# Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Object - **operation:** document - **citation:** PHMSA Guidance, Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Object - **title:** Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Object - **source type:** guidance - **agency:** Pipeline and Hazardous Materials Safety Administration - **status:** guidance - **official:** true - **published on:** 1998-06-01 - **effective on:** 1998-06-01 - **summary:** Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Object Document ML15336A927.pdf (4.03 MB) A guidebook on the proper classification and packaging of low specific activity materials and surface contaminated objects. Issued Date: Monday, June 1, 1998 - **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-guidance-categorizing-and-transporting-low-specific-activity-materials-932e730b.json - **markdown:** https://regulus.evalyn.ai/document/phmsa-guidance-categorizing-and-transporting-low-specific-activity-materials-932e730b.md - **app url:** https://regulus.evalyn.ai/document/phmsa-guidance-categorizing-and-transporting-low-specific-activity-materials-932e730b - **source url:** https://www.phmsa.dot.gov/regulatory-compliance/phmsa-guidance/categorizing-and-transporting-low-specific-activity-materials **body:** Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Object Document ML15336A927.pdf (4.03 MB) A guidebook on the proper classification and packaging of low specific activity materials and surface contaminated objects. Issued Date: Monday, June 1, 1998 <<>> NUREG-1608 RAMREG-003 Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Objects Prepared by J. Cook, R. Lewis, E. Easton, NRC R. Boyle, DOT R. Pope, ORNL U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards U.S. Department of Transportation Research and Special Programs Administration <<>> AVAILABILl1Y NOTICE Availability of Reference Materials Cited in NRC Publications Most documents cited in NRC publications will be available from one of the following sources: 1. The NRC Public Document Room, 2120 L Street, NW., Lower Level, Washington, DC 20555-0001 2. The Superintendent of Documents, U.S. Government Printing Office, P. O. Box 37082, Washington, DC 20402-9328 3. The National Technical Information Service, Springfield, VA 22161-0002 Although the listing that follows represents the majority of documents cited in NRC publica- tions, it is not intended to be exhaustive. Referenced documents available for inspection and copying for a fee from the NRC Public Document Room Include NRC correspondence and internai NRC memoranda; NRC bulletins, circulars, information notices, inspection and investigation notices: licensee event reports; vendor reports and correspondence; Commission papers; and applicant and licensee docuw ments and correspondence. The following documents in the NUREG series are available for purchase from the Government Printing Office: formal NRC staff and contractor reports, NRG-sponsored conference pro· ceedings, international agreement reports, grantee reports, and NRC booklets and bro- chures. Also available are regulatory guides, NRC regulations in the Code of Federal Regula- tions, and Nuclear Regulatory Commission Issuances. Documents available from the National Technical Information Service include NUREG-series reports and technical reports prepared by other Federal agencies and reports prepared by the Atomic Energy Commission, forerunner agency to the Nuclear Regulatory Commission. Documents available from public and special technical libraries include all open literature items, such as books, journal articles, and transactions. Federal Register notices, Federal and State legislation, and congressional reports can usually be obtained from these libraries. Documents such as theses, dissertations, foreign reports and translations, and non-NRC con- ference proceedings are available for purchase from the organization sponsoring the publica- tion cited. Single copies of NRC draft reports. are available free, to the extent of supply, upon written request to the Office of Administration, Distribution and Mail Services Section, U.S. Nuclear Regulatory Commission, Washington DC 20555-0001. Copies of industry codes and standards used in a substantive manner in the NRC regulatory process are maintained at the NRC Library, Two White Flint North, 11545 Rockville Pike, Rock- ville, MD 20852-2738, for use by the public. Codes and standards are usually copyrighted and may be purchased from the originating organization or, if they are American National Standards, from the American National Standards Institute, 1430 Broadway, New York, NY 10018-3308. <<>> NUREG-1608 RAMREG-003 Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Objects Manuscript Completed: June 1998 Date Published: July 1998 Prepared by J. Cook, R Lewis, E. Easton, U.S. Nuclear Regulatory Commission R. Doyle, U.S. Department of Transportation R. Pope, Oak Ridge National Laboratory Spent Fuel Project Office Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Research