Aerial photograph of the Advanced Mixed Waste Treatment Project showing

1: Waste Storage Facilities; 2: Treatment Facility; and 3: Characterization Facility.

The vast majority of the waste processed at the AMWTP resulted from the manufacture of nuclear weapons components at Colorado's Rocky Flats Plant. Shipped to Idaho in the '70s and early '80s, the waste contains industrial debris, such as rags, work clothing, machine parts, and tools, as well as soil and sludge, and is contaminated with transuranic radioactive elements (primarily plutonium). Most of the waste is "mixed waste" contaminated with non-radioactive hazardous chemicals such as oil and solvents.

At the AMWTP, each container of waste is prepared and examined prior to approval for shipping to WIPP. BNFL must verify records about the waste's generation and contents and decide how to treat each container, based upon what it finds during waste characterization.

After the waste containers have been retrieved from the storage facilities, they are examined in the AMWTP Characterization Facility. During characterization, each container is examined and tested to determine its contents. The characterization facility houses real-time radiography units, a headspace gas sampling glove box, a drum coring unit, and gamma spectrometry equipment. The containers are first x-rayed in real-time radiography units, which are powerful enough to see the components of a light bulb inside a drum. Next, the container is tested using gamma spectrometry, which measures the radiation present. Drum coring is used to take a sample of the contents of certain drums.

Some of the containers are also tested using headspace gas sampling, which checks the container for any harmful gases. This is done inside a glove box. After the containers have been characterized, they are either sent to the loading facilities for packaging and shipment or to the Treatment Facility for further processing.

Waste may be repackaged, sized (cut into smaller pieces), supercompacted (squashed to reduce waste volume) or stabilized by adding material to absorb liquids. Approximately 70 percent of the waste is sent to the Treatment Facility's supercompactor, which can compact a 55-gallon drum to roughly one-fifth its original size. This treatment reduces both the number of shipments required and the disposal space required at WIPP. A shredder reduces wooden boxes and metal drums to sawdust and metal scrapings.

The facility also has two waste treatment box lines, which contain manipulators for remote handling of the radioactive waste. In the box lines, the waste is sorted and size-reduced, if necessary. Any restricted items, such as liquids or compressed gas cylinders, are removed, and the waste is repackaged. Waste is transported to different areas in the treatment facility by an intricate system of conveyers, and all waste handling is done remotely.

Loading the TRUPACT II containers for shipment to the WIPP in New Mexico is a vital part of the waste preparation process. After characterizing the waste containers in the Characterization Facility, they are either sent to the Treatment Facility for processing or directly to one of the loading facilities.

There are two AMWTP loading areas. In both of the loading areas, the waste containers go through two major steps: payload assembly and TRUPACT II loading. Payload assembly includes categorizing the waste into four different groups consisting of 55-gallon drums or pucks, which are compacted drums. These four separate payloads are then individually loaded into the TRUPACT II containers for shipping. A TRUPACT II container is a special, double-containment vessel that is approved for waste transport. After the payloads are placed in the TRUPACT II containers, the containers are put through various visual and mechanical inspections before they are certified for travel.

Under the terms of its operating permit with DEQ, the AMWTP is regularly inspected to ensure that it is meeting all of the regulations pertaining to radioactive and hazardous waste.

The Nuclear Regulatory Commission must be satisfied with the facility's shipping plans, as must each state along the shipping corridor: Idaho, Wyoming, Utah, Colorado, and New Mexico. Representatives from the Department of Energy's Idaho Operations Office, DEQ, and the Idaho State Police also scrutinize the facility, the processes that are used to prepare waste for shipment, and its quality control, safety assurance, and emergency response procedures.