Waste Determination Process for Waste Incidental to Reprocessing
In rendering a waste determination, the U.S. Department of Energy (DOE) uses various technical analyses to evaluate whether certain radioactive waste byproducts should actually be classified as waste incidental to reprocessing (WIR), rather than high-level waste (HLW). These analyses usually include a performance assessment to evaluate the potential radiological dose attributable to the waste material, and determine whether the material will meet the applicable WIR criteria.
In such instances, the U.S. Nuclear Regulatory Commission (NRC) reviews DOE’s performance assessment to evaluate whether it demonstrates compliance with the objectives in Subpart C of Title 10, Part 61, of the Code of Federal Regulations (10 CFR Part 61), “Licensing Requirements for Land Disposal of Radioactive Waste.” For additional detail, see the following topics on this page, as well as the WIR Documents dataset and related Data Dictionary (both in Microsoft Excel format):
The performance objectives set forth in 10 CFR Part 61 include the following notable provisions to protect the public and the environment:
- 10 CFR 61.40, General requirement: Land disposal facilities must be sited, designed, operated, closed, and controlled after closure so that reasonable assurance exists that exposures to humans are within the limits established in the performance objectives in §§ 61.41 – 61.44.
- 10 CFR 61.41, Protection of the general population from releases of radioactivity: Concentrations of radioactive material which may be released to the general environment in ground water, surface water, air, soil, plants, or animals must not result in an annual dose exceeding an equivalent of 25 millirems to the whole body, 75 millirems to the thyroid, and 25 millirems to any other organ of any member of the public. Reasonable effort should be made to maintain releases of radioactivity in effluents to the general environment as low as is reasonably achievable (ALARA).
- 10 CFR 61.42, Protection of individuals from inadvertent intrusion: Design, operation, and closure of the land disposal facility must ensure protection of any individual inadvertently intruding into the disposal site and occupying the site or contacting the waste at any time after active institutional controls over the disposal site are removed.
- 10 CFR 61.43, Protection of individuals during operations: Operations at the land disposal facility must be conducted in compliance with the standards for radiation protection set forth in 10 CFR Part 20, “Standards for Protection Against Radiation,” except for releases of radioactivity in effluents from the land disposal facility, which shall be governed by § 61.41 of this part. Every reasonable effort shall be made to maintain radiation exposures as low as is reasonably achievable.
- 10 CFR 61.44, Stability of the disposal site after closure: The disposal facility must be sited, designed, used, operated, and closed to achieve long-term stability of the disposal site and to eliminate (to the extent practicable) the need for ongoing active maintenance of the disposal site following closure so that only surveillance, monitoring, or minor custodial care are required.
To determine whether DOE's performance assessment demonstrates compliance with the performance objectives listed above, the NRC's technical review includes evaluating the following aspects:
- Selected scenarios (specific features and processes at the disposal facility and in the surrounding area, such as the location of the potential release, location and general characteristics of the receptors, and applicable transport pathways through which radionuclides might reach the environment and pose a threat to the selected receptor groups)
- Long-term performance of the engineered barrier system used to store the WIR, limit the influx of water, and reduce the release of radionuclides at closure, in adverse conditions
- Release and migration of radionuclides through the engineered barrier system and geosphere (those deep-underground portions of the disposal facility where human contact is generally not assumed to occur)
- Radiological dose(s) to the selected receptor group(s)
- Removal of WIR to the maximum practical extent
- Demonstration of stability of the disposal site after closure
In addition, the NRC staff uses sensitivity analyses to establish the relative importance of modeled processes and input parameters that are highly uncertain and cannot clearly be established as conservative. In doing so, the staff performs its review in a risk-informed manner, focusing on those aspects that have the greatest impact on the estimated doses.
The NRC staff has periodically met with representatives from DOE, as well as the U.S. Environmental Protection Agency (EPA), and State regulatory agencies to discuss generic technical issues (GTIs) related to DOE’s waste determinations. These GTI meetings do not relate to any specific draft waste determination. Instead, they are intended to facilitate information sharing and promote better understanding of technical approaches and methodologies used in performance assessment. These GTIs include point-of-compliance, concentration averaging, model support, sensitivity and uncertainty analysis, cumulative impacts, estimating waste inventory and waste tank characterization, long-term grout performance, and long-term engineered cap performance. For additional detail, see the summary of GTI meetings available through the DOE Web site.