and Special Programs Administration U.S. Department of Transportation 400 Seventh Street, SW Washington, DC 20590-0003 <<>> <<>> ABSTRACT The primary purpose of this guidance is to assist shippers in preparing low specific activity materials (LSA) and surface contaminated objects (SCOs) for shipment in compliance with Federal regulations. Guidance is provided in question and answer format on the classification, categorization, packaging and transportation of LSA and SCOs, including the definition of LSA and SCOs, the determination of distribution of activity in LSA material or on SCO surfaces, mixing LSA and SCOs in a package, radiation level measurements, and various other aspects of transporting LSA and SCOs. There are many requirements, other than those addressed herein, imposed in the shipment of LSA and SCOs. The guidance represents one or more methods of demonstrating compliance with the regulatory requirements for LSA material and SCOs that have been found acceptable to NRC and DOT; however, additional methods may also be found to be acceptable with adequate justification. iii NUREG-1608 <<>> <<>> CONTENTS ABSTRACT .............................................................. iii ACKNOWLEDGMENTS ..................................................... x 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 2 BACKGROUND ........................................................ 2-1 3 SURFACE CONTAMINATED OBJECTS .................................... 3-1 3.1 Categorizing a Class 7 (Radioactive) Material as an sea ................ 3-1 3.1.1 If a contaminated object is also activated, can it be categorized as an SCO? ............................................. 3-2 3.1.2 Is there a contamination level below which an object does not need to be categorized as an SCO or as radioactive material, n.o.s.? .......................................... 3-2 3.1.3 How should a contaminated object with a limited quantity of radioactive material be categorized? .......................... 3-2 3.1.4 Must all radionuclides be individually accounted for, and is there an applicable sum or fractions rule which should be applied in assessing compliance with the sea contamination limits? ..................................... 3-3 3.1.5 Are there any constraints on mixing SCOs with nonhazardous materials in a packaging? ................................... 3-3 3.1.6 Can an object which might qualify as an sea-I be categorized and shipped as an SC0-11? ................................. 3-3 3.2 Clarification of Terms Used in the sea Definitions .................... 3-3 3.2.1 What is contamination? ................................... 3-4 3.2.2 What is fixed contamination and non-fixed (removable) contamination? .......................................... 3-4 3.2.3 What are accessible surfaces and inaccessible surfaces for seas? ... 3-5 v NUREG-1608 <<>> Contents 3.3 Quantity-Based Method for Compliance With the SCO Definitions ......... 3 .. 5 3.3.1 What is a practical method for categorizing an object as SCO for shipment under exclusive-use in a strong tight container [using 49 CPR 173.427(b)(3)]? ...................... 3-6 3.3.2 What methods should be used for categorizing an object containing greater than 1 A2 as SCO? ......................... 3-7 3 .4 Determining Contamination Levels on Surfaces . . . . . . . . . . . . . . . . . . . . . . . 3-8 3.4.1 What methods are acceptable for determining fixed and nonRfixed contamination on accessible and inaccessible surfaces of SCOs? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 -8 3.4.2 When taking measurements, how can one distinguish fixed accessible contamination from total inaccessible contamination? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8 3.4.3 How can fixed alpha contamination be measured? ................ 3-9 3.4.4 How can contamination level measurements be averaged? .......... 3-9 3.4.5 How is wiping efficiency used in the determination of contamination on package external surfaces and SCOs? .......... 3-10 4 LOW SPECIFIC ACTIVITY MATERIAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.1 Categorizing a Class 7 (Radioactive) Material as LSA .................. 4-1 4 .1. 1 What general categories of materials are intended to be shipped as LSA? ......................................... 4-1 4.1.2 Is there a contamination limit for an LSA material's surfaces? ....... 4-2 4.1.3 When an unshielded LSA material exceeds 10 mSv/hr (1 rem/hr) at 3 m (9.9 ft), what is the proper shipping name? ....... 4-3 4 .1. 4 Is there an object size below which collections of small, contaminated objects may be categorized and shipped as LSA material (as opposed to SCOs)? ............................. 4-3 4 .1. 5 Can activated metals, or a radioactive material which is solidified or absorbed on nonradioactive material, be categorized as LSA-11? .................................... 4-4 NUREG-1608 vi <<>> Contents 4 .1. 6 Can the mass of grout or binding agents used in or on an object be included in the LSA specific activity or unshielded dose rate determinations? . