【国外标准】 Standard Guide for Unrestricted Disposition of Bulk Materials Containing Residual Amounts of Radioactivity

6.1 Materials encountered during D&D may contain residual radioactivity varying in amounts from that in irradiated fuel to barely detectable quantities in or on building materials. It is clear that highly radioactive materials have to be disposed as radioactive waste pursuant to 10 CFR 60 and 10 CFR 61. Conversely, it is not reasonable to expend a disproportionate amount of resources to isolate materials that contain minute quantities of radioactive materials that will not cause even statistically measurable health effects.6.2 This guide provides a rationale and methodology for distinguishing between materials that contain sufficient radioactivity to warrant isolation of some type (such as storage awaiting decay, near-surface disposal, disposal with intruder protection, or placement in a deep repository) from materials with insignificant radioactive content. Materials with insignificant radioactive content can be recycled in the economy or disposed of in conventional (landfill) facilities without adverse health effects. Materials that meet the criteria identified in this guide are not simply excluded from regulation because they do not fall precisely in the regulatory scope. They are sufficiently free of radioactive material so that no further efforts at control are justified for radiation protection purposes. Therefore, the release of materials for unrestricted use in accordance with this guide meets the criteria for being an “as low as reasonably achievable” (ALARA) activity.6.3 For the purpose of this guide, the return of materials containing residual radioactivity to society without regulatory restrictions is referred to as “unrestricted release based on the absence of the credible potential for adverse health effects.” This guide asserts that materials recycled this way will have no statistically measurable health effects regardless of use. It does not guarantee that the materials are suitable for use in every possible application, for example, trace amounts of radionuclides in materials may not be acceptable for certain photographic and electronic applications.6.4 This guide also asserts that the owner of the materials is responsible for ensuring that society's criteria for “no measurable health effects” is met before release, and that the responsibility for providing materials with the purity required for a special application rests not with the owner, but with the developer of that application.1.1 This guide provides an approach for developing a basis for obtaining approval for release of bulk materials to be removed from a decontamination and decommissioning (D&D) or environmental remediation site from regulatory control. This would be addressed in the decommissioning plan (Guide E1281). Fig. 1 follows the logic described in the MARSAME for determining the materials that could be considered for release. Materials that negotiate this logic tree are referred to as “candidate for release based on dose.”1.2 For purposes of this guide, bulk materials shall consist of, for example, building materials, concrete rubble, soils, and internally contaminated or activated equipment and facility components.1.3 This guide is intended to apply to those equipment and materials to be removed from the site for their disposition as opposed to real property (buildings and grounds) that are to remain.1.4 Warning—Breathing of asbestos dust is hazardous. Asbestos and asbestos products present demonstrated health risks for users and for those with whom they come into contact. In addition to other precautions, when working with asbestos products, minimize the dust that results. For information on the safe use of chrysoltile asbestos, refer to “Safe Use of Chrysotile Asbestos: A Manual on Preventive and Control Measures.”1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific hazard see 1.4.