Reprocessing, definition

When RPs are granulated, the lengths of the fibers are reduced. On reprocessing with virgin materials or alone, their processability and product performances are definitely change. So it is important to determine if the change will affect final product performances. If it will, a limit for the amount of regrind mix should be determined or no recycled RP is to be used. Use it in some other product such as simulated wood. 

The classification system for nuclear fuel-cycle wastes in the United States can be characterized in the following way. First, as a consequence of the definition of high-level waste as waste from fuel reprocessing, all waste classes, including mill tailings, are defined based essentially on the source of the waste, rather than its radiological properties, and most of the definitions are not explicit in regard... 

High-level waste thus includes the concentrated wastes that arise from reprocessing of commercial or defense nuclear fuel that contain virtually all the fission products and transuranium radionuclides (except plutonium) in spent fuel. However, the definition does not mention the constituents of the waste, and it is only qualitative because concentrated is not quantified and the minimum fuel burnup that would yield high-level waste is not specified. Although the definition given above referred only to liquid (aqueous) waste, it is clear from further discussions in 10 CFR Part 50, Appendix F (AEC, 1970), that AEC intended that high-level waste also would include concentrated solid waste derived from liquid high-level waste that was suitable for permanent disposal. 

In considering a new definition of high-level waste in accordance with Clause (B) of NWPA, an important issue for NRC was whether this definition should encompass and quantify the traditional, source-based definition in Clause (A). Such a definition would quantify sufficient concentrations of fission products and the minimum concentrations of alpha-emitting transuranium radionuclides in high-level waste from fuel reprocessing. NRC indicated its preference that the definition in Clause (B) should not apply to the primary wastes from fuel reprocessing and that the definition in Clause (A) should continue to apply to all wastes previously considered to be high-level waste in accordance with source-based definitions (NRC, 1987). 

This definition is based on the source of the waste, but certain incidental wastes that arise from fuel reprocessing that contain lower concentrations of fission products and alpha-emitting transuranium radionuclides than the primary reprocessing wastes have been excluded on a case-by-case basis. 

Spent nuclear fuel is a form of high-level waste in some definitions [e.g., NRC s 10 CFR Part 60 (NRC, 1983)] but not in others [e.g., the Nuclear Waste Policy Act (NWPA, 1982)]. This inconsistency is not important, because spent fuel and the primary waste from fuel reprocessing have similar radiological properties and require similar precautions for safe handling, storage, and disposal. Spent fuel is not a waste until it is so declared. 

On account of this element s rarity, a separate account of it is desirable. Although the existence of promethium was predicted as early as 1913, it was not definitely discovered until 1945, since all isotopes are radioactive with the longest-lived isotope having a half-life of 17.7 years ( " Pm). It is a fission product of and is thus obtained on work-up of reprocessing wastes. 

Nevertheless, in many cases, there will be no possibility to use a suitable definition of electronic records to avoid the copying problem. Usually then the only way will be to provide the data itself and the methods used for the evaluation in a generally readable format, e.g., ASCII. Even though the reprocessability of the data is then not given as such, this approach at least guarantees that copies are available within the described limits. 

The CHINON A1 reactor was converted into a nuclear museum which is very much visited. The other gas cooled reactors are being dismantled. The MARCOULE G2 and G3 and CHINON A2 reactors have been dismantled to level 2. CHINON A3 have been dismantled to level 1 and is waiting for administrative authorization to undertake works to reach level 2. St-LAURENT A1 and A2 and BUGEY 1 reactors are in the stage of "definitive stop phase". That means all nuclear fuels have been discharged and transfered to the reprocessing plant. 

There is also uncertainty in the regulatory status of tertiary recycling when it does not result in the direct production of monomers suitable for polymerization into new plastic. The European Commission has at times supported the chemical recycling (depolymerization) of condensation polymers such as polyethylene terephthalate back to monomer (e.g., dimethyl terephthalate) as recycling for the purpose of government-mandated plastics recycling rate calculations, but not the liquefaction of polyolefin plastics back to petrochemical feedstocks for reprocessing in a refinery. Discussions around these types of definitional issues, and their environmental and economic implications, are likely to continue for many years to come. 

These benefits, particularly in a CAPRA application, have not yet been definitively defined in addition to the traditional interest of nitride (compatibility with sodium, good thermal conductivity and higher fuel density), this fuel would have the advantage of being in principle soluble in nitric acid, and therefore compatible with the PUREX reprocessing, in the entire Pu content range. This point has not yet been definitely demonstrated and studies on the solubility of nitrides witii a high Pu content, initiated in 1994, are to continue in 1995. 

In addition, we must agree on definitions of sustainable and closable global fuel cycle, recognizing the inexorable international pressure to restrict the number of countries who would be allowed to enrich and reprocess fuel. 

During reactor operation, small amounts of C are also formed in nuclear fuels. With regard to the radioactivity balance of the fuel during plant operation, this radionuclide is of no relevance however, considering its comparatively long halflife of 5736 years and its postulated release behavior from the fuel matrix under storage or accident conditions, it is of definite interest with respect to reprocessing or final disposal of the spent fuel. For these reasons, it is of importance to know the inventories as well as the chemical state of this radionuclide in the fuel. 

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