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 4 .1. 7 Can leach testing for disposal ( 10 CFR Part 61) substitute for the LSA-III leach test? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 4.1.8 Is it acceptable to use representative samples in the LSA-111 leach test? ....................................... 4-5 4.1.9 Is it necessary to leach test activated metals? .................... 4-6 4.2 Clarification of Tenns Used in the LSA Definitions ..................... 4-6 4.2.1 What is the intent of the terminology rubble, other debris and activated material in the LSA-I definition? ............ 4-6 4.2.2 What is the difference between distributed throughout and essentially uniformly distributer.I? ......................... 4-7 4.2.3 What practical techniques can be used for demonstrating the activity in an LSA material is distributed throughout or essentially uniformly distributed, as applicable? . . . . . . . . . . . . . . . 4-7 4.2.4 Can compliance with NRC's "Branch Technical Position on Concentration Averaging and Encapsulation" be used to demonstrate that a IJlixture of candidate LSA materials are distributed throughout or essentially uniformly distributed, as applicable? .................................. 4-8 4.2. 5 What is a combustible solid with respect to the conveyance activity limit for LSA material of 100 A2? . . . . . . . . . . . . . . . . . . . . . . 4-9 4.2.6 What was the misprint in NRC's and DOT's September 28, 1995, Federal Register final rules (60 FR 50292 and 60 FR 50248) regarding the tenns distributed throughout and essentially uniformly distributer.I? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10 5 UNSHIELDED DOSE RATE LIMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5. 1 Intent of the Dose Rate Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.1.1 Where does the unshielded dose rate limit apply? . . . . . . . . . . . . . . . 5-2 vii NUREG-1608 <<>> Contents 5.1.2 Do the possible effects ofredistribution of the LSA material or SCOs in transport (and resultant loss of self-shielding) need to be assessed? ........................... 5-2 5.1.3 Can liners (e.g., disposal containers), waste binders, or other packaging materials be considered in complying with the dose rate limit? ................................... 5-2 5.1.4 If slightly contaminated/activated materials are shipped in the same package as other LSA material, how should the external dose rate be calculated and/ or measured for these non-uniform sources? ................................. 5-3 5.2 Quantity-Based Method for Compliance With the Dose Rate Limit ......... 5-3 5 .2.1 What quantity of LSA material or SC Os in a package can be assumed, without further analysis, to comply with the dose rate limit? ....................................... 5-3 5.2.2 For explicit demonstrations of compliance with the dose rate limits, which methods are acceptable? ...................... 5-4 5.2.3 If package measurements and back-calculations to unshielded dose rates are used, how can account be taken for the effects of the packaging (e.g., the smoothing of radiation readings, and the masking of "hot spots")? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 6 PACKAGING AND SHIPPING REQUIREMENTS ............................. 6-1 6.1 Mixing LSA Materials and SC Os Together or with Other Hazardous Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6.1.1 What is the general rule for mixing LSA material and SC Os in a single package? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6.1.2 What is the proper shipping name for a mixed LSNSCO package? ...................................... 6-2 6.1.3 When a material meets an LSA material definition but also the definition of another Hazard Class (e.g., corrosive liquid, n.o.s., PG I), how should the material be classified and prepared for shipment? ................................ 6-2 NUREG-1608 viii <<>> Contents 6.2 Pre-Shipment Processing of LSA Material and SCOs . . . . . . . . . . . . . . . . . . . 6-3 6.2.1 How can accessible surfaces be converted into inaccessible surfaces? ..................................... 6-3 6.2.2 How can non-fixed (removable) contamination be rendered fixed? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 6.2.3 Can grout or binding agents or encapsulating materials be considered in LSA-specific requirements? .................... 6-3 6.2.4 Is there a requirement to document the determinations which show compliance with regulatory requirements including categorization of a material or object as LSA material or sea and the determination of unshielded dose rate? .............................................. 6-4 6.3 Packaging Requirements for LSA Materials and SCOs .................. 6-4 6.3. l What are the design requirements for a strong, tight package? