2. Mixed Wastes
for the Disposal of Radioactive Waste
4. Incidental Sink Disposal Log
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,
Most wastes that contain radionuclides with
half-lives less than 120 days are disposed of by decay-in-storage.
- The approximate 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 (surface readings) of the waste
at the end of the holding period indicate that radiation levels are indistinguishable
- Survey the contents of each container in a low background area.
- 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,
the type of material, survey instrument used and the initials of the individual performing the surveys.
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) only by the EHRS Department:
- 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 tissues 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. Liquid radioactive
waste is collected by EHRS for disposal into a designated sink. Radioactive
liquid waste is prohibited from being disposed of into laboratory sinks.
(See Information on Incidental Sink
- 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
- 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. 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. Unfortunately, due to the high cost for the disposal of mixed
wastes, the cost will need to be paid by the researcher generating
for the Disposal of Radioactive Waste
- All radioactive waste being accumulated or stored
in the laboratory must be in labeled containers that have a "Caution
Radioactive Materials" label or tag attached and that indicate the isotope(s) contained in the waste. Liquid waste should also indicate approximate activities and any other constituents in the waste.
- Radioactive liquid waste is
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 or equal to 0.1 uCi. However,
this must be recorded on an "Incidental Sink
Disposal Log" posted by the sink. (Liquid washwater being
discharged into the sink must be soluble and readily dispersible in water.)
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),
approximate 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 waste (e.g., usually
gloves, paper towels, non-rigid plasticware, gauze/bandages) 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,
rigid plastic, glassware, any sharps) Yellow sharps containers marked
with the radioactive materials label should be used. (Yellow sharps containers
are available in the Central Stockrooms.) No liquids may be
placed into yellow radioactive-labeled plastic bags. However, small
containers with trace liquids are permitted if the waste also contains sufficient
material to absorb twice the volume of the liquid. (Vermiculite or absorbents placed into
the bottom of the bag should be used for this purpose and may be obtained
from the Central Stockrooms.)
- Radiation Only-Contaminated Sharps
(e.g., pipettes, slides, needles, syringes, glassware, 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
are available in the Central Stockrooms.)
- Liquid infectious wastes that contain
radioactive material must be rendered biologically inactive before
the Environmental Health and Radiation Safety Department 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 the Environmental Health and Radiation
Safety Department 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 less than or equal to 0.05 uCi/ml of C-14
or H-3 or scintillation vials containing radionuclides approved for decay-in-storage
(T1/2<120days) are approved on our license for research.
- Before waste can be picked up by
the Environmental Health and Radiation Safety Department, all radioactive
waste must have the radioactive waste tag attached, labeled with the radionuclide,
date, investigator, activity and any other materials contained in the waste.
A Radioactive Waste Transfer
Form must also accompany the waste or be forwarded to the Environmental
Health and Radiation Safety Department before the waste may be picked up.
(Waste bags 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. Due to the high cost, the cost will need to be paid by the researcher generating the waste.
|| Examples of mixed waste in the laboratory setting include; organic solvents like chloroform, toluene, xylene, methanol and phenol; toxics, contaminated lead.
- Containers of stored waste should provide
adequate shielding or additional shielding must be used.
- Radioactive wastes and radioactive
materials must always be secured against theft or unauthorized access. (i.e.,
they must be kept in locked laboratories or in locked storage containers when
laboratory personnel are not present)
No research is presently approved which may
generate the following waste categories:
Radioactive animal carcasses >0.05 uCi/gm averaged over the weight of the entire animal;
Scintillation vials containing >0.05 uCi/ml of C-14 or H-3;
Scintillation vials containing radionuclides not approved for decay-in-storage.
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 less than or equal to 0.1 uCi)
However, this washwater must be recorded on an Incidental Sink Disposal Log. The form should
be posted near your designated and demarcated radioactive sink.
If activity is greater than 0.1 uCi, collect
the 1st rinsate into a liquid waste container prior to any subsequent washwater being disposed into the drain.
on Chemical Waste Disposal)
on Biohazardous Waste Disposal)