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02-0047
RWE Solutions — Hazardous Materials Safety Interpretation
Current as of source date Government source
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Page 1of Transportation U.S. Department 400 Seventh St., S.W. Washington, D.C. 20590 Research and MAY 10 2002 Administration Spec|al Programs Mr. Stanley H. Hodges RWE Solutions Ref. No.: 02-0047 3800 Fernandina Road Suite 200 Columbia, SC 29210-3854 Dear Mr. Hodges: This is in response to your letter dated January 25, 2002, requesting clarification of the provisions in § 173.435 regarding the proper methodology and A2 values that should be utilized for transport calculations for uranium radioisotopes under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Q1: When calculating transport parameters for waste materials that contain uranium isotopes, when should we utilize the individual radionuclide Az Values vs. the Az values delineated for the uranium on an enrichment basis [e.g. natural uranium, enriched uranium ≤ 5%) or depleted uranium]? Al: In § 173.403, Natural uranium (U(nat)) is defined as "uranium with the naturally occurring distribution of uranium isotopes." Depleted uranium (U(depleted) is "uranium containing less uranium-235 (U-235) than the naturally occurring distribution of uranium isotopes." Similarly, enriched uranium (U(enriched)) contains more U-235 than the naturally occurring distribution of uranium isotopes. Not said, but implied, is that U(depleted) or U(enriched) are uranium with the natural occurring distribution of uranium isotopes that has then been processed to reduce or increase the amount of U-235. higher enrichments are reached. This process will also gradually change the fractions of other uranium isotopes present, as Because of the above definitions, whenever radioisotopes of other elements are present in the material to be transported, the A value to be used to determine the appropriate packaging requirements is the effective A, value for the mixture, using the formula in § 173.433(d)(2) and using as input for that formula the fractional activities and the Az values of the individual nuclides present. In general, that includes the A2 values of the various uranium isotopes which may be present. An exception may be made if it is clear from process knowledge that none of the uranium in the waste material came from uranium enriched to greater than 5% by mass of U-235, and that none of the uranium present had previously been irradiated (reprocessed). In that case, when applying the mixture formula, an unlimited Az value may be assumed for all isotopes of uranium present. 173.435 020047#
Page 2• Q2: Since my waste does not contain U-230, U-232 and U-233, would these isotopes also be treated in a similar manner, if they were present? A2: No. Since these isotopes are not normally present in measurable quantities in natural uranium or uranium enriched to less than 5% by mass of U-235, if they are detected, the fractional activity of each, divided by each respective A, value, should be used in the mixture formula. Q3: If analytical data are not available for the individual uranium radionuclides, can we use the values based on enrichment or do we need to obtain additional analytical data to determine the uranium isotopic distribution in the package waste? A3: If it is known that all uranium in the waste had the same enrichment, standard activity ratios for each of the uranium isotopes present for that enrichment may be assumed. I Ietermine fee rahas experimentalyichment is present in the waste, it is preferable to I hope this information is helpful. Sincerely, Hattie L. Mitchell, Chief Regulatory Review and Reinvention Office of Hazardous Materials Standards#
Page 3; FEB. 7.2002 4:25PM NO. 987 P.2 Betts 5173.435 RAM RVE 02-0047 Solutions January 25, 2002 MI. Edward T. Mazzullo U.S. DOT/RSPA (DHM-10) Director, Office of Hazardous Materials Standards 400 7th Street S.W. Washington, D.C. 20590-0001 Subject: Uranium Isotope A, Values for Transport Calculations 49 CFR 173.435 Clarification Request - Proper Soloction of Dear Mr. Mazzullo: /This letter is being written to you to request written clarification on the proper Uranium radioisotopes. methodology and Az values that should be utilized for DOT transport calculations for The table following the text of this letter is an excerpt from the Code of Fedoral Regulations Title 49 Section 173.435 entitled "Table of Al and Az Values for he individual uranium radionuclidos in addition to limits based on its enrichment. Radionuclides", The element Uranium has individual A, and Ag limits delineated fo: When calculating transport parameters for waste matorials that contain uranium values delineated for the uranium on an enrichment basis [e.g. U (natural), I sotopes, when should we utilize the individual radionuclide Az values vs. the A (enriched ≤ 5%), U (enriched > 5%) or U (depleted)]? values for uranium on an limit as delineated in 49 CFR 173.425. RWE NUKEM Corporation utilized the individual uranium values for U-234 and I-236 and an A, value of nrichment of 5%. For uranium enrichment percentages greater than 5%, I hac COUT FE 2920-16 200 60321100 49CFR173.435. Missin Statement: If analytical data is not available for the individual uranium radionuclides, can the values based on onrichment be used or do we need to obtain additional analytical data to determine the uranium isoropic distribution in the package waste?#
Page 4; FEB. 7.2002 4:25PM NO.987 P.3 Page 2 of2 January 25, 2002 Letter to Mr. Edward T. Mazzullo RWE Subject: 49 CRR. 173.495 Clarification Request Solutions I would like to thank you in advance for your attention to this clarification request. 5848. Should you have any questions, please do not hesitate to contact me at 803-214 Sincerely, Distoff Sr. Project Manager Stanley M. Hodges, J. 49 CHR 173.435 - "Thble of A, and A, Values for Radionuclides" (Values for Vinnium Radionuclides) Radionuclide Symbol of Element and U-230 stomic number U-233 U-232 Uranium(92) A, (TBg) 4Q AI (Ci) A, (T3g) 38109 Ix10% 0.270 A, (Ci) (TBg/e) (Cilp) Specifio Activisy 1030 5w 81L Unlimited 270 1x10 8.11x10" 2.7x10 U-294 U-236 U-235 Unlimited 10 270 Ix10 2,70x10~ 8.3x10 2.2x10 Unlimited 270 Jnlimitec 2.70x10* 3.6x10% 2.3x101 62x10% 2.7x10" Unlimited 1x10 8.0x10 2.4x109 6.Sx10% 2.2x10% U-238 1.2x10° 3.4x10% U (narural) Unlimited Unlimited Unlimited : Unlimited 2.6x108 7.1x107 U (onrichod - 5% or less Unlimited Unlimited Unlimited Unlimited (sea §173.434) than 5%) I (enriched - more 10 270 1x102 2,70x10° (sec §173.434) U (depleted) Unlimited Unlimited Unlimited Unlimited (Gcc $173.434)#
This material provides agency context. It does not replace binding regulatory text, and its legal effect depends on the underlying authority and facts.