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 6.3.2 Can any LSA material or SCOs be shipped unpackaged or as its own packaging? .... , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 6.3.3 Could a shipper package and transport LSA material inside a packaging that would otherwise meet the definition of SCO? ............................................... 6-7 6.3.4 What are the rules for continued use of NRC-certified Type A LSA packages "grandfathered" by 10 CFR 71.52? Is exclusive-use required? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 7 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 APPENDIX A Regulatory Process for Categorizing Materials and Objects as LSA Material or SCOs and Selecting Packaging Options ...................................... A - 1 1X NUREG-1608 <<>> ACKNOWLEDGMENTS This guidance was jointly developed by the U.S. Department of Transportation and the U.S. Nuclear Regulatory Commission, with technical support from the Oak Ridge National Laboratory (ORNL). In preparing the guidance, input was obtained from nuclear industry representatives, including NRC licensees, those shipping radioactive materials for the U.S. Department of Energy, and personnel involved in auditing or inspecting the packaging and transport of low specific activity materials and surface contaminated objects. NUREG-1608 x <<>> 1 INTRODUCTION Large volumetric quantities of low-level radioactive waste (LLW) have historically been shipped as low specific activity (LSA) material. In addition, radioactive ores, plant maintenance and outage equipment, and U.S. Department of Energy (DOE) wastes have typically been categorized as LSA. The regulations take into account the inherent properties of LSA materials and surface contaminated objects (SCOs), and allow for less-strict packaging requirements as compared to other radioactive materials, while retaining comparable levels of satety at lower costs. Changes to NRC regulations in Title 10 of the Code of Federal Regulations, Part 71, "Packaging and Transportation of Radioactive Materials" (NRC, 1996a), and to DOT regulations in Title 49 of the Code of Federal Regulations, Part 172 - 178, "Shippers General Requirements for Shipments and Packaging" (DOT, 1996) have changed the regulatory framework under which LSA materials are shipped. These revised regulations, which became effective April 1, 1996, generally make domestic regulations for the safe transportation of radioactive materials compatible with requirements of the International Atomic Energy Agency's (IAEA) Safety Series 6, Regulations for the Safe Transport of Radioactive Material, 1985 edition (as amended 1990) (IAEA, 1990a). Under the previous regulations, the old LSA material category included as a subcategory, requirements for SCOs. In contrast, under the revised rules, the scheme for shipping these materials has been refined such that SCOs are now defined as their own category. At first inspection, this differentiation between the two types of materials seems clear and definitive. However, the wording of the regulations, and practical considerations in characterizing, categorizing, handling, packaging, and transporting these materials, result in some uncertainty as to consic;;tent, practical, and acceptable implementation of the revised requirements. Under the revised regulations, it is expected that most equipment will be categorized for shipment as SC0-11, whereas most waste will be categorized as LSA-11. There will probably be many exceptions to this generalization, including a variety of materials and objects whose characteristics (both physical and radiological) are uncertain or difficult to characterize. This guidance is intended to assist both shippers and regulators in applying the regulatory requirements for LSA material and SCOs properly. It should be recognized that no single document could address all issues related to the transport of these materials and objects. This guidance, which is presented in the form of questions and answers, is provided in four sections addressing: • issues related specifically to SCOs (Section 3); • issues related specifically to LSA material (Section 4); • issues relating to determination of the dose rate 3 m (9.9 ft) from the unshielded material, object or collection of objects (Section 5); and • issues relating to the preparations for shipment and the packaging of LSA material and SCOs (Section 6). In addition, an appendix (Appendix A) provides a logic flow process, based on the domestic regulations (DOT, 1996; NRC, 1996), which may be used to guide the characterization and 1-1 NUREG-1608 <<>> Introduction categorization of materials and objects as LSA material and SCOs. This appendix also contains a table which can be used to define packaging options available to shippers in the United States based upon the results of the characterization guided by the logic flow diagrams. The questions asked and answered in Sections 3 through 6 of this guidance are also identified in the diagrams presented in the appendix. This Guidance was published in draft form for public comment. NRC and DOT appreciate the efforts on the part of all contributors, and have attempted to