Weston Solutions, Inc.

This site description was provided by the cognizant Agreement State, and the U.S. Nuclear Regulatory Commission (NRC) makes no claim regarding the validity of the information provided. See our Site Disclaimer for more information.

1.0 Site Identification

Type of Site: Complex Decommissioning Site
Location: West Chicago, IL
License No.: STA-583
Docket No.:
License Status: Unknown

2.0 Site Status Summary

The Kerr-McGee Rare Earths Facility (REF) is located on a 43-acre parcel of land within the city limits of West Chicago. The REF is surrounded by light commercial, shopping areas, and residential housing. A rail line separates the housing on the west side from the facility. The REF was originally operated by Lindsay Chemical Company, subsequently by American Potash and Chemical Company, and finally by Kerr-McGee Chemical Corporation, which created Tronox, LLC (Tronox) as a subsidiary company. Tronox filed for bankruptcy in January 2009 and Weston Solutions, Inc. (Weston), as trustee for the West Chicago Environmental Response Trust (WCERT), is the current Radioactive Material Licensee (see Section 4.0 below). The facility operated from 1932 through 1973, producing and refining chemicals and metals, including thorium and rare earth compounds from ores. Kerr-McGee operated the facility for a short period between 1967 and 1973 under license from the U.S. Nuclear Regulatory Commission (NRC), previously the Atomic Energy Commission. Many of the early operations were conducted prior to the regulatory scheme established by the Atomic Energy Act in 1954.

From 1932 to 1973, thorium was produced at the facility both for commercial purposes and for the federal government. Commercially, thorium was primarily used in gas lantern mantles, such as those formerly used for "gaslights" for street and home lighting and now used on a more limited scale in camping lanterns. The federal government purchased thorium for national stockpiles established by the Strategic and Critical Materials Stockpiling Act of 1946. Beginning in 1953, the General Services Administration procured some of the product from the West Chicago facility, and during the late 1950's, the Atomic Energy Commission purchased thorium processed at the site.

In September 1993, Kerr-McGee submitted a license application to decommission the facility. After an extensive review period, in February 1994, the Illinois Emergency Management Agency (IEMA) informed Kerr-McGee that a phased approach to site decommissioning would be acceptable. IEMA has authorized a total of eight phases, and prepared environmental impact assessments for each phase. The major activities authorized and accomplished under these phases are detailed below. In some cases, work authorized under one phase was not completed until a subsequent phase.

Phase I (May 1994): site preparation, including construction of support zone facilities, a retention pond, a rail siding, and a railcar loading facility.

Phase IA (August 1994): construction of additional support zone structures.

Phase IB (September 1994): shipment of significant amounts of material from surface stockpiles (sediment, tailings, debris piles, and containerized materials) to Envirocare; management and shipment of contaminated off-site materials brought on-site for shipment to Envirocare via the railcar loading facility.

Phase II (April 1995): excavation of waste pond sediments and some below-grade material; construction of infrastructure facilities; preparation of the site for a Water Pre-Treatment Plant and a Physical Separation Facility; backfilling of certain areas subject to IEMA verification.

Phase IIA (September 1995): shipment of 87,000 tons of contaminated on-site material and 54,000 tons of contaminated off-site material to Envirocare for disposal during calendar years 1995 and 1996.

Phase III (February 1997): excavation of contaminated materials; installation of sheet piling; backfilling of excavations and grading; construction of haul roads; construction and operation of the Water Treatment Plant and Simplified Physical Separation Facility; delineation drilling; groundwater monitoring. During 1997, 27,000 tons of contaminated material from the site and 51,000 tons of off-site material were shipped for disposal.

Phase IV (April 1998): deep excavation below the water table; dewatering; backfilling and final grading of the site. The site cleanup, except for groundwater remediation and a small footprint of contaminated soils beneath the railcar load-out facility was completed in November 2004. The railcar facility continued to operate while off-site materials were being received from the U.S. Environmental Protection Agency (USEPA) Superfund cleanup of Kress Creek and the residential areas.

Phase V (June 2013): groundwater remediation is the final phase of cleanup under closure requirements outlined in the licensing regulations for this source/mill tailings site. A groundwater corrective action plan (CAP) was submitted by Tronox, and accepted by IEMA. Implementation of corrective actions could take 5 to 50 years to achieve the groundwater protection standards established to meet unrestricted release of the site.

In 2013, the WCERT hired contractors to excavate and ship contaminated materials, and restore the REF site to the final grading plan established in 1996. This contract was awarded in May 2013 and excavation activities started in July 2013. Work was scheduled to be completed in November 2013 but more subsurface contamination than estimated was discovered pushing the project into 2014.

Decommissioning activities in 2014 showed some progress with characterizing, excavating, and shipping contaminated soils that were previously unaccounted for. However, funding limitations (see Section 4) delayed the project from timely removal of the remaining source term until the spring of 2015. By the spring of 2015, Title X Department of Energy reimbursements had been re-established and the decommissioning was able to be completed. With the final railcar of contaminated soil shipped to Energy Solutions in Clive, Utah in November of 2015.After the soil remediation portion of the project was completed, the primary project focus has been on groundwater remediation.

Specific standards for residual radium and uranium in on-site soils must be remediated to a maximum total radium concentration of 5 picoCuries per gram (5 pCi/g) above background as specified in 32 IAC 340 Appendix A.  The standard for total residual uranium is 20 pCi/g which is based on analyses of potential health risks resulting from unrestricted use of the site. Free release of structure and equipment must also meet 32 IAC 340 Appendix A values.

3.0 Major Technical or Regulatory Issues

In the absence of soil contamination, groundwater contamination will be the focus of remediation moving forward. Groundwater beneath and down gradient of the West Chicago facility has been impacted by the presence of the facility. Elevated concentrations of several inorganic constituents and radionuclides derived from facility wastes are present in the glacial aquifer. IEMA has established groundwater protection standards for 20 constituents of concern (mainly non-radioactive) at the West Chicago facility. These criteria are consistent with applicable standards established by the NRC, USEPA and the Illinois Environmental Protection Agency and have been incorporated into Weston's radioactive material license.

IEMA regulations required that Kerr-McGee/Tronox develop and implement a corrective action program to address contaminated groundwater. In December 1997, Kerr-McGee/Tronox submitted a conceptual CAP in which source removal, natural attenuation, and groundwater treatment are the major remedial actions. Weston has recently submitted a revised CAP to include additional information requested by IEMA. It is anticipated that to achieve compliance with all 20 groundwater protection standards, natural attenuation processes will have to continue for many years after the site contaminated source term has been removed. Alternative groundwater remediation options such as pump and treat and grout in place are being evaluated. The West Chicago license will not be terminated until full compliance is demonstrated.

Currently, the WCERT is conducting a series of in situ and ex situ investigations in order to determine a groundwater remedy. These investigations will focus primarily on areas inside of the sheet piling systems installed as result of deep excavation activities during the soil remediation phase and will help refine the groundwater corrective action plan. Although not the official remedy of record, the preliminary investigations suggest the most viable remedy will be an in situ leachate process for the removal of uranium. Once a remedy is developed and in place, it is anticipated to take 5-10 years to meet the groundwater protection standards stipulated by the license. Areas outside of the sheet pile systems are expected to meet the uranium groundwater protection standards via natural attenuation.

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Page Last Reviewed/Updated Tuesday, March 09, 2021