Applications are made for the medical, space, aviation and petroleum exploration sectors. Products are for example shields against radioactive sources and balance weights for aeroplanes. However, most DU is used in the military industry: in munitions and armour plates. For workers and people in the neighbourhood it is a very unhealthy industry.

Process

The process to make uranium products from derbies involves several steps.

Casting

Derbies are melted in melting furnaces. DU is hardened, and alloyed for example with 0.75% titanium or 2% molybdenum, if desired. Depleted uranium is cast into finished products or the metal is poured into ingot moulds for further processing. The ingots oxidise. The silver white metal first turns tea brown and then black after a few days.

Rolling and heat treatment

Ingot castings are preheated in a salt bath (650C) prior to rolling. Rolling occurs to produce sheet. Rolled sheet may be sheared, sawed and reheated. The rolling schedule and heat treatment are dependent upon the texture, grain size and mechanical properties desired.

Fabrication

Depleted uranium plate and sheet are precision sheared, punched and machined to final dimension. Machines may be ventilated and enclosed to protect workers from inhaling and ingesting DU particles. Uranium products may be coated or clad to protect the surfaces, reduce exposure to personnel or to comply with regulations. Various coating materials such as acrylic paint, zinc, and nickel may be applied.

Load, assemble and pack

The sub-components are united to produce the complete product. The various parts of munitions are loaded, assembled and packed.

Waste

Repeatedly, industries involved in depleted uranium violate (environmental) laws and regulations in their radioactive and toxic 'waste management'. Only a few of these violations are: leaking drums, drums in such poor condition that they break apart when moved, stored drums with the contents not labeled, repair of steel ducts with tape and overflowing evaporation ponds.

Airborne particles

For workers producing uranium munitions and for neighbours of these facilities it is inevitable to inhale fine uranium particles or dust. National Lead Inc. in Albany, US, reduced depleted uranium tetrafluoride and processed metal into munitions. The facility was shut down by New York state in 1984. The airborne radioactive release exceeded the standards by far. Uranium particles were found up to 26 miles (16 kilometres) downwind of the facility. Also DU was found in soil at levels 500 times higher than surrounding communities. The total cleanup cost of the site is estimated, in 2004, to be US$165 million.

Solid waste

Uranium is pyrophoric, when divided in fine particles. Pyrophoric substances oxidise rapidly, 'burn' in air. Grinding sludge, machine turnings, DU shavings, scrap and other fine particles of DU have to be kept under water, under mineral oil, in sand or in concrete to prevent a pyrophoric reaction. This fine metal waste may be made compact, melted and recycled. DU packed in oil can not be recycled this way. It can also not be stored, because the drums start releasing hydrogen after some years. Facilities in France, used to burn this waste in open air.