address the comments to the extent practicable. However, comments that, in the opinion of NRC and DOT staff, were unclear, inaccurate, contradictory to regulatory requirements, or non-compelling, were not adopted. Nothing contained in this guide may be construed as having the force and effect of NRC or DOT regulations, or as relieving any shipper or licensee from compliance with the requirements of 10 CFR Part 71, 49 CFR Part 173, or any other applicable regulation. The guidance describes one or more methods of demonstrating compliance with the regulatory requirements for LSA material and SCOs that NRC and DOT have found acceptable. However, use of these methods is not mandatory. Methods other than those described here may also be found to be acceptable based on reseasoned argument, or other adequate justification. Shippers are reminded that it is their responsibility to be able to demonstrate that their methods satisfy applicable regulatory requirements. NUREG-1608 1-2 <<>> 2 BACKGROUND Although the new regulations for LSA material and SCOs are more prescriptive than were the previous regulations, DOT and NRC personnel have not observed a major economic or practical impact of the revised rules on the shipment of waste as LSA material or contaminated objects as SCOs. Specifically, experience shows that such activities have continued to take place in a safe manner under the new rules. However, because of the more prescriptive nature of the new rules, many questions have been asked, and it was determined by DOT and NRC that guidance on the new LSA material and SCO requirements would benefit both the regulated and the regulators. Areas of uncertainty in the revised regulations include: (a) (b) (c) (d) definitions, classification and categorization of materials and objects, determination of distribution of activity in LSA material or on SCO surfaces, determinations of the dose rate from the unshielded material or object, and preparation of materials and objects and selection of proper packaging for transport. Many of these are related to changes made in the regulations, where, in addition to providing a category for SCOs separate from LSA materials: (1) LSA materials are further divided into three subcategories (LSA-I, LSA-II, and LSA-III), and SCOs are further divided into two subcategories (SCO-I and SC0-11); (2) the LSA material subcategory definitions make distinctions between the terms essentially uniformly distributed and distributed throughout depending upon the subcategory of LSA material; (3) specific activity limits for LSA material have been tied to each nuclide's Ai value, and have increased substantially for most nuclides [the A2 quantity is the amount of normal form radioactive material which can be transported in a non-accident resistant, Type A package - see, for example 49 CFR 173.433 (DOT, 1996)]; (4) for SCOs~ the radioactive material contamination is distributed on the surfaces of objects that are not themselves radioactive, and the definitions distinguish between fixed and non-fixed (i.e., removable) contamination on accessible surfaces but combines them for inaccessible surfaces; (5) NRC certification of the package design for shipment of some LSA materials and SCOs is no longer required unless the dose rate from the unshielded material exceeds 10 mSv/h (1 rem/h) at 3 m (9.9 ft); and (6) a new set of packages, industrial packages (IPs), has been authorized for use with LSA material and SCOs. 2-1 NUREG-1608 <<>> <<>> 3 SURFACE CONTAMINATED OBJECTS The previous regulations contained provisions for shipment of SC Os as a subset of LSA material. SCOs were included in the LSA material definition in the previous versions of both 10 CPR 71.4 and 49 CFR 173.403, and they were transported using the proper shipping name "Radioactive material, LSA." However, the previous regulations specified only limits for total (fixed plus non-fixed) contamination, did not specify accessible nor inaccessible surfaces, and allowed for averaging the contamination over a large area [i.e., 1 m2 (10.8 ft2)]. SCOs are no longer defined as a subset of LSAmaterial (DOT, 1996; NRC, 1996a). SCOs have their own proper shipping name, "Radioactive material, surface contaminated object," or "Radioactive material, SCO;" and they have their own United Nations identification number, "UN29 l 3 /' as specified in the hazardous material table [ 49 CFR 172.101 (DOT, 1996)]. The SCO definitions [49 CFR 173.403 (DOT, 1996) and 10 CPR 71.4 (NRC, 1996a)] now specify separate limits for fixed and non-fixed (removable) contamination on accessible surfaces, and a limit for fixed plus non-fixed contamination on inaccessible surfaces. Compliance with each of these limits is necessary for categorization of an item as an SCO. However, compliance does not necessarily imply the need for explicit measurements of the contamination levels, as further discussed herein. In general, objects that satisfy the SCO definition will not satisfy the LSA definition, and should not be shipped as such. However, there are some circumstances where it is appropriate to ship collections of small objects as LSA material (see Section 4.1.4), or to ship SCOs mixed with LSA material as LSA material (see Section 6.1). Section 3.1 provides guidance on materials which can be categorized as SCOs. Section 3.2 clarifies some of the technical terms used in the SCO definitions. Section 3.3 provides specific guidance for complying with the sea definitions, based on the quantity of radioactivity in a package. Section 3.4 provides guidance for determining contamination levels on surfaces. 