Waste resulting from reprocessing spent nuclear fuel that is determined to be incidental to reprocessing is reclassified from being high-level waste, and is managed as transuranic or low-level waste, depending on the characteristics of the waste. In U.S. Department of Energy (DOE) Order G 435.1, two procedures were established for determining whether waste may be treated as incidental to reprocessing. DOE emphasizes that incidental waste is not a new category of waste requiring separate management, but rather a categorization of waste in accordance with its hazardous characteristics rather than its origin.
The two procedures for determining if a waste may be considered incidental to reprocessing are citation and evaluation.
Citation—Waste incidental to reprocessing by citation includes spent nuclear fuel reprocessing plant wastes that meet the description included in the Notice of Proposed Rulemaking [34 FR (Federal Register) 8712] for proposed Appendix D, 10 CFR (Code of Federal Regulations) Part 50, Paragraphs 6 and 7.
Evaluation—The evaluation procedure is an approach to manage waste according to its hazard, even if it was not discussed in 34 FR 8712. The evaluation procedure may lead to management of the waste as either low-level waste or as transuranic waste.
Any determination that the high-level waste supernates are incidental would lead to them being managed as low-level waste. Consequently, only the low-level waste provisions of the determination are discussed further here, and transuranic waste criteria are omitted. Incidental wastes that will be managed as low-level waste must meet three criteria to be classified as low-level waste (U.S. Nuclear Regulatory Commission, 1999):
Criterion 1: The waste must receive processing to remove key radio-nuclides to the maximum extent that is technically and economically practical.
Criterion 2: The waste must be shown to be managed to meet safety requirements comparable to the performance objectives set out in 10 CFR Part 61, Subpart C. Safety requirements contained in DOE Order M 435.1 Section IV are held to be comparable to those in 10 CFR Part 61 (U.S. Nuclear Regulatory Commission, 1982).
Criterion 3: DOE has established a requirement that the waste must be incorporated in a solid physical form at concentrations that do not exceed the concentration limits for Class C commercially generated low-level waste. Class C limits were established by the U.S. Nuclear Regulatory Commission (USNRC) in 10 CFR 61.55 as an upper limit for wastes generally acceptable for near-surface disposal. Alternatively, DOE may establish alternative requirements for waste classification and characterization on a case-by-case basis (DOE Order G 435.1).
ROLE OF THE U.S. NUCLEAR REGULATORY COMMISSION IN INCIDENTAL WASTE DETERMINATIONS
The USNRC expects DOE to consult with it for waste streams for which there is some question of whether the waste is high-level waste. However, the USNRC has agreed that DOE has the discretion to make incidental waste determinations (memo for Commissioner Curtiss from J.M. Taylor, January 14, 1993). Owing to the ambiguity of these positions, DOE has agreed to keep the USNRC informed of any incidental waste determinations. DOE Order G 435.1-1 has recommended that the USNRC should be consulted for all determinations using evaluation. Owing to the difficulty and associated expense of evaluation determinations, DOE has urged its sites to de-emphasize the use of this approach, and to manage high-level wastes in a manner intended to permit disposal in a geological repository.
An agreement has been reached between DOE and the USNRC that DOE will manage wastes incidental to reprocessing. This includes internal DOE performance of all regulatory functions, as is typically done for DOE-generated low-level wastes. However, DOE has agreed to consult with the USNRC on any questionable determinations that a waste is incidental to reprocessing by the evaluation procedure (DOE Order G435.1-1, page II-16).
DETERMINATION OF HIGH-LEVEL WASTE SUPERNATES ASINCIDENTAL TO REPROCESSING
Determination of high-level waste supernates as incidental to reprocessing is a key administrative and regulatory precursor step to the direct grout option. The Savannah River Site has requested a review by the USNRC of their process to categorize the residual waste in the tanks as incidental (U.S. Nuclear Regulatory Commission, 1999), but has not yet requested a review of the process to categorize waste destined for the saltstone facility. Such a categorization is needed for either the direct grout op-
tion, or to categorize residual contamination in liquid wastes following any of the separation processes under consideration.
Recently, a USNRC staff requirements memorandum was sent to DOE concerning advice from USNRC regarding the determination of incidental waste at SRS and any advice warranted on the option of direct disposal of cesium in the saltstone (U.S. Nuclear Regulatory Commission, 2000). This memorandum indicates that DOE is responsible for determining whether the waste is incidental, and that the USNRC will not propose special criteria for alternate classification of the waste as Class C Low-Level Waste.
U.S. Nuclear Regulatory Commission. 1982. 10 CFR Part 61–Licensing Requirements for Land Disposal of Radioactive Waste, Final Rule. Federal Register 50, 38066, Washington, D.C.
U.S. Nuclear Regulatory Commission. 1999 (December 15). Classification of Savannah River Residual Tank Waste as Incidental . SECY-99-284, Washington, D.C.
U.S. Nuclear Regulatory Commission. 2000 (May). Staff Requirements– SECY-99-0284. Classification of Savannah River Residual Tank Waste as Incidental . Memorandum from A.L.V. Cook to W.D. Travers, Washington, D.C.