United States Nuclear Regulatory Commission - Protecting People and the Environment

Cimarron (Kerr-McGee)

1.0 Site Identification

Type of Site: Complex Decommissioning Site
Location: Oklahoma City, OK
License No.: SNM-928
Docket No.: 70-0925
License Status: Active License
Project Manager: Ken Kalman

2.0 Site Status Summary

The Cimarron site is located close to Cimarron City, Oklahoma. The 340-ha [840-ac] site is along the southern bank of the Cimarron River about 1 km [0.5 mi] north of the Oklahoma State Highways #33 and #74 intersection and 40 km [25 mi] north of Oklahoma City, Oklahoma. The area is primarily rural with rolling hills and incised drainages. Vegetation in the area consists of native grasses and various stands of trees along and near drainages. The Cimarron site was used to fabricate enriched uranium and mixed oxide fuels for nuclear reactors from 1965–1975. On site, there were several buildings, collection ponds, sanitary lagoons, storage areas, and burial areas. Originally, the complex was owned and operated by Kerr-McGee Corporation (KMC). Later, Cimarron Corporation, a wholly-owned subsidiary of KMC, became responsible for the site. In 2005, ownership of Cimarron Corporation was transferred to Tronox Incorporated, who filed for bankruptcy in 2009. In 2011, Cimarron Environmental Response Trust assumed responsibilities for the Cimarron site, including completion of the decommissioning activities.

The Atomic Energy Commission (AEC) issued Radioactive Materials License SNM-928 in 1965 to KMC for the uranium fuel fabrication facilities at the Cimarron site. Later, AEC issued Radioactive Materials License SNM-1174 in 1970 to KMC for the mixed oxide fuel fabrication (MOFF) facilities at the Cimarron site. Production of nuclear fuels continued until 1975 when all production operations ceased. Less than 20 percent of the 340-ha [840-ac] site were impacted by the nuclear activities.

Decommissioning efforts were initiated in 1976. Characterization activities and decommissioning were first conducted for the MOFF building and associated areas, which included evaporation ponds, emergency ponds, sanitary lagoons, underground tanks, a septic tank, and a fenced area around the MOFF building. In 1990, Cimarron Corporation submitted a final survey of the MOFF building and associated areas to the U.S. Nuclear Regulatory Commission (NRC), which is the successor of the AEC, and requested termination of the Radioactive Materials License SNW-1174. NRC had a final confirmatory survey conducted and, based on the results, terminated the MOFF License, SNW-1174, consistent with regulations at the time in 1993. However, the land and the exterior of the MOFF building were not released for unrestricted use because they were within the bounds of the uranium fuel fabrication license, Radioactive Materials License SNM-928.

In the following years, characterization activities continued and decommissioning plans were developed and approved by NRC for the facilities associated with the Radioactive Materials License SNM-928. The site was divided into three areas that included affected and unaffected areas. The areas were further subdivided into subareas. Cimarron Corporation submitted a Final Status Survey Report (FSSR) for each subarea when the decommissioning activities were complete for each subarea. Following NRC review and acceptance, the subareas were released for unrestricted use and removed from Radioactive Materials License SNW-928. By early 2000s, the majority of the site has been released by NRC for unrestricted use.

Monitored Natural Attenuation was used to remediate uranium in the groundwater at the site. However, unrestricted release standards were not achieved. Uranium concentrations in groundwater were in excess of release criteria for the Burial Area #1, Western Alluvial Area, and the Western Upland Area. Plans were developed to lower the uranium concentration through groundwater remediation and bioremediation was proposed as an alternative in 2008. The NRC staff had concerns about the use of bioremediation at the site and progress resolving these concerns was delayed because Tronox Incorporated filed for bankruptcy in 2009. After Cimarron Environmental Response Trust became the trustee and licensee for Radioactive Materials License SNW-928 in 2011, discussions with NRC were conducted to evaluate alternative remediation methodologies.

By mid-2014, the trustee had determined that pump and treat was the best option for groundwater remediation.  In June 2015, NRC staff will met with the trustee and the Oklahoma Department of Environmental Quality (ODEQ) to discuss the trustee's conceptual model for groundwater remediation.  The trustee submitted its license amendment request to approve a rmediation plan was submitted in December 2015. NRC staff reviewed the submittal and transmitted requests for additional information. In response to this request, the trustee conducted additional studies related to groundwater remediation and will be submitting a revised remediation plan in August 2018.

3.0 Major Technical or Regulatory Issues

By letter dated January 12, 2009, Cimarron's parent company, Tronox, informed the NRC that it filed for bankruptcy under Chapter 11 in Federal Bankruptcy Court. The NRC staff responded by letter dated February 11, 2008 to acknowledge the bankruptcy and inform the licensee of its obligations to comply with NRC regulations regardless of the bankruptcy. On February 14, 2011, the Cimarron Environmental Response Trust became the trustee and licensee for the Cimarron site.

Since then, funds recovered from the Tronox bankruptcy and the Anadarko Settlement totalling more than 85 million dollars have been added to the Trust to be used for decommissioning activities.

One significant regulatory issue that was resolved was whether NRC will allow Cimarron to remediate the groundwater under SDMP criteria or if Cimarron's choice of remediation technique will require the use of criteria from the License Termination Rule. OGC reviewed the issue and by letter dated November 10, 2005 stated that Cimarron's preferred technologies of "pump and treat" or excavation could be performed under SDMP criteria. However, subsequent technical staff and OGC interpretation will allow for the use of other technologies under SDMP criteria provided that there is no change in the criteria for remediation.

4.0 Estimated Date For Closure


Page Last Reviewed/Updated Monday, August 06, 2018