3.1 Categorizing a Class 7 (Radioactive) Material as an SCO Categorizing an object contaminated with Class 7 (radioactive) material as an SCO is an option for transport as compared with categorizing the material as "Radioactive material, n.o.s.," with an identification number of "UN 2982." SCO means a solid object which itself is not radioactive, but which has Class 7 (radioactive) material distributed on its surfaces. Categorization as SCO provides some relief from the packaging requirements and communications requirements when compared with the alternative categorization of "Radioactive material, n.o.s." Objects that are themselves radioactive (e.g., activated objects) and that are also contaminated cannot generally be categorized as SCO. The exception to this is discussed below. Objects that are radioactive and contaminated may be categorized as LSA material insofar as the requirements specified in the LSA definition are complied with (see Section 4.1.2). 3-1 NUREG-1608 <<>> Surface Contaminated Objects If a contaminated object is also activated to an average specific activity level less than 70 Bq/g (2 nCi/g)~see 49 CFR 173.403 (DOT, 1996)-the object itself is not classified as radioactive material according to 49 CFR 173.403 (DOT, 1996); however, the presence of the contamination on the object may require that it be classified as a Class 7 (radioactive) material. For such an object, if the SCO definition is satisfied, the object should then be classified as Class 7, and shipped as an SCO. However, if a contaminated object is also activated to an average specific activity level in excess of 70 Bq/g (2 nCi/g), the object itself is classified as radioactive material according to 10 CPR 71.4 and 49 CFR 173.403 (DOT, 1996; NRC, 1996a). In this event, it may not be categorized as an SCO since SCOs are, by definition [49 CPR 173.403 and 10 CPR 71.4 (DOT, 1996; NRC, 1996a)], non-radioactive objects having radioactive-contaminated surfaces. International regulations (IAEA, 1990a) contain a threshold value for contamination, below which a nonradioactive object [i.e., an object having an average specific activity level less than 70 Bq/g (2 nCi/g)] can be shipped without regard to the radioactivity [See clarification of contamination in Section 3.2.1]. The contamination threshold value was inadvertently omitted from the 1996 DOT domestic regulatory revisions (DOT, 1989; DOT, 1996). Consequently, all objects which are themselves not radioactive, but are slightly contaminated, could still be construed to qualify as SCO-I. DOT is currently addressing this issue. In the interim: an object with external contamination may be considered to be excepted from classification as Class 7 (radioactive) material if: (1) contamination when averaged over each 300 cm2 (46.5 in2) of all surfaces is less than 0.4 Bq/cm2 00-5 µCi/cm2 ) for beta and gamma emitters and low toxicity alpha emitters, and is also less than 0.04 Bq/cm2 (10-6 µCi/cm2) for all other alpha emitters; and (2) the object itself has an average specific activity less than 70 Bq/g (2 nCi/g). Any radioactive material that meets the requirements in 49 CPR 173.421, for excepted packages of limited quantities of Class 7 (radioactive) materials, can be shipped as "Radioactive Material, excepted package, limited quantity of material, UN2910.'' Note, however, that the activity per package in a normal form shipment (such as a contaminated object) would be limited to 10·3 A2 as given by Table 7 of 49 CPR 173.425. In such cases, there is no need to evaluate for compliance with the SCO contamination limits. NUREG-1608 3-2 <<>> Surface Contaminated Objects The SCO limits for contamination apply to any 300 cm2 (46.5 in2) • There is no requirement to do a sum of fractions (or "unity") rule. An object could be categorized as SCO, even if the surfaces were contaminated to both the limit for beta and gamma emitters and low toxicity alpha emitters, and to the limit for all other alpha emitters. Further, it could simultaneously have the contamination at the non-fixed (removable) limit on accessible surfaces, the fixed limit on accessible surfaces, as well as the limit on inaccessible surfaces. Since the SCO limits are stated in terms of activity (i.e., a beta-gamma limit and an alpha limit), there is no explicit nuclide dependence, and there is no need to sum or identify nuclide fractions for complying with the SCO definition. However, for shipping papers and labels (if not excepted from labeling), the nuclides must be identified and listed in accordance with the "95% sum of fractions" rule in 49 CFR §§ 173.433 and 173.435. ll_.