Allied Chemical Corporation

Site Description

“On February 4, 1957, the Allied Chemical and Dye Corp. announced selection of Metropolis Ill., as the site of its plant to process 5,000 tons of U3O8 a year under contract with the [Atomic Energy] Commission” (AEC 1957). The official plant startup date appears to be January 1, 1959, but there are indications that uranium and uranium workers might have been on the site in late 1958. One individual reported participating in opening ceremonies at Allied Chemical’s fluorine plant at Metropolis, Illinois in October 1958 (Sloop 1978), which indicates that uranium exposure could have occurred as early as October 1958.

Allied Chemical operated its UF6 production facility using a dry conversion process (versus a wet solvent extraction process) to supply UF6 feed for the Paducah Gaseous Diffusion Plant through June 30, 1964, under an AEC contract (Perkins 1982). In addition, Allied Chemical was sampling uranium concentrates for other entities as of 1982.

On June 30, 1964, the plant was temporarily closed. AEC (1966) reported that the plant “may be
reopened in 1966 for uranium hexafluoride production.” Perkins (1982) noted that ACCP resumed
operations in February 1968, but the available dosimetry records indicate that radiological exposures were still occurring at the plant between June 30, 1964, and February 1, 1968. Some of the claimant interviews and external dosimetry records show that a number of workers were on the site during the shutdown, and hiring was occurring in 1967, although these records also indicate that a number of workers were laid off in July 1964. The available records do not indicate what activities might have been ongoing in the plant during the shutdown period. However, based on U.S. Department of Labor job descriptions associated with one claim (Claim Number redacted), some processing operations might have continued at least on a sporadic basis.

The ACCP U.S. Nuclear Regulatory Commission (NRC) license (NRC 2003, p. 8-2) states:
The Allied Signal Metropolis Plant is located on approximately 1,000 acres of land in Massac County at the southern tip of Illinois, along the north bank of the Ohio River. The site perimeter is formed by US Highway 45 to the north, the Ohio River to the south, an industrial coal blending plant to the west and privately owned, developed land to the east. Plant operations are conducted in a single fenced-in, restricted area covering 59 acres in the north-central portion of the site.

The plant is now owned by Honeywell and is still providing UF6 to gaseous diffusion plants for use in the commercial sector.

The following description of the buildings is excerpted from ACCP licensing documentation (NRC
2003, pp. 8-8 to 8-9). The list was originally numbered 8.5.1 through 8.5.8, but has been simplified to 1 through 8 below.
Most of the uranium processing equipment is housed in a six-story structure termed the Feed Materials Building where essentially all of the steps in the UF6 manufacturing process are conducted. Other areas and buildings in which operations are conducted involving the handling or processing of significant quantities of source material include the following:

1. A Sampling Plant which receives samples or concentrates for uranium assay
and moisture content.

2. The Sodium Removal (pretreatment) and Uranium Recovery Facilities which are housed in buildings where high sodium content ore concentrates are treated to remove sodium impurity, and where materials are reprocessed to recover additional uranium.

3. The KOH [potassium hydroxide] muds washing facility which removes fluorides and KOH from the potassium diuranate muds generated in the fluorination scrubber system. The washed potassium diuranate is then processed through Sodium Removal. The wash liquors are neutralized at EPF [environmental protection facility, this facility probably did not exist during the early years].

4. The Calcining Facility which dries the incoming feed material and recovered uranium as the first step in ore preparation.

5. The Pond Mud Calciner Drier where hard/wet ore concentrates and KOH Muds are processed prior to packaging for blending with additional ore concentrates at the Feed Materials Building for conversion to UF6.

6. The Laboratory Building which houses facilities for conducting process control, product, and radiological control analyses.

7. The Cylinder Wash Building where UF6 product cylinders are periodically washed and hydrostatically tested prior to reuse.

8. Outdoor pads for storage of drums of ore concentrates and other uranium bearing materials, as well as UF6 product cylinders. Additional plant facilities which are involved directly in the UF6 manufacturing process but do not involve the handling of any significant quantities of source material include a fluorine manufacturing building, a fluoride waste treatment facility with four large CaF2 settling tanks, a powerhouse, a reductor off-gas incinerator, and two small uranium settling ponds to collect any uranium spills.

Allied Chemical was also involved in the manufacture of 30,000 pounds per week of liquid fluorine, 1,200 tons per year of sulfur hexafluoride, 2,500 pounds per week of antimony pentafluoride, and 10,000 pounds per week of iodine pentafluoride (Perkins 1982). These materials were not radioactive.