waste. Decontamination with high-pressure water has some similar
advantages, but care must be taken to ensure that used decontamination
solutions do not spread contamination.
Available treatments for solid waste include compaction and incineration. In
specific cases, there may be decontamination options available, as well.
Compaction, with pressures in the range of 40,000 to 60,000 psi, is most often used
on paper, fabric, and plastic although it is effective on glass, sheet metal, and some
other materials. With such ordinary materials, one commercial reactor has
approached up to 800 pounds of waste per 55-gallon drum, although an average of
500 pounds per drum is considered very good.
Compaction is done by drum compactor or box compactor. Compacting into a
drum or a 4- by 4- by 8-ft box is normally a labor-intensive operation and often
involves some risk of personnel exposure, even though the better compactors are
equipped with HEPA-filtered ventilation systems. Supercompaction uses
considerably higher pressures than compaction, normally 200,000 psi or greater.
Supercompaction usually involves compacting filled waste drums into a box or
overpack. Supercompaction has been success-fully used on piping and other
materials that are normally considered noncompactable.
It is really a choice of words whether incineration is considered a disposal
technique or a volume-reduction technique. All carbon, oxygen (except for any that
incinerator feed will be converted to gasses and disposed to the atmosphere.
Plutonium and most metals will remain as a solid material. As a volume-reduction
technique, incineration is very successful, with volume-reduction factors up to
200:1 or greater achieved on some waste streams. There have been licensing delays
for some incinerators, and often there are limitations brought about by air quality
restrictions. There is also the possibility that incinerator ash may be a mixed waste
due to the concentration of other impurities such as heavy metals in the waste. If a
facility has an incinerator, a quantity of the feed material can be incinerated to
determine if the waste will have hazardous characteristics before the material is
contaminated. In some cases, it is desirable to size-reduce or repackage in
combustible packaging before incineration.
Decontamination is most successful when the material can be recycled for use in a
nuclear facility since the need to prove releasability (cleanliness) is eliminated.
Nevertheless, cleaning material for unrestricted release is also possible in some
cases. It may also be possible to decontaminate an item enough to change its
classification from TRU waste to LLW, thereby allowing immediate disposal of the
item, while a relatively small quantity of decontamination waste is stored as TRU