the process to plate or precipitate the material as a final step in the process line,
before it is declared a waste.
Most plutonium facilities will produce TRU waste or TRU mixed waste.
According to national policy, DOE TRU waste is supposed to be permanently
disposed of at the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico.
Volume allocations have been given to each DOE site for the waste to be placed
there, so limiting the quantity of high-level TRU waste is extremely important.
Therefore, volume reduction of TRU waste is highly desirable. Incineration offers
the greatest volume reduction and has the added advantage of destroying some
types of hazardous constituents (flammable and other organic compounds).
High-level wastes are slated to be disposed of at a high-level waste repository. A
site at Yucca Mountain, Nevada, is being evaluated for this purpose. In the interim,
TRU waste is being stored either at the sites that are generating it or, for some DOE
facilities, at the Nevada Test Site, until a final repository is available. Long-term
maintenance of interim storage facilities, plus the prospect of later moves to the
final disposal site and burial at that site, make high-level waste very costly.
The only airborne plutonium likely to arise from either normal operations or
decommissioning of DOE facilities will be in a particulate form. Although plutonium
vapors are possible during cutting and perhaps some grinding operations, they will soon
condense to particulate material.
Plutonium particulates are notoriously difficult to confine and extensive use is
made of glove boxes, local ventilation systems, fixatives, and other means to
minimize generation of particulates and to confine them. The high-efficiency
particulate air (HEPA) filter is the backbone of plutonium air-cleaning systems.
Such filters are certified to have a 99.93% removal efficiency for particulates of 0.3
Ám and larger and are normally used with at least two in series.