preferable to sand blasting in which the sand would be added to form an additional
mixed waste that could require storage for many years.
Laundry wastes are a special problem because radioactive contamination, body
oils, and odors must be removed from protective clothing. For a time, dry cleaning
was extremely popular, because the solvents were easily redistilled and recycled.
However, because the solvents were usually chloroflorocarbons and because the
small volume of waste generated was mixed waste, this method is now rarely used.
Incineration of disposable protective clothing is an outstanding choice if an
incinerator of sufficient capacity is available, but this is rarely the case. Water
washing is often the method of choice. In a few cases, plutonium in the waste
stream is removed adequately by filtration and the effluent can be disposed to a
sanitary sewer or to the environment under a National Pollutant Discharge
Elimination System (NPDES) permit. It is important to select a detergent for water
washing that does not foul or plug the filter and that has a minimal impact on ion
exchange resins if they must be used. Many household laundry detergents have
fillers such as wood fiber to give them greater bulk. These should never be used
because the fiber has no beneficial use and will end up as solid waste. As a general
rule, extensive testing on clean material should be done to optimize disposal of
Floor-drain wastes are much more of a problem in some facilities than in others. In
some facilities, there is a culture that says, "if you don't know what to do with it,
pour it down the floor drain." Such practices can lead to a mixture of water,
detergent, oil, antifreeze, and other substances that clog filters and foul ion
exchange resins. In the worst cases, solidification with Portland cement is the only
alternative, and this increases an already large volume. The use of catch basins
under chemical and lubricating systems and extensive training of personnel
minimize the probability of such occurrences. Oil skimmers on floor drain
collection tanks are sometimes advisable, as well.
Once the facility is properly designed, training of personnel is the primary
operational control against generating excessive volumes of waste or against
generating waste with contaminants that interfere with treatment or change the
Some facilities have used color codes to prevent materials from entering an area
where they will adversely affect waste management. For example, certain
electronic contact cleaners may be banned from some radiologically contaminated
plant areas because they would generate mixed waste. The procurement
organization might code all such materials red and certain areas would be posted to
indicate that the materials were not allowed.