•~tl•llll1illililllYjlllltlll Generally, waste management considerations may affect this practice. Three examples of packages containing SCOs mixed with nonhazardous materials include: SCOs mixed with non- radioactive materia]s (e.g., binding agents such as grout, or paint), as a means to transform non- fixed (removable) contamination into fixed contamination; as a means to make an accessible surface into an inaccessible surface; and as a means of adding structura] capability to the object to facilitate transport. Generally, the most appropriate category should be used to assure that response to any incidents is suitable for the materials present. However, for domestic transport, an SC0-11 has equivalent packaging requirements to an SC0-1 [49 CFR 173.427(b)(2), (b)(3) and (b)(4) (DOT, 1996)]. Further, since SC0-1 poses less of a contamination hazard than does SC0-11, categorization of an object as SC0-11 rather than as SC0-1 is a conservative approach. It is permissible to categorize radioactive material to higher categorization levels and package and ship them accordingly. Thus, it is permissible to categorize and ship an object which meets the SC0-1 definition as an SC0-11. Using a higher category for LSA materials may not be as straightforward, however, since the activity distribution and other conditions of the higher category must be satisfied. 3.2 Clarification of Terms Used in the SCO Definitions 3-3 NUREG-1608 <<>> Surface Contaminated Objects The definition of SC0-1 and SC0-11 in 10 CFR 71.4 and 49 CFR 173.403 (DOT, 1996; NRC, 1996a) contains several technical terms that are not explicitly defined, namely: contamination, both fixed and non-fixed, accessible suiface, and inaccessible suiface. This section provides additional clarification of the intent and meaning of these terms as used in the regulatory definitions. The terms apply to SCO' s as prepared for transport. For the purpose of complying with the SCO definitions in the domestic transportation regulations only (DOT, 1996; NRC, 1996a): Contamination is the presence of a radioactive substance on a suif ace in quantities in excess of 0.4 Bq/cm2 (10·5 µCi/cm2 , 22 dpmlcm2)for beta and gamma emitters and low toxicity alpha emitters or 0.04 Bq/cm2 (10-6 µCi/cm2 , 2.2 dpmlcm2 ) for all other alpha emitters. This is consistent with the definition for contamination provided in the international regulations (IAEA, l 990a), although a similar definition is not currently included in the U.S. domestic regulations. DOT is currently considering addition of the contamination definition to 49 CFR Part 173. This internationally-recognized lower limit for contamination serves a function in transport regulations comparable to the limit of 70 Bq/g (2 nCi/g) in the definition of radioactive material [ 49 CFR 173 .403 (DOT, 1996)]; i.e., materials having specific activities less than this limit are below the scope of the hazardous material regulations. A definition of contamination is needed in order to properly utilize the SCO category because the radioactive material definition of 70 Bq/g (2 nCi/g), which is based on an activity per unit mass, is not readily or directly applicable to SCOs. For nonactivated objects, dividing the activity in the contamination by the mass of the nonactivated object (to determine whether the object as a whole should or should not be defined as radioactive material) is generally not appropriate because it opens the possibility for a massive object with significant amounts of contamination on its surfaces falling below the regulatory threshold definition of radioactive material [i.e., specific activity would be less than 70 Bq/g (2 nCi/g)]. This situation is not consistent with the intent of the regulatory exemption limit and should be avoided. For the purposes of complying with SCO definitions: Fixed contamination is contamination that cannot be removed by the wipinf procedure defined in 49 CFR 173.443, to a detection level of 0.4 Bq/cm2 ( 10-5 µCi/cm ) for beta and gamma emitters and low toxicity alpha emitters, or 0.04 Bq/cm2 ( 1 o-6 µCi/cm2) for all other alpha emitters. Any other contamination is non-fixed contamination. NUREG-1608 3-4 <<>> Surface Contaminated Objects Although used in the definition of SCOs, there are no specific regulatory definitions of fixed contamination or non-fixed contamination. Therefore, other regulatory requirements [e.g., 49 CFR 173.443 (DOT, 1996)] have been considered in striving to develop consistent definitions. Specifically, 49 CFR 173.443(a)(l) describes a method for wiping a surface and determining the level of non-fixed (removable) contamination available from that surface. The text of 49 CFR l 73.443(a)(l) reads, in part, that the process for determining the level of non-fixed (removable) contamination consists of "wiping an area of 300 square centimeters· of the surface