Tronox, LLC — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration JAN 1 5 2008 1200 New Jersey Avenue, SE Washington, D.C. 20590 Mr. Mark Krippel Tronox, LLC 800 Weyrauch St., West Chicago, IL 60 185 Ref. No. 07-0205 Dear Mr. Krippel, This responds to your October 1 1,2007 email requesting clarification of the applicability of hazardous substance requirements to the transportation of non-hazardous materials containing radionuclides under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-1 80). Specifically, you ask whether the HMR apply to the bulk transport of non- hazardous material containing naturally-occurring radionuclides that exceed the reportable quantity (RQ) threshold. You indicate in your example that soil from a remediation site containing 10 pCi/g of thorium-232 is transported in a 103-ton capacity rail car and is subject to the HMR as a Class 9 hazardous substance because the total quantity in curies (Ci) in the rail car exceeds the RQ for thorium-232 (0.00 1 Ci). Your understanding is correct. By definition, your example would qualify as a hazardous substance and be subject to the HMR. A hazardous substance (as defined in 5 171.8) means a material, including its mixtures and solutions, that is listed in Appendix A to 5 172.101 of the HMR; is in a quantity, in one package, that equals or exceeds the reportable quantity (RQ) listed in Appendix A to 5 172.101 of the HMR; and for radionuclides, when in a mixture or solution, conforms to paragraph 7 of Appendix A to 5 172.10 1. The Superfund Amendments of 1986 require PHMSA to list and regulate as hazardous materials those hazardous substances listed or designated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980. The intent of the requirement is to enable transporters of hazardous materials to identify CERCLA hazardous substances and to make the required notification if a release occurs. Additionally, based on guidance from the EPA Office of Solid Waste and Emergency Response, a release#

Page 2of naturally-occurring radionuclides from the transportation of soil removed from a remediation site is subject to reporting under 40 CFR 302.6(c). Please consult 40 CFR 302.6(c) for categories of releases that are exempt from the EPA notification requirements. I hope this information is helpful. Please contact us if you require additional assistance. / chief, Standards Development Office of Hazardous Materials Standards#

Page 3, Drakeford, Carolyn <PHMSA> From: Sent: To: Subject: INFOCNTR <PHMSA> Thursday, October 11,2007 3:02 PM Drakeford, Carolyn <PHMSA> FW: Information Center CommentslQuestions % AH 07 -0205 . - Carolyn, Could you process this as a formal request for interpretation? Thanks buddy! Erin ----- Original Message----- From: mark.krippel@tronox.com [mailto:mark.krippel@tronox.com] Sent: Thursday, October 11, 2007 12:59 PM To: INFOCNTR <PHMSA> Subject: Information Center Comments/Questions Below is the result of your feedback form. It was submitted by Mark Krippel (mark.krippel@tronox.com) on Thursday, October 11, 2007 at 12:59:24. Name: Mark Krippel Category: Hazardous Materials Table, Special Provisions, Hazardous Materials Communications Organization: Tronox LLC Street: 800 Weyrauch St City: West Chicago State: Illinois Zip Code: 60185 Phone: 630-293-6331 Comments: I am in need of a technical contact to discuss the applicability of radionuclide RQ shipping requirements for near background concentrations of natural thorium. Specifically, bulk shipments by rail or barge of materials below the 27 pCi/g thorium threshold for a radioactive materials shipment, but because of the bulk volume of the conveyance requires shipment as a Class 9 RQ hazardous material. The extreme example is a bulk barge shipment where, many commodities like coal and depending on capacity, even limestone, would seem to require shipment as a Class 9 RQ hazardous materials shipment because of the thorium content typically found in these materials. In my particular case, we are being required based on a reading of DOT regulations, to ship 10 pCi/g (Th-232) soil from a remediation site as a Class 9 RQ hazardous material because the 103 ton capacity railcar results in a total curie content greater than the 0.001 Ci RQ for Th-232. A barge quantity of background concentration coal or limestone could also exceed this threshold. It does not seem this situation is one that the law was intended to regulate. As a side note, I found in my review of the 1989 background technical document for the RQ 1#

Page 4rulemaking, that EPA used what is now outdated radiation dosimetry guidance to derive the RQ for thorium and that use of the currently accepted E P A / I C R P radiation dosimetry * guidance would raise the RQ to 0.01 Ci or higher and eliminate this issue entirely. Getting EPA to initiate new rulemaking would likely take years. I am hoping that a DOT regulatory interpretation may exist that would allow these low concentration materials to be shipped as non-hazardous. Thank you for your assistance, Mark Krippel#