address the general requirements for handling waste in a radioactive
laboratory. There are three different
types of radioactive waste created in a radiation laboratory: 1) purely radioactive, 2) mixed (radioactive
and chemical), and 3) radioactive and biological. Proper
handling of wastes is critical for
appropriate transportation and disposal.
Numerous Federal, State, and local regulations impact waste; the
Colorado Department of Public Health and Environment (CDPHE), the
Transportation (DOT), the Environmental Protection Agency (EPA) through
Resource Conservation and Recovery Act (RCRA), the University’s
Materials License, and the City of
Radioactive wastes are separated by waste type (solid, liquid, and scintillation vial) and by half-life. See section 2 of this chapter. Health Physics provides containers for all radioactive waste. When the containers are full, the laboratory submits a Radioactive Waste Pick-up Request Form to Health Physics. Health Physics then schedules a waste pick-up. See section 5 of this chapter.
Mixed waste is separated by waste type and half-life in the same way as purely radioactive waste. Generation of mixed (hazardous and radioactive) wastes should be avoided whenever possible. Disposal of this type of waste is very difficult and costly. Laboratories should actively seek ways to reduce the amount of mixed waste generated. One example of a way to decrease a laboratory's mixed waste production is switching to biodegradable scintillation cocktail from flammable scintillation cocktail.
Mixed waste generators must complete Hazardous Waste Generator Training as well as Radiation Safety Training. Please refer to the EH&S Generator’s Guide to Hazardous Material/Waste booklet for more information regarding the Hazardous Waste Generator Training. Please refer to the Training chapter for more information regarding Radiation Safety Training. On-line training is available at http://ehs.colorado.edu.
Generation of biological wastes mixed with radioactive material also should be avoided whenever possible. Any biological material must be rendered non-infectious using bleach or other disinfecting agent prior to disposal with Health Physics. When radioactive material is involved, use of an autoclave is NOT permitted. Once rendered non-infectious, this waste should be segregated from all other radioactive wastes. Do not use biohazard bags for radioactive materials. If this type of waste is expected to be produced in the laboratory, contact Health Physics at (303) 492-6523 for further guidance.
Radioactive waste is separated into three types: solid, liquid, and scintillation vials. Each type has specifically designated waste containers. Solid waste containers are available in two sizes, a twenty-gallon size which looks like a trash can, and a five-gallon size which looks like a covered metal bucket.
Liquid radioactive waste containers are available in two sizes, a five-gallon, round plastic carboy not to be confused with the cube-like carboys used for chemical wastes, and a one-gallon, round plastic bottle. Smaller containers are available upon request for small amounts of liquid waste. Secondary containment tubs are available from Health Physics and are strongly recommended for liquid waste containers.
Scintillation vials have only one size of waste container, a five (5) gallon covered metal bucket. This container looks the same as the small solid waste container. Care must be taken to avoid confusion between these containers. See section 4 of this chapter.
Containers are also provided for sharps, lead pigs, and any other unusual wastes. Empty lead pigs are stored separately and collected upon request by Health Physics for possible recycling. Unlike lead pigs, plastic pigs may be disposed in the appropriate solid waste container. Call Health Physics at (303) 492-6523 for special containers.
Radioactive waste is also segregated by half-life. There are three half-life categories designated by color. The half-life categories are as follows:
Rb-86 and other radionuclides with half-lives < 60 days
Orange: S-35, I-125 and other radionuclides with half-lives > 60 days but < 90 days
Green: H-3 and C-14 and other radionuclides with half-lives > 90 days
The yellow and orange categories are held for decay by Health Physics. Half-life categories are very important for waste minimization and decreasing disposal costs for the University. Waste should be segregated by half-life category whenever possible and placed in the properly colored waste container. If waste is created containing two or more isotopes from different half-life categories, the waste should be disposed in the container for the longest lived isotope in the waste. For example, waste containing S-35 and C-14 should be placed in a C-14 waste container.
Waste containers should be kept closed at all times, unless waste is actively being added to them.
Keep in mind the following restrictions when disposing of radioactive waste:
Each waste container having waste items in it should always have a completed waste Container Contents Sheet. Refer to Appendix I for a blank Container Contents Sheet. The Container Contents Sheet is required by regulations. An entry should be made on the sheet each time that waste is placed into the container. The entry should detail the amount added, constituents, radionuclide and activity, and the initials of the waste generator. Full chemical names, in English, should be used for each constituent. Please do not use abbreviations.
Container Contents Sheets are provided with each container from Health Physics and are normally color coded to correspond with the decay categories used to separate waste by half-life. The color copies were implemented to facilitate identification with a given container in laboratories having multiple decay categories. If you need additional Container Contents Sheets, copies are acceptable, color coding is not required. Additional copies are available from Health Physics as well.
When the container is full, the individual entries from the waste generators should be totaled and the separate total section of the Container Contents Sheet should be completed by an appropriately trained waste generator. Prior to pick-up by Health Physics, the waste generator must survey the exterior of each container for contamination using a wipe smear and liquid scintillation counter analysis. The results of the wipe smear survey should then be recorded on the container contents sheet. Each sheet also must be signed by the generator. The Generator Certification is required by regulation and includes confirmation that the generator has completed radiation safety training. Please refer to the Training Chapter.
When some or all of the waste containers in a laboratory are full, a pick-up may be requested from Health Physics. To request a pick-up, the generator or laboratory representative completes a Radioactive Waste Pick-up Request Form. Requests must be submitted to Health Physics any time before on the day preceding the next scheduled pick-up. The pick-up request forms may be submitted in person, by Fax, Campus Mail, U. S. Mail, or on-line at http://www.colorado.edu/radsafety. Refer to Appendix J for a blank form. Contact Health Physics at (303) 492-6523 for a current waste pick-up schedule. The Radioactive Waste Pick-up Request Form summarizes all of the information for the containers that need to be collected including the total volume of the container, radionuclide, total activity, constituents and total percentages of each constituent (which must total 100%), and pH for liquids. Indicator paper is acceptable for determining the pH value. Unless otherwise requested, each container collected will be replaced with an empty container of the same type and size.
When the Radioactive Waste Pick-up Request Form is submitted, each Container Contents Sheet must be completed, signed by the generator, and the contamination survey performed and noted on the sheet. Health Physics cannot collect waste containers without properly completed container contents sheets.
Sealed sources require special provisions for disposal. A completed Container Contents Sheet and Radioactive Waste Pick-up Request Form will be required as mentioned in sections 4 and 5 of this chapter. Contact Health Physics at (303) 492-6523 to dispose of sealed sources.
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Radiation Surveys Training