concerned with an absorbent material, using moderate pressure, and measuring the activity on the wiping material. Sufficient measurements must be taken in the most appropriate locations to yield a representative assessment of the non-fixed contamination levels." For the purposes of complying with SCO definitions: An accessible suiface is any suif ace which can readily be wiped by hand, using standard radiation-measuring techniques. Any other suif ace is an inaccessible surface. The accessible surface could be contacted if the packaging is removed by an accident. Thus, re- orientation of the SCO should be considered in identifying the accessible surface. However, a shipper does not need to consider damage to the object itself in an accident. For example, the bottom, or top, of an object would be accessible, but surfaces which must be reached by probing small openings would be inaccessible. A good rule of thumb is that, if a 300 cm2 (46.5 in2 ) area could be reached by a person's hand, it is an accessible surf ace. The phrasing, "by hand" is not meant to discourage use of as low as is reasonably achievable (ALAR.A) tools such as telescopic sampling instruments. The phrasing, "standard radiation-measuring techniques," is intended to imply practices similar to those used for complying with package contamination limits in 49 CFR 173.443. Note that this guidance would permit some objects, such as a tank, or a long 6 in. diameter pipe, to have some inaccessible surfaces that are readily measured/swiped. It is generally good practice to seal off the ends of pipes or tanks, such that a shock to the object could not result in contamination being easily released through the openings. 3.3 Quantity-Based Method for Compliance With the SCO Definitions Although pre-shipment determinations are required to demonstrate compliance with the applicable SCO definition, the regulations do not require measurements of contamination and/or radiation levels as the only means of accomplishing the determinations. Alternate methods or combinations of methods may be used to demonstrate compliance. These methods may include-in addition to measurements--calculations, reasoned arguments, and reference to previous shipments of similar materials or objects (see section 3.4.1). This section describes a reasoned argument approach to categorizing SCOs. The level of detail in these determinations is expected to be commensurate with the potential hazard that the contamination represents. The potential hazard is based on the quantity (i.e., activity) and radio toxicity of the Class 7 (radioactive) material to be shipped, and the 3-5 NUREG-1608 <<>> Surface Contaminated Objects combination of these two factors is associated with the relevant multiple or fraction of Ai, of the contaminants involved. Therefore, the first step in any shipment should be to determine the Ai fraction in the package in accordance with 49 CFR 173.433. For an SCO, the Ai fraction would typically be determined by analyzing representative swipes of the accessible surface, gross gamma counts, the total surface area, and assuming the fixed and inaccessible contamination had a similar radionuclide distribution from a previously determined facility-specific sample data base. The techniques for determining radionuclide content used in the previous regulations remain acceptable under the revised regulations (note, however, that the number of nuclides in the Table of A/Ai values has increased, and the values have changed). It is possible to make SCO determinations in a manner consistent with 10 CPR Part 20 requirements to maintain occupational exposures as low as is reasonably achievable (ALAR.A). In practice, NRC and DOT anticipate that almost all SCO packages will contain less than 1 Ai quantity, and therefore qualify for shipment in strong-tight containers (STCs) pursuant to 49 CPR 173.427(b)(3). A reasoned argument could be used to categorize the great majority of these candidate SCOs, without the need for detailed, quantitative measurement of fixed, accessible contamination or total (fixed plus non-fixed) inaccessible surface contamination. Both the beta- gamma Ai fraction and the alpha A2 fraction must be determined. The materials characterized using this reasoned argument would be shipped as "Radioactive - SCO." Demonstration of all of the following 4 conditions can be used to categorize a radioactive material as an SC0-11. It is expected that these conditions would allow categorization of a great majority of candidate SCO materials as SCO-II, without the need for detailed, quantitative measurement of fixed, accessible contamination or total inaccessible surface contamination. (1) (2) (3) ( 4) The shipment of the SCO-II is made pursuant to 49 CFR 173.427(b)(3), for domestic, exclusive-use transport of SCOs in strong-tight containers (STCs). Note that this requires that the radioactive material in the package totals to less than 1 A2 quantity as determined using the - **truncated:** true - **body characters:** 126059