Airbone Waste

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

type of waste they can accept. If possible, it is generally better to treat the waste than to

destroy or chemically alter the hazardous component. In some cases, mixed waste may be

treated to encapsulate the hazardous component so that it no longer has the leachability or

other characteristics that cause it to exhibit hazardous properties. Mixed waste requires

special permits for treatment, so it is generally preferable to avoid generating it or to treat it

in connection with some other process while it is a useful material (before it becomes a

waste). For example, if the hazardous component is a metal with some recycle value, or it

there are recycle metals in the material, it may be best to alter 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.

8.2

AIRBORNE WASTE

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.

8.2.1 Design Objectives

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 :m and larger and are normally used with at least

two in series.

8-5