AAR Manufacturing, Inc.
1.0 Site Identification
|Type of Site:||Complex Decommissioning Site|
|License Status:||Terminated License|
|Project Manager:||Ted Smith|
2.0 Site Status Summary
I.A. Allen Industrial Sales, founded in 1951 and incorporated in 1955, was renamed AAR Corporation in 1969. AAR Corporation provides aftermarket support to the aviation/aerospace industry. AAR Manufacturing Inc. (AAR) is the industrial arm of AAR Corporation. In 1981, AAR purchased the Brooks and Perkins, Corporation (B&P) in Livonia, Michigan. B&P was licensed by the U. S. Atomic Energy Commission (AEC) to possess and use 6,804 kg [15,000 pounds] of thorium in thorium master and magnesium alloys. B&P operated from1957-1971 manufacturing products from thorium alloy.
The 45,000 m² [484,400 ft²] site is located in Livonia, Michigan approximately 32.2 km [20 miles] northwest of downtown Detroit, Michigan (Figure 1). Initially, the site consisted only of an old commercial building and a mill. By 1970, an addition to the commercial building was built on the northeastern part of the property. Before the property was purchased by AAR, another addition was connected to the mill over existing contaminated soil (the soil was remediated later, in 2000). The current AAR site is divided into an eastern and a western parcel. Now, the AAR site contains a small, 140 m² [1500 ft²] out building, a gravel parking area, and a 16,000 m² [172,000 ft²] facility previously used for offices and manufacturing.. To the north are light commercial developments, to the east is Inkster Road, to the south are Chessie System Railroad tracks, and to the west is a commercial trucking facility.
B&P received its Source Material License No. D-547 from the AEC in January 1957. This license was replaced by License No. STB-362 in August 1961. B&P was authorized to possess thorium metal pellets and magnesium-thorium alloy. These materials were sold in wrought form or as fabricated parts. The master alloy was heated, melted, and poured into molds. After cooling, the castings were removed, cut, and trimmed. The metal scrap was recovered, heated and melted, rolled into sheets, and then pickled in an acid bath. The final product was sanded, ground, and brushed prior to shipping.
Site soils became contaminated with thorium due to manufacturing processes and practices over the years. Contamination was concentrated in the western parcel and in discrete locations on the south boundary to the east. The soils were contaminated from the surface down to a depth of two meters at some locations. A radiological survey was undertaken by B&P in 1970 to support license termination. B&P removed and disposed of thorium-bearing wastes in 1971 and their license was terminated by the AEC in May 1971. In 1981, AAR acquired the assets of B&P to help start its manufacturing group.
The Oak Ridge National Laboratory (ORNL) had a project to review sites with terminated licenses and investigated the old B&P (now AAR) site in 1994. ORNL reported its findings to the U.S. Nuclear Regulatory Commission (NRC). The NRC Region III later inspected buildings and soils for contamination and found thorium concentrations above NRC release criteria in effect at the time. The AAR site was added to the Site Decommissioning Management Plan list in August 1994. Because AAR is the current owner, it is responsible for the cleanup of any residual contamination at the site.
In 1996, AAR began negotiations with the NRC to remediate the site. B. Koh and Associates, Inc. carried out site characterization surveys in 1995, 1998, and 2000. Dose assessments were submitted by AAR to the NRC in 2000 and 2002 based on the site characterizations. In 2002, AAR proposed a decommissioning option for restricted use of the western parcel and unrestricted use of the eastern parcel. The restrictions only allow industrial use of the site and prohibit farming and residential use, which would transfer to any subsequent owners of the property through the deed.
In 2003, Oak Ridge Institute for Science and Education sampled portions of the AAR site soil contamination at the request of the NRC. In 2004, NRC specified areas of the site recommended for remediation. In 2005, on behalf of AAR, Partners Environmental submitted a revised probabilistic dose analysis and proposed remedial action plan based on NRC’s evaluation. The submittal was revised by AAR in August 2006 and accepted by the NRC in October 2006. AAR would remove and dispose of thorium contaminated soil to a depth of 1 meter from four 100 m² [1076 ft²] grids in the western parcel and two 100 m² [1076 ft²] grids in the eastern parcel. In November 2006, AAR submitted a plan addressing remediation of the site and in 2007 NRC inspected and documented the final remedial activities. The excavations from the grids were filled with clean soil from Waterford Township in Michigan, and the contaminated soil was sent to an authorized disposal site. After completion of the planned remediation, the site meets site dose limits for both unrestricted release for the eastern parcel and restricted release for the western parcel. In December 2009, a meeting was held between AAR and the NRC to determine the future steps needed to finish the decommissioning process and close-out the site. Discussions are ongoing with AAR to consider options for additional remediation of the western parcel sufficient to achieve unrestricted release.
3.0 Major Technical or Regulatory Issues
AAR is not a licensee.
4.0 Estimated Date For Closure