ExxonMobil Corporation (State of Texas)
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:||Unknown|
|Location:||Three Rivers, TX|
2.0 Site Status Summary
The Ray Point Mill Site was originally developed and operated as a mill for surrounding conventional surface mines. The site consisted of a mill complex with an approximately 50 acre tailings impoundment. A radioactive material license authorizing processing of uranium ore was issued to Susquehana-Western, Inc. in March of 1970. Exxon Company, U.S.A. acquired the site from Susquehana-Western in September of 1973. Subsequently, the name of the entity to which the license is issued changed numerous times over the years, but always with it being some entity with the name Exxon. In 1986 the license was amended to specify its issuance to Exxon Corporation, and is currently issued in the name of ExxonMobil Corporation.
At the time of the license transfer to Exxon in September of 1973 the authorization on the license was changed from "processing of uranium ore to uranium concentrate" to "storage only" and a condition added specifying the plan for stabilization of the tailings. Exxon decommissioned the facility, including dismantling of the mill site structures, and completed closing the tailings impoundment. The tailings impoundment has been capped and a vegetative cover established for approximately 20 years.
The licensee has performed radon flux testing on the capped impoundment to demonstrate compliance with the 20 pCi/m2-sec requirement. Subsequently, contaminated soil was discovered at the site that was missed during decommissioning. The licensee applied for and was approved to dispose of the contaminated soils by opening a trench in the side wall of the impoundment.
Later, additional contamination was found at the site and on adjacent properties. The volume of the contaminated material was such that placement in another trench was not considered to be prudent. The licensee applied and was approved to construct a disposal cell adjacent to the tailings impoundment for placement of the additional contaminated material. Both the tailings impoundment and the adjacent disposal cell are being monitored for performance.
Since all structures and equipment have been removed from the site, there will be no release of equipment and materials to unrestricted use. The criteria for release of the site/termination of the license includes demonstration that the tailings impoundment does not exceed the radon flux limit of 20 pCi/m2-sec; gamma levels are indistinguishable from background; radium-226 concentration in soil does not exceed 5 and 15 pCi/g of radium-226 in the first 15 centimeters, and subsequent 15 centimeter soil horizons, respectively; natural uranium in soil does not exceed 30 pCi/g; demonstration that the tailings impoundment and disposal cell have stabilized; and either demonstration that the groundwater does not exceed the limits specified in a table that is comparable to Paragraph 5C in 10 CFR 40, Appendix A, or does not exceed alternate concentration limits, if so established.
3.0 Major Technical or Regulatory Issues
ExxonMobil has gained full access to adjacent property through purchase and has assessed the off-site surface contamination and determined that there are no groundwater impacts. ExxonMobil will need to submit an application for amendment of the license to dispose of surface contamination removed from the adjacent property.