Reprocessability studies

Since the system is processed as thermoplastics are processed, its reprocessability was studied under repeated cycles of extrusion in the MPT. Results of reprocessability studies are shown in Table 5. It is evident that after the first cycle viscosity increased slightly, which may be due to the orientation effect. In the subsequent cycles viscosity remained almost constant. Therefore, it is concluded that the zinc stearate plasticized zinc salt of m-EPDM is melt processable just as thermoplastics. 

Goode, J. H. and Stacy, R. G., "Head-End Reprocessing Studies with H. B. Robinson-2 Fuel," 0RNL/TM-6037, Oak Ridge National Laboratory, Oak Ridge, TN (1978). 

R. W. Rebholz et al.. Chemical Reprocessing Studies for the Liquid Metal Fuel Reactor Experiment, USAEC Report UCN-42, Union Carbide Nuclear Co., June 28, 1957. 

The throwaway fuel cycle does not recover the energy values present ia the irradiated fuel. Instead, all of the long-Hved actinides are routed to the final waste repository along with the fission products. Whether or not this is a desirable alternative is determined largely by the scope of the evaluation study. For instance, when only the value of the recovered yellow cake and SWU equivalents are considered, the world market values for these commodities do not fully cover the cost of reprocessing (2). However, when costs attributable to the disposal of large quantities of actinides are considered, the classical fuel cycle has been the choice of virtually all countries except the United States. 

The general goal in the recent efforts has been very practical — to ensure better control of Pu(IV) in low acid reprocessing steams through quantitative measurements of the parameters that determine polymer formation. Admittedly, similar studies have been conducted to some degree already, but... 

Mclsaac, L. D. Baker, J. D. Krupa, J. F. LaPointe, R. E. Meikrantz, D. H. Schroeder, N. C. "Study of Bidentate Compounds for the Separation of Actinides from Commercial LWR Reprocessing Waste," Allied Chemical Idaho Chemical Programs Report ICP-1180, Idaho Falls, Idaho, February 1979. 

Bond, W. Leuze, R. "Feasibility Studies of the Partitioning of Commercial High-Level Wastes Generated in Spent Nuclear Fuel Reprocessing Annual Progress Report for FY-1974," ORNL-5012, Oak Ridge, Tennesse, January 1975. 

If the product is to be used for pharmaceuticals the GMP rules must be obeyed during plant operation. All chemicals to be tested in clinical studies with humans must be prepared according to GMP. This leads to very detailed documentation since if you haven t documented it, you haven t done it . All procedures for manufacturing and changes in procedures are subject to approval by quality control departments. This decreases the flexibility in process development. Products that are contaminated too much must be reprocessed according to the GMP guidelines. All equipment to be used in the pilot plant must be validated before use. 

Environmental Fate. The environmental fate of americium has been extensively studied in relation to its introduction into the Irish Sea from the BNFL nuclear fuel reprocessing plant at Sellafield, United Kingdom (Belot et al. 1982 Bennett 1976 Bunzl et al. 1994, 1995 Malcolm et al. 1990 McCartney et al. 1994 McKay et al. 1994a Murray et al. 1978, 1979 Pattenden and McKay 1994 Walker et al. 1986). 

I know that there are advocates of reprocessing here today. We have concluded, however, that reprocessing is uneconomic and causes proliferation concerns. According to an Energy Resources International study, reprocessing will add about 40 percent to the price of fuel. But whether or not you share our views on reprocessing, geologic disposal of waste - for hundreds or thousands of years - is an issue that we all must face. 

DuPont carried out and supported research and development by others focused on conceptual design studies for an NRC licensed fuel recycle complex based on its successful reprocessing experience and lessons learned from that experience and the experience of others. The design studies were completed and reports issued in November 1978. Costs for the 3000 ton/ycar integrated fuel reprocessing/fabrication facility were estimated at 3.7 billion (1978 dollars). Special features ofthis facility design include ... 

However, one must be careful because in an LMXB the optical emission from the accretion disk (whether in the outer, cool regions or as reprocessed X-ray emission) can outshine the companion by a large factor. This makes spectral lines difficult to measure and also complicates the ellipsoidal light curve technique. The ideal systems to study are therefore transient systems, which undergo periods of active mass transfer (often for a few weeks to a few months) before lapsing into quiescence, where there is little to no mass transfer. During quiescence, the companion is still distorted by the gravity of the neutron star, hence the flux variations still occur, but without any contamination by the accretion disk. There is a relatively new approach similar to this that... 

If reprocessing of spent Th fuels is needed in the future, many drawbacks of the Thorex process can be avoided by using A, A -dialkylamides instead of TBP. It is known from studies of Pu(IV)-U(VI) separation with amides that U(VI)-Th(IV) separation in acidic medium is easier than with TBP. The advantages of amides over phosphates could probably be considered more freely for Thorex than for Purex plants because no Thorex plant has been built yet. The extraction behavior of Pa(V) has not been yet investigated but in view of the general chemical properties of the two extractants, smaller distribution ratios are expected with the A, A -dialkyl-amides. 

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