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Interpretation Response #05-0241 ([Envirocare of Utah, LLC] [Mr. Mark Ledoux])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Envirocare of Utah, LLC

Individual Name: Mr. Mark Ledoux

Location State: UT Country: US

View the Interpretation Document

Response text:

Jan 24, 2006


Mr. Mark Ledoux                     Reference No. 05-0241
Corporate Radiation Safety Officer
Envirocare of Utah, LLC
605 North 5600 West
Salt Lake City, Utah 84116

Dear Mr. Ledoux,

This is in response to your September 13, 2005 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) regarding the applicability of fissile material exceptions. Specifically, you ask whether § 173.453(c) of the HMR applies to waste generated at the Eastern Tennessee Technology Park (ETTP). You describe the waste as demolition debris from the K-25 and K-27 buildings with enriched uranyl fluoride as surface contamination on structural steel and as scale within process piping and equipment. Prior to transportation structural foam filling is placed in process equipment voids to restrict geometry changes.

The fissile material exception provided in § 173.453(c) applies when there are low concentrations of solid fissile material commingled with solid non-fissile material provided that there are at least 2000 grams of non-fissile material for every gram of fissile material and there are no more than 180 grams of fissile material distributed within 360 kg of contiguous non-fissile material.

Uranyl fluoride is highly soluble in water and is susceptible to change from a solid to liquid state under conditions normally incident to transportation. The potential for preferential movement of the fissile material separate from the non-fissile material gives no assurance that there will be no more than 180 grams of fissile material distributed within 360 kg of contiguous non-fissile material. Preparation of the metal debris to fill voids with structural foam is a step towards improved safety assurance, but such foam does not eliminate the potential for the uranyl fluoride changing from a solid state to a liquid state because of its high solubility in water.

Therefore, the exception in 173.453(c) does not apply to the situation you have described.

I hope this satisfies your inquiry. If we can be of further assistance, please contact us.



John A. Gale
Standards Development
Office of Hazardous Materials Standards

172.101, 173.403, 173.453

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
173.403 Definitions
173.453 Fissile materials-exceptions