liquid waste denotes any waste of which the primary solution is water and any soluble organic and inorganic constituents, all present in quantities and forms that do not result in phase separation or precipitation. Care must be taken to make sure that the quantities of organic or inorganic components added to the water do not make the mixture a mixed waste. Even small amounts of substances, when combined with non-hazardous materials, may result in a mixed waste. A solution containing as little as 6% methanol in water is a mixed waste. Consult with the Radiation Safety Division before adding any organic material to aqueous waste. Aqueous liquid waste will normally consist of aqueous phase extractions from experiments and the first rinsing of radioactive material containers.C. Liquid Scintillation Waste
1. Important Items:a. Do not put pipettes, pipette tips, vials, sharps, or filters into liquid waste containers.
b. Do not overfill the container.
c. The pH of aqueous wastes shall be adjusted as close to neutral as possible, a pH shall be within the range of 5 to 9.
d. No mixing with liquid scintillation fluids.
e. Waste must contain less than 0.1% by weight chelating agents.
f. All waste containers must have an indication of radionuclide, activity and percentage of non-aqueous material.Liquid scintillation (LS) waste is liquid waste, which usually consists of a xylene or toluene based scintillation fluid. LS waste is divided into two categories based on the radionuclides present and the average activity per gram of media:D. Biological Waste
- H-3 and C-14 waste with an average activity of less than 0.05 ?Ci per gram of media, and
- all other radionuclide LS waste.
Estimates of activity should be based on calculations from actual vial counting. An average of 0.05 ?Ci per gram of media amounts to about 250 microcuries per case of standard 20 millimeter vials (500 vials). It is very unlikely that activity concentrations this high are routinely used in normal laboratory procedures. Generators should be prepared to justify, with supporting calculations or printouts, elevated LSV waste activities. It is important to have a realistic assessment of activity in these wastes. Most LS waste will be generated in vial form. Special arrangements need to be made with the Radiation Safety Division for LS waste that is not collected in vial form.1. Important Items:
a. Vials containing H-3 and/or C-14 shall be segregated from other radionuclides.
b. Make sure vials are securely capped. When possible return vials to their original trays for waste pick-ups. Ideally vials should be kept vertical during collection and storage to avoid leakage.
c. If vials are collected in 5 gallon containers, insure vials are securely capped and carefully placed into container to prevent breakage.
d. All waste containers must indicate radionuclide, activity, and chemical percentages of waste.Biological waste primarily consists of animal carcasses, bedding, and excrement. It may also include specimens in vials or containers. Waste containing biological (excluding animal carcasses), pathogenic, or infectious material or equipment (e.g., syringes, test tubes, capillary tubes) used to handle such material, shall be treated to reduce, to the maximum extent practical, the potential hazard from the non-radioactive materials. Waste with a half-life less than 90 days needs to be segregated from other waste. Small animals may be bagged and kept frozen until the date of pick-up. Researchers working with large animals such as large dogs, sheep, or hogs must contact the Radiation Safety Division to make arrangements for disposal.E. Mixed Waste
1. Important Items:a. Animal carcasses, contaminated bedding and tissues must be placed in strong, tightly closed, leak-proof plastic bags. Bags must be placed in freezer until date of pick-up.
b. Separate waste with a half-life of < 90 days from longer half-life waste.
c. Needles and other sharps must not be placed in bags with animal carcasses.
d. Do not put non-biological materials into carcass bags. Collect paper, plastic, foil, syringes, and absorbents separately and treat, if necessary, to reduce non-radiological hazards.
e. All waste containers must indicate radionuclide and total activity per gram weight, averaged over the initial weight of the disposed animal.Mixed waste contains radioactive material and one or more hazardous chemical components. Most chemicals classified by the EPA as hazardous are regulated under the Resource Conservation and Recovery Act (RCRA). The hazardous waste can be either a listed hazardous waste (40 CFR 261, SubPart D) or a waste that exhibits any of the hazardous waste characteristics (40 CFR Part 261, Subpart C). Hazardous waste contractors will not accept a hazardous waste that contains radioactive material. Generation of a mixed waste often leaves the university with a waste with no disposal options. To avoid conflicts between disposal requirements avoid the generation of a mixed radioactive and RCRA hazardous waste. Any waste stream that involves the mixing of a hazardous waste with radioactive material must have prior approval from the Radiation Safety Division before generation.F. Uranyl/Thorium Compounds and Staining Solutions1. Important Items:
a. Mixed waste containing radionuclides with a half-life of 90 days or less will be held for decay by the Radiation Safety Division and disposed of in accordance with the hazardous material disposal requirements.
b. Mixed waste containing radionuclides with a half-life of >90 days half-life must be kept separate from all other mixed waste. Prior approval from the Radiation Safety Division is needed before generation of this type of waste is started.Dry Uranyl Acetate, Uranyl Nitrate, Thorium Nitrate and solutions containing concentration of these shall be collected and disposed of as radioactive waste. Never combine waste containing uranyl or thorium compounds with any other chemical waste, such as lead citrate. All waste generated must have recorded with it the total number of grams of uranyl or thorium compounds.G. Chelating Agents.The presence of high concentrations of chelating agents in radioactive waste may have an effect on waste-site stability. All waste containing chelating agents shall indicate the name and weight percentage of any chelating agents that are present in excess of 0.1% by weight. Chelating agents include amine polycarboxylic acids (e.g., EDTA, DTPA) and hydroxy-carboxylic acids (e.g., citric acid. carbolic acid, and gluconic acid) used for the purpose of binding (i.e. to stabilize radioactive materials).